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Main   FieldTalk Modbus    Overview   Documentation   Evaluation   Testimonials   Platforms    Windows   Linux   QNX   Commercial Unix   Java   Delphi   Product Details    Visit our Webstore   Features   Requirements   Licensing   Support Plans   Documentation    General Description   Module Description   Class Hierarchy   Classes   Functions & Members   Installation   Linking   Modbus Background   Examples   Integration		Server Functions common to all Protocol Flavours Detailed Description The FieldTalk Modbus Slave Protocol Library's server engine implements the most commonly used Modbus data functions as well as some control functions. The functions to perform PLC program download and other device specific functions are outside the scope of this library. All functions of conformance Class 0 and Class 1 have been implemented. In addition the most frequent used functions of conformance Class 2 have been implemented. The following table lists the functions supported by the slave: Function Code Current Terminology Classic Terminology Conformance Class 0 3 (03 hex) Read Multiple Registers Read Holding Registers 16 (10 hex) Write Multiple Registers Preset Multiple Registers Conformance Class 1 1 (01 hex) Read Coils Read Coil Status 2 (02 hex) Read Inputs Discretes Read Input Status 4 (04 hex) Read Input Registers Read Input Registers 5 (05 hex) Write Coil Force Single Coil 6 (06 hex) Write Single Register Preset Single Register 7 (07 hex) Read Exception Status Read Exception Status Conformance Class 2 15 (0F hex) Force Multiple Coils Force Multiple Coils 22 (16 hex) Mask Write Register Mask Write Register 23 (17 hex) Read/Write Registers Read/Write Registers Server Management Functions virtual int  MbusSlaveServer::serverLoop ()=0   Modbus slave server loop. virtual void  MbusSlaveServer::shutdownServer ()   Shuts down the Modbus Server. virtual int  MbusSlaveServer::isStarted ()=0   Returns wether server has been started up. Protocol Configuration long  MbusSlaveServer::setTimeout (long timeOut)   Configures master time-out supervision. long  MbusSlaveServer::getTimeout ()   Returns the master time-out supervision value. Transmission Statistic Functions unsigned long  MbusSlaveServer::getTotalCounter ()   Returns how often a message transfer has been executed. void  MbusSlaveServer::resetTotalCounter ()   Resets total message transfer counter. unsigned long  MbusSlaveServer::getSuccessCounter ()   Returns how often a message transfer was successful. void  MbusSlaveServer::resetSuccessCounter ()   Resets successful message transfer counter. Utility Functions char *  MbusSlaveServer::getPackageVersion ()   Returns the package version number. Function Documentation virtual int serverLoop (   )  [pure virtual, inherited]   Modbus slave server loop. This server loop must be called continuously. It must not be blocked. The server has to be started before calling the serverLoop() method. In most cases the server loop is executed in an endless loop: while (1) { mbusProtocol.serverLoop(); doOtherStuff(); } Returns: FTALK_SUCCESS on success or error code. See Protocol Errors and Exceptions for a list of error codes. Implemented in MbusRtuSlaveProtocol, MbusAsciiSlaveProtocol, and MbusTcpSlaveProtocol. long setTimeout (  long  timeOut  )  [inherited]   Configures master time-out supervision. The slave is monitoring whether a master is actually polling it or not. This function sets the master poll time-out to the specified value. A value of 0 disables the time-out, which stops time-out notifications being sent to the Data Provider. Remarks: The time-out value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution. Parameters: timeOut  Timeout value in ms (Range: 0 - 100000), 0 disables time-out Return values: FTALK_SUCCESS  Success FTALK_ILLEGAL_ARGUMENT_ERROR  Argument out of range unsigned long getTotalCounter (   )  [inherited]   Returns how often a message transfer has been executed. Returns: Counter value char * getPackageVersion (   )  [static, inherited]   Returns the package version number. Returns: Package version string long getTimeout (   )  [inherited]   Returns the master time-out supervision value. Remarks: The time-out value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution. Returns: Timeout value in ms unsigned long getSuccessCounter (   )  [inherited]   Returns how often a message transfer was successful. Returns: Counter value void shutdownServer (   )  [virtual, inherited]   Shuts down the Modbus Server. This function also closes any associated serial ports or sockets. Reimplemented in MbusSerialSlaveProtocol, and MbusTcpSlaveProtocol. virtual int isStarted (   )  [pure virtual, inherited]   Returns wether server has been started up. Return values: true  = started false  = shutdown Implemented in MbusSerialSlaveProtocol, and MbusTcpSlaveProtocol.

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