Examples - RS485 Network - Slave (Advanced)

//-----------------------------------------------------------------------------
// Slave.vpl, created 2003-04-07 15:44
//
// This is a small demonstration program, that shows how to communicate using
// the serial routines (via RS485) in the RTCU devices. Two projects are involved,
// Master and Slave.
//
//
// Format:
// To Slave FROM Master:
// <STX> <SRC> <DST> <DO Data-LSB> <DO Data-MSB>
//                   <AO-1-LSB> <AO-1-MSB>
//                   <AO-2-LSB> <AO-2-MSB>
//                   <AO-3-LSB> <AO-3-MSB>
//                   <AO-4-LSB> <AO-4-MSB> <ETX>
//
//
// To Master FROM Slave:
// <STX> <SRC> <DST> <DI Data-LSB> <DI Data-MSB>
//                   <AI-1-LSB> <AI-1-MSB>
//                   <AI-2-LSB> <AI-2-MSB>
//                   <AI-3-LSB> <AI-3-MSB>
//                   <AI-4-LSB> <AI-4-MSB> <ETX>
//
//
// STX = 0xFF
// ETX = 0xFE
// STUFF = 0x1B
// <DO-Data-LSB>/<DO-Data-MSB> = New status for digital outputs
// <AO-n-LSB>/<AO-n-MSB> = New data for analog output n
//
// <DI-Data-LSB>/<DI-Data-MSB> = New status for digital inputs
// <AI-n-LSB>/<AI-n-MSB> = New data for analog input n
//
//-----------------------------------------------------------------------------
INCLUDE rtcu.inc
 
// Input variables that can be configured via the configuration dialog (These are global)
VAR_INPUT
  SerialPort : SINT;           | Serial port to communicate on (0=service port, 1=port 2)
  Din   : ARRAY[1..12] OF BOOL; | Digital inputs
  Ain   : ARRAY[1..4] OF INT; | Analog inputs
  NodeSW : ARRAY[1..3] OF BOOL; | Dipswitches for node id (binary, SW1=LSB, SW3=MSB)
END_VAR;
 
// Output variables that can be configured via the configuration dialog (These are global)
VAR_OUTPUT
  Dout : ARRAY[1..12] OF BOOL; | Digital outputs
  Aout : ARRAY[1..4] OF INT;   | Analog outputs
  RXLed : BOOL;                 | changes state after each receive (with correct nodeid)
END_VAR;
 
//----------------------------------------------------------------------------
// Misc. helper functions
// Pack/Unpack INT and DINT's from an array of SINT
//----------------------------------------------------------------------------
FUNCTION getINT:INT;
VAR_INPUT
  adr : ptr;
END_VAR;
  memcpy(dst:=ADDR(getInt),src:=adr,len:=SIZEOF(getINT));
END_FUNCTION;
 
FUNCTION setINT;
VAR_INPUT
  adr : ptr;
  v : INT;
END_VAR;
  memcpy(dst:=adr,src:=ADDR(v),len:=SIZEOF(v));
END_FUNCTION;
//----------------------------------------------------------------------------

PROGRAM Slave;
VAR
  MyNodeID : SINT;
  RX     : serFrameReceiver;
  Len     : SINT;
  RxBuffer : ARRAY[0..63] of SINT;
  TxBuffer : ARRAY[0..63] of SINT;
  Index   : SINT; // Temporary variable/counter
END_VAR;
 
MyNodeID:=SINT(NodeSW[3])*4 + SINT(NodeSW[2])*2 + SINT(NodeSW[1]);
DebugFmt(message:="Slave running, nodeid=\1", v1:=MyNodeID);
 
serOpen(Port:=SerialPort, Baud:=57600, bit:=8, Parity:=0, RS485:=TRUE);
RX(port:=SerialPort, enable:=TRUE, frame:=ADDR(rxbuffer), maxsize:=SINT(SIZEOF(rxbuffer)), stuffch:=16#10, sof:=16#02, eof:=16#03);
 
BEGIN
  RX();
  // If a frame is received
  IF RX.Ready THEN
    // and it is for this node...
    IF (MyNodeID = RXBuffer[1] AND RX.Size=12) THEN
        // Set the digital outputs
        FOR index:=0 TO 7 DO
          DOut[index+1]:=(RXBuffer[2] AND shl8(in:=1, n:=index)) <> 0;
        END_FOR;
        FOR index:=0 TO 3 DO
          DOut[index+9]:=(RXBuffer[3] AND shl8(in:=1, n:=index)) <> 0;
        END_FOR;
        // Set the analog outputs
        AOut[1]:=getINT(adr:=ADDR(RXBuffer[4]));
        AOut[2]:=getINT(adr:=ADDR(RXBuffer[6]));
        AOut[3]:=getINT(adr:=ADDR(RXBuffer[8]));
        AOut[4]:=getINT(adr:=ADDR(RXBuffer[10]));
        RXLed:=NOT RXLed;
 
        // Build response
        TXBuffer[0]:=MyNodeID;
        TXBuffer[1]:=RXBuffer[0];
        // Build 2 bytes with status of digital inputs
        TXBuffer[2]:=0;
        TXBuffer[3]:=0;
        FOR index:=0 TO 7 DO
          IF DIn[index+1] THEN
              TXBuffer[2]:=TXBuffer[2] OR shl8(in:=1, n:=index);
          END_IF;
        END_FOR;
        FOR index:=0 TO 3 DO
          IF DIn[index+9] THEN
              TXBuffer[3]:=TXBuffer[3] OR shl8(in:=1, n:=index);
          END_IF;
        END_FOR;
        // Set analog values in response
        setInt(adr:=ADDR(TXBuffer[4]), v:=Ain[1]);
        setInt(adr:=ADDR(TXBuffer[6]), v:=Ain[2]);
        setInt(adr:=ADDR(TXBuffer[8]), v:=Ain[3]);
        setInt(adr:=ADDR(TXBuffer[10]),v:=Ain[4]);
        // Send the response
        serSendData(port:=SerialPort, data:=ADDR(TXBuffer), size:=12, stuffch:=16#10, sof:=16#02, eof:=16#03);
    ELSE
        DebugMsg(message:="Message not for this node !");
    END_IF;
     serFrameReceiveDone(port:=SerialPort);
  END_IF;
END;
 
END_PROGRAM;