/*********************************************************************
 *
 * $Id: YSerialPort.java 43580 2021-01-26 17:46:01Z mvuilleu $
 *
 * Implements FindSerialPort(), the high-level API for SerialPort functions
 *
 * - - - - - - - - - License information: - - - - - - - - -
 *
 *  Copyright (C) 2011 and beyond by Yoctopuce Sarl, Switzerland.
 *
 *  Yoctopuce Sarl (hereafter Licensor) grants to you a perpetual
 *  non-exclusive license to use, modify, copy and integrate this
 *  file into your software for the sole purpose of interfacing
 *  with Yoctopuce products.
 *
 *  You may reproduce and distribute copies of this file in
 *  source or object form, as long as the sole purpose of this
 *  code is to interface with Yoctopuce products. You must retain
 *  this notice in the distributed source file.
 *
 *  You should refer to Yoctopuce General Terms and Conditions
 *  for additional information regarding your rights and
 *  obligations.
 *
 *  THE SOFTWARE AND DOCUMENTATION ARE PROVIDED 'AS IS' WITHOUT
 *  WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
 *  WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS
 *  FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO
 *  EVENT SHALL LICENSOR BE LIABLE FOR ANY INCIDENTAL, SPECIAL,
 *  INDIRECT OR CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA,
 *  COST OF PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR
 *  SERVICES, ANY CLAIMS BY THIRD PARTIES (INCLUDING BUT NOT
 *  LIMITED TO ANY DEFENSE THEREOF), ANY CLAIMS FOR INDEMNITY OR
 *  CONTRIBUTION, OR OTHER SIMILAR COSTS, WHETHER ASSERTED ON THE
 *  BASIS OF CONTRACT, TORT (INCLUDING NEGLIGENCE), BREACH OF
 *  WARRANTY, OR OTHERWISE.
 *
 *********************************************************************/

package com.yoctopuce.YoctoAPI;
import java.util.Locale;
import java.util.ArrayList;

//--- (generated code: YSerialPort return codes)
//--- (end of generated code: YSerialPort return codes)
//--- (generated code: YSerialPort class start)
/**
 *  YSerialPort Class: serial port control interface, available for instance in the Yocto-RS232, the
 * Yocto-RS485-V2 or the Yocto-Serial
 *
 * The YSerialPort class allows you to fully drive a Yoctopuce serial port.
 * It can be used to send and receive data, and to configure communication
 * parameters (baud rate, bit count, parity, flow control and protocol).
 * Note that Yoctopuce serial ports are not exposed as virtual COM ports.
 * They are meant to be used in the same way as all Yoctopuce devices.
 */
@SuppressWarnings({"UnusedDeclaration", "UnusedAssignment"})
public class YSerialPort extends YFunction
{
//--- (end of generated code: YSerialPort class start)
//--- (generated code: YSerialPort definitions)
    /**
     * invalid rxCount value
     */
    public static final int RXCOUNT_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid txCount value
     */
    public static final int TXCOUNT_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid errCount value
     */
    public static final int ERRCOUNT_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid rxMsgCount value
     */
    public static final int RXMSGCOUNT_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid txMsgCount value
     */
    public static final int TXMSGCOUNT_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid lastMsg value
     */
    public static final String LASTMSG_INVALID = YAPI.INVALID_STRING;
    /**
     * invalid currentJob value
     */
    public static final String CURRENTJOB_INVALID = YAPI.INVALID_STRING;
    /**
     * invalid startupJob value
     */
    public static final String STARTUPJOB_INVALID = YAPI.INVALID_STRING;
    /**
     * invalid jobMaxTask value
     */
    public static final int JOBMAXTASK_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid jobMaxSize value
     */
    public static final int JOBMAXSIZE_INVALID = YAPI.INVALID_UINT;
    /**
     * invalid command value
     */
    public static final String COMMAND_INVALID = YAPI.INVALID_STRING;
    /**
     * invalid protocol value
     */
    public static final String PROTOCOL_INVALID = YAPI.INVALID_STRING;
    /**
     * invalid voltageLevel value
     */
    public static final int VOLTAGELEVEL_OFF = 0;
    public static final int VOLTAGELEVEL_TTL3V = 1;
    public static final int VOLTAGELEVEL_TTL3VR = 2;
    public static final int VOLTAGELEVEL_TTL5V = 3;
    public static final int VOLTAGELEVEL_TTL5VR = 4;
    public static final int VOLTAGELEVEL_RS232 = 5;
    public static final int VOLTAGELEVEL_RS485 = 6;
    public static final int VOLTAGELEVEL_TTL1V8 = 7;
    public static final int VOLTAGELEVEL_INVALID = -1;
    /**
     * invalid serialMode value
     */
    public static final String SERIALMODE_INVALID = YAPI.INVALID_STRING;
    protected int _rxCount = RXCOUNT_INVALID;
    protected int _txCount = TXCOUNT_INVALID;
    protected int _errCount = ERRCOUNT_INVALID;
    protected int _rxMsgCount = RXMSGCOUNT_INVALID;
    protected int _txMsgCount = TXMSGCOUNT_INVALID;
    protected String _lastMsg = LASTMSG_INVALID;
    protected String _currentJob = CURRENTJOB_INVALID;
    protected String _startupJob = STARTUPJOB_INVALID;
    protected int _jobMaxTask = JOBMAXTASK_INVALID;
    protected int _jobMaxSize = JOBMAXSIZE_INVALID;
    protected String _command = COMMAND_INVALID;
    protected String _protocol = PROTOCOL_INVALID;
    protected int _voltageLevel = VOLTAGELEVEL_INVALID;
    protected String _serialMode = SERIALMODE_INVALID;
    protected UpdateCallback _valueCallbackSerialPort = null;
    protected int _rxptr = 0;
    protected byte[] _rxbuff;
    protected int _rxbuffptr = 0;

    /**
     * Deprecated UpdateCallback for SerialPort
     */
    public interface UpdateCallback
    {
        /**
         *
         * @param function      : the function object of which the value has changed
         * @param functionValue : the character string describing the new advertised value
         */
        void yNewValue(YSerialPort function, String functionValue);
    }

    /**
     * TimedReportCallback for SerialPort
     */
    public interface TimedReportCallback
    {
        /**
         *
         * @param function : the function object of which the value has changed
         * @param measure  : measure
         */
        void timedReportCallback(YSerialPort  function, YMeasure measure);
    }
    //--- (end of generated code: YSerialPort definitions)


    /**
     *
     * @param func : functionid
     */
    protected YSerialPort(YAPIContext ctx, String func)
    {
        super(ctx, func);
        _className = "SerialPort";
        //--- (generated code: YSerialPort attributes initialization)
        //--- (end of generated code: YSerialPort attributes initialization)
    }

    /**
     *
     * @param func : functionid
     */
    protected YSerialPort(String func)
    {
        this(YAPI.GetYCtx(true), func);
    }

    //--- (generated code: YSerialPort implementation)
    @SuppressWarnings("EmptyMethod")
    @Override
    protected void  _parseAttr(YJSONObject json_val) throws Exception
    {
        if (json_val.has("rxCount")) {
            _rxCount = json_val.getInt("rxCount");
        }
        if (json_val.has("txCount")) {
            _txCount = json_val.getInt("txCount");
        }
        if (json_val.has("errCount")) {
            _errCount = json_val.getInt("errCount");
        }
        if (json_val.has("rxMsgCount")) {
            _rxMsgCount = json_val.getInt("rxMsgCount");
        }
        if (json_val.has("txMsgCount")) {
            _txMsgCount = json_val.getInt("txMsgCount");
        }
        if (json_val.has("lastMsg")) {
            _lastMsg = json_val.getString("lastMsg");
        }
        if (json_val.has("currentJob")) {
            _currentJob = json_val.getString("currentJob");
        }
        if (json_val.has("startupJob")) {
            _startupJob = json_val.getString("startupJob");
        }
        if (json_val.has("jobMaxTask")) {
            _jobMaxTask = json_val.getInt("jobMaxTask");
        }
        if (json_val.has("jobMaxSize")) {
            _jobMaxSize = json_val.getInt("jobMaxSize");
        }
        if (json_val.has("command")) {
            _command = json_val.getString("command");
        }
        if (json_val.has("protocol")) {
            _protocol = json_val.getString("protocol");
        }
        if (json_val.has("voltageLevel")) {
            _voltageLevel = json_val.getInt("voltageLevel");
        }
        if (json_val.has("serialMode")) {
            _serialMode = json_val.getString("serialMode");
        }
        super._parseAttr(json_val);
    }

    /**
     * Returns the total number of bytes received since last reset.
     *
     * @return an integer corresponding to the total number of bytes received since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int get_rxCount() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return RXCOUNT_INVALID;
                }
            }
            res = _rxCount;
        }
        return res;
    }

    /**
     * Returns the total number of bytes received since last reset.
     *
     * @return an integer corresponding to the total number of bytes received since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int getRxCount() throws YAPI_Exception
    {
        return get_rxCount();
    }

    /**
     * Returns the total number of bytes transmitted since last reset.
     *
     * @return an integer corresponding to the total number of bytes transmitted since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int get_txCount() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return TXCOUNT_INVALID;
                }
            }
            res = _txCount;
        }
        return res;
    }

    /**
     * Returns the total number of bytes transmitted since last reset.
     *
     * @return an integer corresponding to the total number of bytes transmitted since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int getTxCount() throws YAPI_Exception
    {
        return get_txCount();
    }

    /**
     * Returns the total number of communication errors detected since last reset.
     *
     * @return an integer corresponding to the total number of communication errors detected since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int get_errCount() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return ERRCOUNT_INVALID;
                }
            }
            res = _errCount;
        }
        return res;
    }

    /**
     * Returns the total number of communication errors detected since last reset.
     *
     * @return an integer corresponding to the total number of communication errors detected since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int getErrCount() throws YAPI_Exception
    {
        return get_errCount();
    }

    /**
     * Returns the total number of messages received since last reset.
     *
     * @return an integer corresponding to the total number of messages received since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int get_rxMsgCount() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return RXMSGCOUNT_INVALID;
                }
            }
            res = _rxMsgCount;
        }
        return res;
    }

    /**
     * Returns the total number of messages received since last reset.
     *
     * @return an integer corresponding to the total number of messages received since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int getRxMsgCount() throws YAPI_Exception
    {
        return get_rxMsgCount();
    }

    /**
     * Returns the total number of messages send since last reset.
     *
     * @return an integer corresponding to the total number of messages send since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int get_txMsgCount() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return TXMSGCOUNT_INVALID;
                }
            }
            res = _txMsgCount;
        }
        return res;
    }

    /**
     * Returns the total number of messages send since last reset.
     *
     * @return an integer corresponding to the total number of messages send since last reset
     *
     * @throws YAPI_Exception on error
     */
    public int getTxMsgCount() throws YAPI_Exception
    {
        return get_txMsgCount();
    }

    /**
     * Returns the latest message fully received (for Line, Frame and Modbus protocols).
     *
     * @return a string corresponding to the latest message fully received (for Line, Frame and Modbus protocols)
     *
     * @throws YAPI_Exception on error
     */
    public String get_lastMsg() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return LASTMSG_INVALID;
                }
            }
            res = _lastMsg;
        }
        return res;
    }

    /**
     * Returns the latest message fully received (for Line, Frame and Modbus protocols).
     *
     * @return a string corresponding to the latest message fully received (for Line, Frame and Modbus protocols)
     *
     * @throws YAPI_Exception on error
     */
    public String getLastMsg() throws YAPI_Exception
    {
        return get_lastMsg();
    }

    /**
     * Returns the name of the job file currently in use.
     *
     * @return a string corresponding to the name of the job file currently in use
     *
     * @throws YAPI_Exception on error
     */
    public String get_currentJob() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return CURRENTJOB_INVALID;
                }
            }
            res = _currentJob;
        }
        return res;
    }

    /**
     * Returns the name of the job file currently in use.
     *
     * @return a string corresponding to the name of the job file currently in use
     *
     * @throws YAPI_Exception on error
     */
    public String getCurrentJob() throws YAPI_Exception
    {
        return get_currentJob();
    }

    /**
     * Selects a job file to run immediately. If an empty string is
     * given as argument, stops running current job file.
     *
     * @param newval : a string
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_currentJob(String  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = newval;
            _setAttr("currentJob",rest_val);
        }
        return YAPI.SUCCESS;
    }

    /**
     * Selects a job file to run immediately. If an empty string is
     * given as argument, stops running current job file.
     *
     * @param newval : a string
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int setCurrentJob(String newval)  throws YAPI_Exception
    {
        return set_currentJob(newval);
    }

    /**
     * Returns the job file to use when the device is powered on.
     *
     * @return a string corresponding to the job file to use when the device is powered on
     *
     * @throws YAPI_Exception on error
     */
    public String get_startupJob() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return STARTUPJOB_INVALID;
                }
            }
            res = _startupJob;
        }
        return res;
    }

    /**
     * Returns the job file to use when the device is powered on.
     *
     * @return a string corresponding to the job file to use when the device is powered on
     *
     * @throws YAPI_Exception on error
     */
    public String getStartupJob() throws YAPI_Exception
    {
        return get_startupJob();
    }

    /**
     * Changes the job to use when the device is powered on.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the job to use when the device is powered on
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_startupJob(String  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = newval;
            _setAttr("startupJob",rest_val);
        }
        return YAPI.SUCCESS;
    }

    /**
     * Changes the job to use when the device is powered on.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the job to use when the device is powered on
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int setStartupJob(String newval)  throws YAPI_Exception
    {
        return set_startupJob(newval);
    }

    /**
     * Returns the maximum number of tasks in a job that the device can handle.
     *
     * @return an integer corresponding to the maximum number of tasks in a job that the device can handle
     *
     * @throws YAPI_Exception on error
     */
    public int get_jobMaxTask() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration == 0) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return JOBMAXTASK_INVALID;
                }
            }
            res = _jobMaxTask;
        }
        return res;
    }

    /**
     * Returns the maximum number of tasks in a job that the device can handle.
     *
     * @return an integer corresponding to the maximum number of tasks in a job that the device can handle
     *
     * @throws YAPI_Exception on error
     */
    public int getJobMaxTask() throws YAPI_Exception
    {
        return get_jobMaxTask();
    }

    /**
     * Returns maximum size allowed for job files.
     *
     * @return an integer corresponding to maximum size allowed for job files
     *
     * @throws YAPI_Exception on error
     */
    public int get_jobMaxSize() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration == 0) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return JOBMAXSIZE_INVALID;
                }
            }
            res = _jobMaxSize;
        }
        return res;
    }

    /**
     * Returns maximum size allowed for job files.
     *
     * @return an integer corresponding to maximum size allowed for job files
     *
     * @throws YAPI_Exception on error
     */
    public int getJobMaxSize() throws YAPI_Exception
    {
        return get_jobMaxSize();
    }

    public String get_command() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return COMMAND_INVALID;
                }
            }
            res = _command;
        }
        return res;
    }

    public int set_command(String  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = newval;
            _setAttr("command",rest_val);
        }
        return YAPI.SUCCESS;
    }


    /**
     * Returns the type of protocol used over the serial line, as a string.
     * Possible values are "Line" for ASCII messages separated by CR and/or LF,
     * "StxEtx" for ASCII messages delimited by STX/ETX codes,
     * "Frame:[timeout]ms" for binary messages separated by a delay time,
     * "Modbus-ASCII" for MODBUS messages in ASCII mode,
     * "Modbus-RTU" for MODBUS messages in RTU mode,
     * "Wiegand-ASCII" for Wiegand messages in ASCII mode,
     * "Wiegand-26","Wiegand-34", etc for Wiegand messages in byte mode,
     * "Char" for a continuous ASCII stream or
     * "Byte" for a continuous binary stream.
     *
     * @return a string corresponding to the type of protocol used over the serial line, as a string
     *
     * @throws YAPI_Exception on error
     */
    public String get_protocol() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return PROTOCOL_INVALID;
                }
            }
            res = _protocol;
        }
        return res;
    }

    /**
     * Returns the type of protocol used over the serial line, as a string.
     * Possible values are "Line" for ASCII messages separated by CR and/or LF,
     * "StxEtx" for ASCII messages delimited by STX/ETX codes,
     * "Frame:[timeout]ms" for binary messages separated by a delay time,
     * "Modbus-ASCII" for MODBUS messages in ASCII mode,
     * "Modbus-RTU" for MODBUS messages in RTU mode,
     * "Wiegand-ASCII" for Wiegand messages in ASCII mode,
     * "Wiegand-26","Wiegand-34", etc for Wiegand messages in byte mode,
     * "Char" for a continuous ASCII stream or
     * "Byte" for a continuous binary stream.
     *
     * @return a string corresponding to the type of protocol used over the serial line, as a string
     *
     * @throws YAPI_Exception on error
     */
    public String getProtocol() throws YAPI_Exception
    {
        return get_protocol();
    }

    /**
     * Changes the type of protocol used over the serial line.
     * Possible values are "Line" for ASCII messages separated by CR and/or LF,
     * "StxEtx" for ASCII messages delimited by STX/ETX codes,
     * "Frame:[timeout]ms" for binary messages separated by a delay time,
     * "Modbus-ASCII" for MODBUS messages in ASCII mode,
     * "Modbus-RTU" for MODBUS messages in RTU mode,
     * "Wiegand-ASCII" for Wiegand messages in ASCII mode,
     * "Wiegand-26","Wiegand-34", etc for Wiegand messages in byte mode,
     * "Char" for a continuous ASCII stream or
     * "Byte" for a continuous binary stream.
     * The suffix "/[wait]ms" can be added to reduce the transmit rate so that there
     * is always at lest the specified number of milliseconds between each bytes sent.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the type of protocol used over the serial line
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_protocol(String  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = newval;
            _setAttr("protocol",rest_val);
        }
        return YAPI.SUCCESS;
    }

    /**
     * Changes the type of protocol used over the serial line.
     * Possible values are "Line" for ASCII messages separated by CR and/or LF,
     * "StxEtx" for ASCII messages delimited by STX/ETX codes,
     * "Frame:[timeout]ms" for binary messages separated by a delay time,
     * "Modbus-ASCII" for MODBUS messages in ASCII mode,
     * "Modbus-RTU" for MODBUS messages in RTU mode,
     * "Wiegand-ASCII" for Wiegand messages in ASCII mode,
     * "Wiegand-26","Wiegand-34", etc for Wiegand messages in byte mode,
     * "Char" for a continuous ASCII stream or
     * "Byte" for a continuous binary stream.
     * The suffix "/[wait]ms" can be added to reduce the transmit rate so that there
     * is always at lest the specified number of milliseconds between each bytes sent.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the type of protocol used over the serial line
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int setProtocol(String newval)  throws YAPI_Exception
    {
        return set_protocol(newval);
    }

    /**
     * Returns the voltage level used on the serial line.
     *
     *  @return a value among YSerialPort.VOLTAGELEVEL_OFF, YSerialPort.VOLTAGELEVEL_TTL3V,
     *  YSerialPort.VOLTAGELEVEL_TTL3VR, YSerialPort.VOLTAGELEVEL_TTL5V, YSerialPort.VOLTAGELEVEL_TTL5VR,
     *  YSerialPort.VOLTAGELEVEL_RS232, YSerialPort.VOLTAGELEVEL_RS485 and YSerialPort.VOLTAGELEVEL_TTL1V8
     * corresponding to the voltage level used on the serial line
     *
     * @throws YAPI_Exception on error
     */
    public int get_voltageLevel() throws YAPI_Exception
    {
        int res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return VOLTAGELEVEL_INVALID;
                }
            }
            res = _voltageLevel;
        }
        return res;
    }

    /**
     * Returns the voltage level used on the serial line.
     *
     *  @return a value among YSerialPort.VOLTAGELEVEL_OFF, YSerialPort.VOLTAGELEVEL_TTL3V,
     *  YSerialPort.VOLTAGELEVEL_TTL3VR, YSerialPort.VOLTAGELEVEL_TTL5V, YSerialPort.VOLTAGELEVEL_TTL5VR,
     *  YSerialPort.VOLTAGELEVEL_RS232, YSerialPort.VOLTAGELEVEL_RS485 and YSerialPort.VOLTAGELEVEL_TTL1V8
     * corresponding to the voltage level used on the serial line
     *
     * @throws YAPI_Exception on error
     */
    public int getVoltageLevel() throws YAPI_Exception
    {
        return get_voltageLevel();
    }

    /**
     * Changes the voltage type used on the serial line. Valid
     * values  will depend on the Yoctopuce device model featuring
     * the serial port feature.  Check your device documentation
     * to find out which values are valid for that specific model.
     * Trying to set an invalid value will have no effect.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     *  @param newval : a value among YSerialPort.VOLTAGELEVEL_OFF, YSerialPort.VOLTAGELEVEL_TTL3V,
     *  YSerialPort.VOLTAGELEVEL_TTL3VR, YSerialPort.VOLTAGELEVEL_TTL5V, YSerialPort.VOLTAGELEVEL_TTL5VR,
     *  YSerialPort.VOLTAGELEVEL_RS232, YSerialPort.VOLTAGELEVEL_RS485 and YSerialPort.VOLTAGELEVEL_TTL1V8
     * corresponding to the voltage type used on the serial line
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_voltageLevel(int  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = Integer.toString(newval);
            _setAttr("voltageLevel",rest_val);
        }
        return YAPI.SUCCESS;
    }

    /**
     * Changes the voltage type used on the serial line. Valid
     * values  will depend on the Yoctopuce device model featuring
     * the serial port feature.  Check your device documentation
     * to find out which values are valid for that specific model.
     * Trying to set an invalid value will have no effect.
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     *  @param newval : a value among YSerialPort.VOLTAGELEVEL_OFF, YSerialPort.VOLTAGELEVEL_TTL3V,
     *  YSerialPort.VOLTAGELEVEL_TTL3VR, YSerialPort.VOLTAGELEVEL_TTL5V, YSerialPort.VOLTAGELEVEL_TTL5VR,
     *  YSerialPort.VOLTAGELEVEL_RS232, YSerialPort.VOLTAGELEVEL_RS485 and YSerialPort.VOLTAGELEVEL_TTL1V8
     * corresponding to the voltage type used on the serial line
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int setVoltageLevel(int newval)  throws YAPI_Exception
    {
        return set_voltageLevel(newval);
    }

    /**
     * Returns the serial port communication parameters, as a string such as
     * "9600,8N1". The string includes the baud rate, the number of data bits,
     * the parity, and the number of stop bits. An optional suffix is included
     * if flow control is active: "CtsRts" for hardware handshake, "XOnXOff"
     * for logical flow control and "Simplex" for acquiring a shared bus using
     * the RTS line (as used by some RS485 adapters for instance).
     *
     * @return a string corresponding to the serial port communication parameters, as a string such as
     *         "9600,8N1"
     *
     * @throws YAPI_Exception on error
     */
    public String get_serialMode() throws YAPI_Exception
    {
        String res;
        synchronized (this) {
            if (_cacheExpiration <= YAPIContext.GetTickCount()) {
                if (load(_yapi._defaultCacheValidity) != YAPI.SUCCESS) {
                    return SERIALMODE_INVALID;
                }
            }
            res = _serialMode;
        }
        return res;
    }

    /**
     * Returns the serial port communication parameters, as a string such as
     * "9600,8N1". The string includes the baud rate, the number of data bits,
     * the parity, and the number of stop bits. An optional suffix is included
     * if flow control is active: "CtsRts" for hardware handshake, "XOnXOff"
     * for logical flow control and "Simplex" for acquiring a shared bus using
     * the RTS line (as used by some RS485 adapters for instance).
     *
     * @return a string corresponding to the serial port communication parameters, as a string such as
     *         "9600,8N1"
     *
     * @throws YAPI_Exception on error
     */
    public String getSerialMode() throws YAPI_Exception
    {
        return get_serialMode();
    }

    /**
     * Changes the serial port communication parameters, with a string such as
     * "9600,8N1". The string includes the baud rate, the number of data bits,
     * the parity, and the number of stop bits. An optional suffix can be added
     * to enable flow control: "CtsRts" for hardware handshake, "XOnXOff"
     * for logical flow control and "Simplex" for acquiring a shared bus using
     * the RTS line (as used by some RS485 adapters for instance).
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the serial port communication parameters, with a string such as
     *         "9600,8N1"
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_serialMode(String  newval)  throws YAPI_Exception
    {
        String rest_val;
        synchronized (this) {
            rest_val = newval;
            _setAttr("serialMode",rest_val);
        }
        return YAPI.SUCCESS;
    }

    /**
     * Changes the serial port communication parameters, with a string such as
     * "9600,8N1". The string includes the baud rate, the number of data bits,
     * the parity, and the number of stop bits. An optional suffix can be added
     * to enable flow control: "CtsRts" for hardware handshake, "XOnXOff"
     * for logical flow control and "Simplex" for acquiring a shared bus using
     * the RTS line (as used by some RS485 adapters for instance).
     * Remember to call the saveToFlash() method of the module if the
     * modification must be kept.
     *
     * @param newval : a string corresponding to the serial port communication parameters, with a string such as
     *         "9600,8N1"
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int setSerialMode(String newval)  throws YAPI_Exception
    {
        return set_serialMode(newval);
    }

    /**
     * Retrieves a serial port for a given identifier.
     * The identifier can be specified using several formats:
     * <ul>
     * <li>FunctionLogicalName</li>
     * <li>ModuleSerialNumber.FunctionIdentifier</li>
     * <li>ModuleSerialNumber.FunctionLogicalName</li>
     * <li>ModuleLogicalName.FunctionIdentifier</li>
     * <li>ModuleLogicalName.FunctionLogicalName</li>
     * </ul>
     *
     * This function does not require that the serial port is online at the time
     * it is invoked. The returned object is nevertheless valid.
     * Use the method YSerialPort.isOnline() to test if the serial port is
     * indeed online at a given time. In case of ambiguity when looking for
     * a serial port by logical name, no error is notified: the first instance
     * found is returned. The search is performed first by hardware name,
     * then by logical name.
     *
     * If a call to this object's is_online() method returns FALSE although
     * you are certain that the matching device is plugged, make sure that you did
     * call registerHub() at application initialization time.
     *
     * @param func : a string that uniquely characterizes the serial port, for instance
     *         RS232MK1.serialPort.
     *
     * @return a YSerialPort object allowing you to drive the serial port.
     */
    public static YSerialPort FindSerialPort(String func)
    {
        YSerialPort obj;
        YAPIContext ctx = YAPI.GetYCtx(true);
        synchronized (ctx._functionCacheLock) {
            obj = (YSerialPort) YFunction._FindFromCache("SerialPort", func);
            if (obj == null) {
                obj = new YSerialPort(func);
                YFunction._AddToCache("SerialPort", func, obj);
            }
        }
        return obj;
    }

    /**
     * Retrieves a serial port for a given identifier in a YAPI context.
     * The identifier can be specified using several formats:
     * <ul>
     * <li>FunctionLogicalName</li>
     * <li>ModuleSerialNumber.FunctionIdentifier</li>
     * <li>ModuleSerialNumber.FunctionLogicalName</li>
     * <li>ModuleLogicalName.FunctionIdentifier</li>
     * <li>ModuleLogicalName.FunctionLogicalName</li>
     * </ul>
     *
     * This function does not require that the serial port is online at the time
     * it is invoked. The returned object is nevertheless valid.
     * Use the method YSerialPort.isOnline() to test if the serial port is
     * indeed online at a given time. In case of ambiguity when looking for
     * a serial port by logical name, no error is notified: the first instance
     * found is returned. The search is performed first by hardware name,
     * then by logical name.
     *
     * @param yctx : a YAPI context
     * @param func : a string that uniquely characterizes the serial port, for instance
     *         RS232MK1.serialPort.
     *
     * @return a YSerialPort object allowing you to drive the serial port.
     */
    public static YSerialPort FindSerialPortInContext(YAPIContext yctx,String func)
    {
        YSerialPort obj;
        synchronized (yctx._functionCacheLock) {
            obj = (YSerialPort) YFunction._FindFromCacheInContext(yctx, "SerialPort", func);
            if (obj == null) {
                obj = new YSerialPort(yctx, func);
                YFunction._AddToCache("SerialPort", func, obj);
            }
        }
        return obj;
    }

    /**
     * Registers the callback function that is invoked on every change of advertised value.
     * The callback is invoked only during the execution of ySleep or yHandleEvents.
     * This provides control over the time when the callback is triggered. For good responsiveness, remember to call
     * one of these two functions periodically. To unregister a callback, pass a null pointer as argument.
     *
     * @param callback : the callback function to call, or a null pointer. The callback function should take two
     *         arguments: the function object of which the value has changed, and the character string describing
     *         the new advertised value.
     *
     */
    public int registerValueCallback(UpdateCallback callback)
    {
        String val;
        if (callback != null) {
            YFunction._UpdateValueCallbackList(this, true);
        } else {
            YFunction._UpdateValueCallbackList(this, false);
        }
        _valueCallbackSerialPort = callback;
        // Immediately invoke value callback with current value
        if (callback != null && isOnline()) {
            val = _advertisedValue;
            if (!(val.equals(""))) {
                _invokeValueCallback(val);
            }
        }
        return 0;
    }

    @Override
    public int _invokeValueCallback(String value)
    {
        if (_valueCallbackSerialPort != null) {
            _valueCallbackSerialPort.yNewValue(this, value);
        } else {
            super._invokeValueCallback(value);
        }
        return 0;
    }

    public int sendCommand(String text) throws YAPI_Exception
    {
        return set_command(text);
    }

    /**
     * Reads a single line (or message) from the receive buffer, starting at current stream position.
     * This function is intended to be used when the serial port is configured for a message protocol,
     * such as 'Line' mode or frame protocols.
     *
     * If data at current stream position is not available anymore in the receive buffer,
     * the function returns the oldest available line and moves the stream position just after.
     * If no new full line is received, the function returns an empty line.
     *
     * @return a string with a single line of text
     *
     * @throws YAPI_Exception on error
     */
    public String readLine() throws YAPI_Exception
    {
        String url;
        byte[] msgbin;
        ArrayList<String> msgarr = new ArrayList<>();
        int msglen;
        String res;

        url = String.format(Locale.US, "rxmsg.json?pos=%d&len=1&maxw=1",_rxptr);
        msgbin = _download(url);
        msgarr = _json_get_array(msgbin);
        msglen = msgarr.size();
        if (msglen == 0) {
            return "";
        }
        // last element of array is the new position
        msglen = msglen - 1;
        _rxptr = YAPIContext._atoi(msgarr.get(msglen));
        if (msglen == 0) {
            return "";
        }
        res = _json_get_string((msgarr.get(0)).getBytes());
        return res;
    }

    /**
     * Searches for incoming messages in the serial port receive buffer matching a given pattern,
     * starting at current position. This function will only compare and return printable characters
     * in the message strings. Binary protocols are handled as hexadecimal strings.
     *
     * The search returns all messages matching the expression provided as argument in the buffer.
     * If no matching message is found, the search waits for one up to the specified maximum timeout
     * (in milliseconds).
     *
     * @param pattern : a limited regular expression describing the expected message format,
     *         or an empty string if all messages should be returned (no filtering).
     *         When using binary protocols, the format applies to the hexadecimal
     *         representation of the message.
     * @param maxWait : the maximum number of milliseconds to wait for a message if none is found
     *         in the receive buffer.
     *
     * @return an array of strings containing the messages found, if any.
     *         Binary messages are converted to hexadecimal representation.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<String> readMessages(String pattern,int maxWait) throws YAPI_Exception
    {
        String url;
        byte[] msgbin;
        ArrayList<String> msgarr = new ArrayList<>();
        int msglen;
        ArrayList<String> res = new ArrayList<>();
        int idx;

        url = String.format(Locale.US, "rxmsg.json?pos=%d&maxw=%d&pat=%s", _rxptr, maxWait,pattern);
        msgbin = _download(url);
        msgarr = _json_get_array(msgbin);
        msglen = msgarr.size();
        if (msglen == 0) {
            return res;
        }
        // last element of array is the new position
        msglen = msglen - 1;
        _rxptr = YAPIContext._atoi(msgarr.get(msglen));
        idx = 0;
        while (idx < msglen) {
            res.add(_json_get_string((msgarr.get(idx)).getBytes()));
            idx = idx + 1;
        }
        return res;
    }

    /**
     * Changes the current internal stream position to the specified value. This function
     * does not affect the device, it only changes the value stored in the API object
     * for the next read operations.
     *
     * @param absPos : the absolute position index for next read operations.
     *
     * @return nothing.
     */
    public int read_seek(int absPos)
    {
        _rxptr = absPos;
        return YAPI.SUCCESS;
    }

    /**
     * Returns the current absolute stream position pointer of the API object.
     *
     * @return the absolute position index for next read operations.
     */
    public int read_tell()
    {
        return _rxptr;
    }

    /**
     * Returns the number of bytes available to read in the input buffer starting from the
     * current absolute stream position pointer of the API object.
     *
     * @return the number of bytes available to read
     */
    public int read_avail() throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int res;

        buff = _download(String.format(Locale.US, "rxcnt.bin?pos=%d",_rxptr));
        bufflen = (buff).length - 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            bufflen = bufflen - 1;
        }
        res = YAPIContext._atoi((new String(buff)).substring(0, bufflen));
        return res;
    }

    /**
     * Sends a text line query to the serial port, and reads the reply, if any.
     * This function is intended to be used when the serial port is configured for 'Line' protocol.
     *
     * @param query : the line query to send (without CR/LF)
     * @param maxWait : the maximum number of milliseconds to wait for a reply.
     *
     * @return the next text line received after sending the text query, as a string.
     *         Additional lines can be obtained by calling readLine or readMessages.
     *
     * @throws YAPI_Exception on error
     */
    public String queryLine(String query,int maxWait) throws YAPI_Exception
    {
        String url;
        byte[] msgbin;
        ArrayList<String> msgarr = new ArrayList<>();
        int msglen;
        String res;

        url = String.format(Locale.US, "rxmsg.json?len=1&maxw=%d&cmd=!%s", maxWait,_escapeAttr(query));
        msgbin = _download(url);
        msgarr = _json_get_array(msgbin);
        msglen = msgarr.size();
        if (msglen == 0) {
            return "";
        }
        // last element of array is the new position
        msglen = msglen - 1;
        _rxptr = YAPIContext._atoi(msgarr.get(msglen));
        if (msglen == 0) {
            return "";
        }
        res = _json_get_string((msgarr.get(0)).getBytes());
        return res;
    }

    /**
     * Sends a binary message to the serial port, and reads the reply, if any.
     * This function is intended to be used when the serial port is configured for
     * Frame-based protocol.
     *
     * @param hexString : the message to send, coded in hexadecimal
     * @param maxWait : the maximum number of milliseconds to wait for a reply.
     *
     * @return the next frame received after sending the message, as a hex string.
     *         Additional frames can be obtained by calling readHex or readMessages.
     *
     * @throws YAPI_Exception on error
     */
    public String queryHex(String hexString,int maxWait) throws YAPI_Exception
    {
        String url;
        byte[] msgbin;
        ArrayList<String> msgarr = new ArrayList<>();
        int msglen;
        String res;

        url = String.format(Locale.US, "rxmsg.json?len=1&maxw=%d&cmd=$%s", maxWait,hexString);
        msgbin = _download(url);
        msgarr = _json_get_array(msgbin);
        msglen = msgarr.size();
        if (msglen == 0) {
            return "";
        }
        // last element of array is the new position
        msglen = msglen - 1;
        _rxptr = YAPIContext._atoi(msgarr.get(msglen));
        if (msglen == 0) {
            return "";
        }
        res = _json_get_string((msgarr.get(0)).getBytes());
        return res;
    }

    /**
     * Saves the job definition string (JSON data) into a job file.
     * The job file can be later enabled using selectJob().
     *
     * @param jobfile : name of the job file to save on the device filesystem
     * @param jsonDef : a string containing a JSON definition of the job
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int uploadJob(String jobfile,String jsonDef) throws YAPI_Exception
    {
        _upload(jobfile, (jsonDef).getBytes());
        return YAPI.SUCCESS;
    }

    /**
     * Load and start processing the specified job file. The file must have
     * been previously created using the user interface or uploaded on the
     * device filesystem using the uploadJob() function.
     *
     * @param jobfile : name of the job file (on the device filesystem)
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int selectJob(String jobfile) throws YAPI_Exception
    {
        return set_currentJob(jobfile);
    }

    /**
     * Clears the serial port buffer and resets counters to zero.
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int reset() throws YAPI_Exception
    {
        _rxptr = 0;
        _rxbuffptr = 0;
        _rxbuff = new byte[0];

        return sendCommand("Z");
    }

    /**
     * Sends a single byte to the serial port.
     *
     * @param code : the byte to send
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeByte(int code) throws YAPI_Exception
    {
        return sendCommand(String.format(Locale.US, "$%02X",code));
    }

    /**
     * Sends an ASCII string to the serial port, as is.
     *
     * @param text : the text string to send
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeStr(String text) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int idx;
        int ch;
        buff = (text).getBytes();
        bufflen = (buff).length;
        if (bufflen < 100) {
            // if string is pure text, we can send it as a simple command (faster)
            ch = 0x20;
            idx = 0;
            while ((idx < bufflen) && (ch != 0)) {
                ch = (buff[idx] & 0xff);
                if ((ch >= 0x20) && (ch < 0x7f)) {
                    idx = idx + 1;
                } else {
                    ch = 0;
                }
            }
            if (idx >= bufflen) {
                return sendCommand(String.format(Locale.US, "+%s",text));
            }
        }
        // send string using file upload
        return _upload("txdata", buff);
    }

    /**
     * Sends a binary buffer to the serial port, as is.
     *
     * @param buff : the binary buffer to send
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeBin(byte[] buff) throws YAPI_Exception
    {
        return _upload("txdata", buff);
    }

    /**
     * Sends a byte sequence (provided as a list of bytes) to the serial port.
     *
     * @param byteList : a list of byte codes
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeArray(ArrayList<Integer> byteList) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int idx;
        int hexb;
        int res;
        bufflen = byteList.size();
        buff = new byte[bufflen];
        idx = 0;
        while (idx < bufflen) {
            hexb = byteList.get(idx).intValue();
            buff[idx] = (byte)(hexb & 0xff);
            idx = idx + 1;
        }

        res = _upload("txdata", buff);
        return res;
    }

    /**
     * Sends a byte sequence (provided as a hexadecimal string) to the serial port.
     *
     * @param hexString : a string of hexadecimal byte codes
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeHex(String hexString) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int idx;
        int hexb;
        int res;
        bufflen = (hexString).length();
        if (bufflen < 100) {
            return sendCommand(String.format(Locale.US, "$%s",hexString));
        }
        bufflen = ((bufflen) >> (1));
        buff = new byte[bufflen];
        idx = 0;
        while (idx < bufflen) {
            hexb = Integer.valueOf((hexString).substring( 2 * idx,  2 * idx + 2),16);
            buff[idx] = (byte)(hexb & 0xff);
            idx = idx + 1;
        }

        res = _upload("txdata", buff);
        return res;
    }

    /**
     * Sends an ASCII string to the serial port, followed by a line break (CR LF).
     *
     * @param text : the text string to send
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeLine(String text) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int idx;
        int ch;
        buff = (String.format(Locale.US, "%s\r\n",text)).getBytes();
        bufflen = (buff).length-2;
        if (bufflen < 100) {
            // if string is pure text, we can send it as a simple command (faster)
            ch = 0x20;
            idx = 0;
            while ((idx < bufflen) && (ch != 0)) {
                ch = (buff[idx] & 0xff);
                if ((ch >= 0x20) && (ch < 0x7f)) {
                    idx = idx + 1;
                } else {
                    ch = 0;
                }
            }
            if (idx >= bufflen) {
                return sendCommand(String.format(Locale.US, "!%s",text));
            }
        }
        // send string using file upload
        return _upload("txdata", buff);
    }

    /**
     * Reads one byte from the receive buffer, starting at current stream position.
     * If data at current stream position is not available anymore in the receive buffer,
     * or if there is no data available yet, the function returns YAPI.NO_MORE_DATA.
     *
     * @return the next byte
     *
     * @throws YAPI_Exception on error
     */
    public int readByte() throws YAPI_Exception
    {
        int currpos;
        int reqlen;
        byte[] buff;
        int bufflen;
        int mult;
        int endpos;
        int res;
        // first check if we have the requested character in the look-ahead buffer
        bufflen = (_rxbuff).length;
        if ((_rxptr >= _rxbuffptr) && (_rxptr < _rxbuffptr+bufflen)) {
            res = (_rxbuff[_rxptr-_rxbuffptr] & 0xff);
            _rxptr = _rxptr + 1;
            return res;
        }
        // try to preload more than one byte to speed-up byte-per-byte access
        currpos = _rxptr;
        reqlen = 1024;
        buff = readBin(reqlen);
        bufflen = (buff).length;
        if (_rxptr == currpos+bufflen) {
            res = (buff[0] & 0xff);
            _rxptr = currpos+1;
            _rxbuffptr = currpos;
            _rxbuff = buff;
            return res;
        }
        // mixed bidirectional data, retry with a smaller block
        _rxptr = currpos;
        reqlen = 16;
        buff = readBin(reqlen);
        bufflen = (buff).length;
        if (_rxptr == currpos+bufflen) {
            res = (buff[0] & 0xff);
            _rxptr = currpos+1;
            _rxbuffptr = currpos;
            _rxbuff = buff;
            return res;
        }
        // still mixed, need to process character by character
        _rxptr = currpos;

        buff = _download(String.format(Locale.US, "rxdata.bin?pos=%d&len=1",_rxptr));
        bufflen = (buff).length - 1;
        endpos = 0;
        mult = 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            endpos = endpos + mult * ((buff[bufflen] & 0xff) - 48);
            mult = mult * 10;
            bufflen = bufflen - 1;
        }
        _rxptr = endpos;
        if (bufflen == 0) {
            return YAPI.NO_MORE_DATA;
        }
        res = (buff[0] & 0xff);
        return res;
    }

    /**
     * Reads data from the receive buffer as a string, starting at current stream position.
     * If data at current stream position is not available anymore in the receive buffer, the
     * function performs a short read.
     *
     * @param nChars : the maximum number of characters to read
     *
     * @return a string with receive buffer contents
     *
     * @throws YAPI_Exception on error
     */
    public String readStr(int nChars) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int mult;
        int endpos;
        String res;
        if (nChars > 65535) {
            nChars = 65535;
        }

        buff = _download(String.format(Locale.US, "rxdata.bin?pos=%d&len=%d", _rxptr,nChars));
        bufflen = (buff).length - 1;
        endpos = 0;
        mult = 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            endpos = endpos + mult * ((buff[bufflen] & 0xff) - 48);
            mult = mult * 10;
            bufflen = bufflen - 1;
        }
        _rxptr = endpos;
        res = (new String(buff)).substring(0, bufflen);
        return res;
    }

    /**
     * Reads data from the receive buffer as a binary buffer, starting at current stream position.
     * If data at current stream position is not available anymore in the receive buffer, the
     * function performs a short read.
     *
     * @param nChars : the maximum number of bytes to read
     *
     * @return a binary object with receive buffer contents
     *
     * @throws YAPI_Exception on error
     */
    public byte[] readBin(int nChars) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int mult;
        int endpos;
        int idx;
        byte[] res;
        if (nChars > 65535) {
            nChars = 65535;
        }

        buff = _download(String.format(Locale.US, "rxdata.bin?pos=%d&len=%d", _rxptr,nChars));
        bufflen = (buff).length - 1;
        endpos = 0;
        mult = 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            endpos = endpos + mult * ((buff[bufflen] & 0xff) - 48);
            mult = mult * 10;
            bufflen = bufflen - 1;
        }
        _rxptr = endpos;
        res = new byte[bufflen];
        idx = 0;
        while (idx < bufflen) {
            res[idx] = (byte)((buff[idx] & 0xff) & 0xff);
            idx = idx + 1;
        }
        return res;
    }

    /**
     * Reads data from the receive buffer as a list of bytes, starting at current stream position.
     * If data at current stream position is not available anymore in the receive buffer, the
     * function performs a short read.
     *
     * @param nChars : the maximum number of bytes to read
     *
     * @return a sequence of bytes with receive buffer contents
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> readArray(int nChars) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int mult;
        int endpos;
        int idx;
        int b;
        ArrayList<Integer> res = new ArrayList<>();
        if (nChars > 65535) {
            nChars = 65535;
        }

        buff = _download(String.format(Locale.US, "rxdata.bin?pos=%d&len=%d", _rxptr,nChars));
        bufflen = (buff).length - 1;
        endpos = 0;
        mult = 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            endpos = endpos + mult * ((buff[bufflen] & 0xff) - 48);
            mult = mult * 10;
            bufflen = bufflen - 1;
        }
        _rxptr = endpos;
        res.clear();
        idx = 0;
        while (idx < bufflen) {
            b = (buff[idx] & 0xff);
            res.add(b);
            idx = idx + 1;
        }
        return res;
    }

    /**
     * Reads data from the receive buffer as a hexadecimal string, starting at current stream position.
     * If data at current stream position is not available anymore in the receive buffer, the
     * function performs a short read.
     *
     * @param nBytes : the maximum number of bytes to read
     *
     * @return a string with receive buffer contents, encoded in hexadecimal
     *
     * @throws YAPI_Exception on error
     */
    public String readHex(int nBytes) throws YAPI_Exception
    {
        byte[] buff;
        int bufflen;
        int mult;
        int endpos;
        int ofs;
        String res;
        if (nBytes > 65535) {
            nBytes = 65535;
        }

        buff = _download(String.format(Locale.US, "rxdata.bin?pos=%d&len=%d", _rxptr,nBytes));
        bufflen = (buff).length - 1;
        endpos = 0;
        mult = 1;
        while ((bufflen > 0) && ((buff[bufflen] & 0xff) != 64)) {
            endpos = endpos + mult * ((buff[bufflen] & 0xff) - 48);
            mult = mult * 10;
            bufflen = bufflen - 1;
        }
        _rxptr = endpos;
        res = "";
        ofs = 0;
        while (ofs + 3 < bufflen) {
            res = String.format(Locale.US, "%s%02X%02X%02X%02X", res, (buff[ofs] & 0xff), (buff[ofs + 1] & 0xff), (buff[ofs + 2] & 0xff),(buff[ofs + 3] & 0xff));
            ofs = ofs + 4;
        }
        while (ofs < bufflen) {
            res = String.format(Locale.US, "%s%02X", res,(buff[ofs] & 0xff));
            ofs = ofs + 1;
        }
        return res;
    }

    /**
     * Manually sets the state of the RTS line. This function has no effect when
     * hardware handshake is enabled, as the RTS line is driven automatically.
     *
     * @param val : 1 to turn RTS on, 0 to turn RTS off
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int set_RTS(int val) throws YAPI_Exception
    {
        return sendCommand(String.format(Locale.US, "R%d",val));
    }

    /**
     * Reads the level of the CTS line. The CTS line is usually driven by
     * the RTS signal of the connected serial device.
     *
     * @return 1 if the CTS line is high, 0 if the CTS line is low.
     *
     * @throws YAPI_Exception on error
     */
    public int get_CTS() throws YAPI_Exception
    {
        byte[] buff;
        int res;

        buff = _download("cts.txt");
        //noinspection DoubleNegation
        if (!((buff).length == 1)) { throw new YAPI_Exception( YAPI.IO_ERROR,  "invalid CTS reply");}
        res = (buff[0] & 0xff) - 48;
        return res;
    }

    /**
     * Retrieves messages (both direction) in the serial port buffer, starting at current position.
     * This function will only compare and return printable characters in the message strings.
     * Binary protocols are handled as hexadecimal strings.
     *
     * If no message is found, the search waits for one up to the specified maximum timeout
     * (in milliseconds).
     *
     * @param maxWait : the maximum number of milliseconds to wait for a message if none is found
     *         in the receive buffer.
     *
     * @return an array of YSnoopingRecord objects containing the messages found, if any.
     *         Binary messages are converted to hexadecimal representation.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<YSnoopingRecord> snoopMessages(int maxWait) throws YAPI_Exception
    {
        String url;
        byte[] msgbin;
        ArrayList<String> msgarr = new ArrayList<>();
        int msglen;
        ArrayList<YSnoopingRecord> res = new ArrayList<>();
        int idx;

        url = String.format(Locale.US, "rxmsg.json?pos=%d&maxw=%d&t=0", _rxptr,maxWait);
        msgbin = _download(url);
        msgarr = _json_get_array(msgbin);
        msglen = msgarr.size();
        if (msglen == 0) {
            return res;
        }
        // last element of array is the new position
        msglen = msglen - 1;
        _rxptr = YAPIContext._atoi(msgarr.get(msglen));
        idx = 0;
        while (idx < msglen) {
            res.add(new YSnoopingRecord(msgarr.get(idx)));
            idx = idx + 1;
        }
        return res;
    }

    /**
     * Sends an ASCII string to the serial port, preceeded with an STX code and
     * followed by an ETX code.
     *
     * @param text : the text string to send
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeStxEtx(String text) throws YAPI_Exception
    {
        byte[] buff;
        buff = (String.format(Locale.US, "%c%s%c", 2, text,3)).getBytes();
        // send string using file upload
        return _upload("txdata", buff);
    }

    /**
     * Sends a MODBUS message (provided as a hexadecimal string) to the serial port.
     * The message must start with the slave address. The MODBUS CRC/LRC is
     * automatically added by the function. This function does not wait for a reply.
     *
     * @param hexString : a hexadecimal message string, including device address but no CRC/LRC
     *
     * @return YAPI.SUCCESS if the call succeeds.
     *
     * @throws YAPI_Exception on error
     */
    public int writeMODBUS(String hexString) throws YAPI_Exception
    {
        return sendCommand(String.format(Locale.US, ":%s",hexString));
    }

    /**
     * Sends a message to a specified MODBUS slave connected to the serial port, and reads the
     * reply, if any. The message is the PDU, provided as a vector of bytes.
     *
     * @param slaveNo : the address of the slave MODBUS device to query
     * @param pduBytes : the message to send (PDU), as a vector of bytes. The first byte of the
     *         PDU is the MODBUS function code.
     *
     * @return the received reply, as a vector of bytes.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> queryMODBUS(int slaveNo,ArrayList<Integer> pduBytes) throws YAPI_Exception
    {
        int funCode;
        int nib;
        int i;
        String cmd;
        String url;
        String pat;
        byte[] msgs;
        ArrayList<String> reps = new ArrayList<>();
        String rep;
        ArrayList<Integer> res = new ArrayList<>();
        int replen;
        int hexb;
        funCode = pduBytes.get(0).intValue();
        nib = ((funCode) >> (4));
        pat = String.format(Locale.US, "%02X[%X%X]%X.*", slaveNo, nib, (nib+8),((funCode) & (15)));
        cmd = String.format(Locale.US, "%02X%02X", slaveNo,funCode);
        i = 1;
        while (i < pduBytes.size()) {
            cmd = String.format(Locale.US, "%s%02X", cmd,((pduBytes.get(i).intValue()) & (0xff)));
            i = i + 1;
        }

        url = String.format(Locale.US, "rxmsg.json?cmd=:%s&pat=:%s", cmd,pat);
        msgs = _download(url);
        reps = _json_get_array(msgs);
        //noinspection DoubleNegation
        if (!(reps.size() > 1)) { throw new YAPI_Exception( YAPI.IO_ERROR,  "no reply from MODBUS slave");}
        if (reps.size() > 1) {
            rep = _json_get_string((reps.get(0)).getBytes());
            replen = (((rep).length() - 3) >> (1));
            i = 0;
            while (i < replen) {
                hexb = Integer.valueOf((rep).substring(2 * i + 3, 2 * i + 3 + 2),16);
                res.add(hexb);
                i = i + 1;
            }
            if (res.get(0).intValue() != funCode) {
                i = res.get(1).intValue();
                //noinspection DoubleNegation
                if (!(i > 1)) { throw new YAPI_Exception( YAPI.NOT_SUPPORTED,  "MODBUS error: unsupported function code");}
                //noinspection DoubleNegation
                if (!(i > 2)) { throw new YAPI_Exception( YAPI.INVALID_ARGUMENT,  "MODBUS error: illegal data address");}
                //noinspection DoubleNegation
                if (!(i > 3)) { throw new YAPI_Exception( YAPI.INVALID_ARGUMENT,  "MODBUS error: illegal data value");}
                //noinspection DoubleNegation
                if (!(i > 4)) { throw new YAPI_Exception( YAPI.INVALID_ARGUMENT,  "MODBUS error: failed to execute function");}
            }
        }
        return res;
    }

    /**
     * Reads one or more contiguous internal bits (or coil status) from a MODBUS serial device.
     * This method uses the MODBUS function code 0x01 (Read Coils).
     *
     * @param slaveNo : the address of the slave MODBUS device to query
     * @param pduAddr : the relative address of the first bit/coil to read (zero-based)
     * @param nBits : the number of bits/coils to read
     *
     * @return a vector of integers, each corresponding to one bit.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> modbusReadBits(int slaveNo,int pduAddr,int nBits) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        ArrayList<Integer> res = new ArrayList<>();
        int bitpos;
        int idx;
        int val;
        int mask;
        pdu.add(0x01);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nBits) >> (8)));
        pdu.add(((nBits) & (0xff)));

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        bitpos = 0;
        idx = 2;
        val = reply.get(idx).intValue();
        mask = 1;
        while (bitpos < nBits) {
            if (((val) & (mask)) == 0) {
                res.add(0);
            } else {
                res.add(1);
            }
            bitpos = bitpos + 1;
            if (mask == 0x80) {
                idx = idx + 1;
                val = reply.get(idx).intValue();
                mask = 1;
            } else {
                mask = ((mask) << (1));
            }
        }
        return res;
    }

    /**
     * Reads one or more contiguous input bits (or discrete inputs) from a MODBUS serial device.
     * This method uses the MODBUS function code 0x02 (Read Discrete Inputs).
     *
     * @param slaveNo : the address of the slave MODBUS device to query
     * @param pduAddr : the relative address of the first bit/input to read (zero-based)
     * @param nBits : the number of bits/inputs to read
     *
     * @return a vector of integers, each corresponding to one bit.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> modbusReadInputBits(int slaveNo,int pduAddr,int nBits) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        ArrayList<Integer> res = new ArrayList<>();
        int bitpos;
        int idx;
        int val;
        int mask;
        pdu.add(0x02);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nBits) >> (8)));
        pdu.add(((nBits) & (0xff)));

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        bitpos = 0;
        idx = 2;
        val = reply.get(idx).intValue();
        mask = 1;
        while (bitpos < nBits) {
            if (((val) & (mask)) == 0) {
                res.add(0);
            } else {
                res.add(1);
            }
            bitpos = bitpos + 1;
            if (mask == 0x80) {
                idx = idx + 1;
                val = reply.get(idx).intValue();
                mask = 1;
            } else {
                mask = ((mask) << (1));
            }
        }
        return res;
    }

    /**
     * Reads one or more contiguous internal registers (holding registers) from a MODBUS serial device.
     * This method uses the MODBUS function code 0x03 (Read Holding Registers).
     *
     * @param slaveNo : the address of the slave MODBUS device to query
     * @param pduAddr : the relative address of the first holding register to read (zero-based)
     * @param nWords : the number of holding registers to read
     *
     * @return a vector of integers, each corresponding to one 16-bit register value.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> modbusReadRegisters(int slaveNo,int pduAddr,int nWords) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        ArrayList<Integer> res = new ArrayList<>();
        int regpos;
        int idx;
        int val;
        pdu.add(0x03);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nWords) >> (8)));
        pdu.add(((nWords) & (0xff)));

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        regpos = 0;
        idx = 2;
        while (regpos < nWords) {
            val = ((reply.get(idx).intValue()) << (8));
            idx = idx + 1;
            val = val + reply.get(idx).intValue();
            idx = idx + 1;
            res.add(val);
            regpos = regpos + 1;
        }
        return res;
    }

    /**
     * Reads one or more contiguous input registers (read-only registers) from a MODBUS serial device.
     * This method uses the MODBUS function code 0x04 (Read Input Registers).
     *
     * @param slaveNo : the address of the slave MODBUS device to query
     * @param pduAddr : the relative address of the first input register to read (zero-based)
     * @param nWords : the number of input registers to read
     *
     * @return a vector of integers, each corresponding to one 16-bit input value.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> modbusReadInputRegisters(int slaveNo,int pduAddr,int nWords) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        ArrayList<Integer> res = new ArrayList<>();
        int regpos;
        int idx;
        int val;
        pdu.add(0x04);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nWords) >> (8)));
        pdu.add(((nWords) & (0xff)));

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        regpos = 0;
        idx = 2;
        while (regpos < nWords) {
            val = ((reply.get(idx).intValue()) << (8));
            idx = idx + 1;
            val = val + reply.get(idx).intValue();
            idx = idx + 1;
            res.add(val);
            regpos = regpos + 1;
        }
        return res;
    }

    /**
     * Sets a single internal bit (or coil) on a MODBUS serial device.
     * This method uses the MODBUS function code 0x05 (Write Single Coil).
     *
     * @param slaveNo : the address of the slave MODBUS device to drive
     * @param pduAddr : the relative address of the bit/coil to set (zero-based)
     * @param value : the value to set (0 for OFF state, non-zero for ON state)
     *
     * @return the number of bits/coils affected on the device (1)
     *
     * @throws YAPI_Exception on error
     */
    public int modbusWriteBit(int slaveNo,int pduAddr,int value) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        int res;
        res = 0;
        if (value != 0) {
            value = 0xff;
        }
        pdu.add(0x05);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(value);
        pdu.add(0x00);

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        res = 1;
        return res;
    }

    /**
     * Sets several contiguous internal bits (or coils) on a MODBUS serial device.
     * This method uses the MODBUS function code 0x0f (Write Multiple Coils).
     *
     * @param slaveNo : the address of the slave MODBUS device to drive
     * @param pduAddr : the relative address of the first bit/coil to set (zero-based)
     * @param bits : the vector of bits to be set (one integer per bit)
     *
     * @return the number of bits/coils affected on the device
     *
     * @throws YAPI_Exception on error
     */
    public int modbusWriteBits(int slaveNo,int pduAddr,ArrayList<Integer> bits) throws YAPI_Exception
    {
        int nBits;
        int nBytes;
        int bitpos;
        int val;
        int mask;
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        int res;
        res = 0;
        nBits = bits.size();
        nBytes = (((nBits + 7)) >> (3));
        pdu.add(0x0f);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nBits) >> (8)));
        pdu.add(((nBits) & (0xff)));
        pdu.add(nBytes);
        bitpos = 0;
        val = 0;
        mask = 1;
        while (bitpos < nBits) {
            if (bits.get(bitpos).intValue() != 0) {
                val = ((val) | (mask));
            }
            bitpos = bitpos + 1;
            if (mask == 0x80) {
                pdu.add(val);
                val = 0;
                mask = 1;
            } else {
                mask = ((mask) << (1));
            }
        }
        if (mask != 1) {
            pdu.add(val);
        }

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        res = ((reply.get(3).intValue()) << (8));
        res = res + reply.get(4).intValue();
        return res;
    }

    /**
     * Sets a single internal register (or holding register) on a MODBUS serial device.
     * This method uses the MODBUS function code 0x06 (Write Single Register).
     *
     * @param slaveNo : the address of the slave MODBUS device to drive
     * @param pduAddr : the relative address of the register to set (zero-based)
     * @param value : the 16 bit value to set
     *
     * @return the number of registers affected on the device (1)
     *
     * @throws YAPI_Exception on error
     */
    public int modbusWriteRegister(int slaveNo,int pduAddr,int value) throws YAPI_Exception
    {
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        int res;
        res = 0;
        pdu.add(0x06);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((value) >> (8)));
        pdu.add(((value) & (0xff)));

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        res = 1;
        return res;
    }

    /**
     * Sets several contiguous internal registers (or holding registers) on a MODBUS serial device.
     * This method uses the MODBUS function code 0x10 (Write Multiple Registers).
     *
     * @param slaveNo : the address of the slave MODBUS device to drive
     * @param pduAddr : the relative address of the first internal register to set (zero-based)
     * @param values : the vector of 16 bit values to set
     *
     * @return the number of registers affected on the device
     *
     * @throws YAPI_Exception on error
     */
    public int modbusWriteRegisters(int slaveNo,int pduAddr,ArrayList<Integer> values) throws YAPI_Exception
    {
        int nWords;
        int nBytes;
        int regpos;
        int val;
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        int res;
        res = 0;
        nWords = values.size();
        nBytes = 2 * nWords;
        pdu.add(0x10);
        pdu.add(((pduAddr) >> (8)));
        pdu.add(((pduAddr) & (0xff)));
        pdu.add(((nWords) >> (8)));
        pdu.add(((nWords) & (0xff)));
        pdu.add(nBytes);
        regpos = 0;
        while (regpos < nWords) {
            val = values.get(regpos).intValue();
            pdu.add(((val) >> (8)));
            pdu.add(((val) & (0xff)));
            regpos = regpos + 1;
        }

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        res = ((reply.get(3).intValue()) << (8));
        res = res + reply.get(4).intValue();
        return res;
    }

    /**
     * Sets several contiguous internal registers (holding registers) on a MODBUS serial device,
     * then performs a contiguous read of a set of (possibly different) internal registers.
     * This method uses the MODBUS function code 0x17 (Read/Write Multiple Registers).
     *
     * @param slaveNo : the address of the slave MODBUS device to drive
     * @param pduWriteAddr : the relative address of the first internal register to set (zero-based)
     * @param values : the vector of 16 bit values to set
     * @param pduReadAddr : the relative address of the first internal register to read (zero-based)
     * @param nReadWords : the number of 16 bit values to read
     *
     * @return a vector of integers, each corresponding to one 16-bit register value read.
     *
     * @throws YAPI_Exception on error
     */
    public ArrayList<Integer> modbusWriteAndReadRegisters(int slaveNo,int pduWriteAddr,ArrayList<Integer> values,int pduReadAddr,int nReadWords) throws YAPI_Exception
    {
        int nWriteWords;
        int nBytes;
        int regpos;
        int val;
        int idx;
        ArrayList<Integer> pdu = new ArrayList<>();
        ArrayList<Integer> reply = new ArrayList<>();
        ArrayList<Integer> res = new ArrayList<>();
        nWriteWords = values.size();
        nBytes = 2 * nWriteWords;
        pdu.add(0x17);
        pdu.add(((pduReadAddr) >> (8)));
        pdu.add(((pduReadAddr) & (0xff)));
        pdu.add(((nReadWords) >> (8)));
        pdu.add(((nReadWords) & (0xff)));
        pdu.add(((pduWriteAddr) >> (8)));
        pdu.add(((pduWriteAddr) & (0xff)));
        pdu.add(((nWriteWords) >> (8)));
        pdu.add(((nWriteWords) & (0xff)));
        pdu.add(nBytes);
        regpos = 0;
        while (regpos < nWriteWords) {
            val = values.get(regpos).intValue();
            pdu.add(((val) >> (8)));
            pdu.add(((val) & (0xff)));
            regpos = regpos + 1;
        }

        reply = queryMODBUS(slaveNo, pdu);
        if (reply.size() == 0) {
            return res;
        }
        if (reply.get(0).intValue() != pdu.get(0).intValue()) {
            return res;
        }
        regpos = 0;
        idx = 2;
        while (regpos < nReadWords) {
            val = ((reply.get(idx).intValue()) << (8));
            idx = idx + 1;
            val = val + reply.get(idx).intValue();
            idx = idx + 1;
            res.add(val);
            regpos = regpos + 1;
        }
        return res;
    }

    /**
     * Continues the enumeration of serial ports started using yFirstSerialPort().
     * Caution: You can't make any assumption about the returned serial ports order.
     * If you want to find a specific a serial port, use SerialPort.findSerialPort()
     * and a hardwareID or a logical name.
     *
     * @return a pointer to a YSerialPort object, corresponding to
     *         a serial port currently online, or a null pointer
     *         if there are no more serial ports to enumerate.
     */
    public YSerialPort nextSerialPort()
    {
        String next_hwid;
        try {
            String hwid = _yapi._yHash.resolveHwID(_className, _func);
            next_hwid = _yapi._yHash.getNextHardwareId(_className, hwid);
        } catch (YAPI_Exception ignored) {
            next_hwid = null;
        }
        if(next_hwid == null) return null;
        return FindSerialPortInContext(_yapi, next_hwid);
    }

    /**
     * Starts the enumeration of serial ports currently accessible.
     * Use the method YSerialPort.nextSerialPort() to iterate on
     * next serial ports.
     *
     * @return a pointer to a YSerialPort object, corresponding to
     *         the first serial port currently online, or a null pointer
     *         if there are none.
     */
    public static YSerialPort FirstSerialPort()
    {
        YAPIContext yctx = YAPI.GetYCtx(false);
        if (yctx == null)  return null;
        String next_hwid = yctx._yHash.getFirstHardwareId("SerialPort");
        if (next_hwid == null)  return null;
        return FindSerialPortInContext(yctx, next_hwid);
    }

    /**
     * Starts the enumeration of serial ports currently accessible.
     * Use the method YSerialPort.nextSerialPort() to iterate on
     * next serial ports.
     *
     * @param yctx : a YAPI context.
     *
     * @return a pointer to a YSerialPort object, corresponding to
     *         the first serial port currently online, or a null pointer
     *         if there are none.
     */
    public static YSerialPort FirstSerialPortInContext(YAPIContext yctx)
    {
        String next_hwid = yctx._yHash.getFirstHardwareId("SerialPort");
        if (next_hwid == null)  return null;
        return FindSerialPortInContext(yctx, next_hwid);
    }

    //--- (end of generated code: YSerialPort implementation)
}

