ScriptAuthor "Deutschmann Automation GmbH" 
ScriptName "Modbus/TCP-Test"
ScriptVersion "V 1.0" 

SetErrorHandler ( :Address ) ;
SetSystemErrorHandler ( :Address ) ;


// This script realized the Modbus-RTU-function
// described in UNIGATE Manual 

// Bufferlength must be max. Fieldbus-Length
// For this example = 32 Byte
Var BusInput  : BUFFER[32] ; // 32=max.Fieldbus-Length
Var BusOutput : BUFFER[32] ; // 32=max.Fieldbus-Length
Var wBusInputLen:  Word ;
Var wBusOutputLen: Word ;
Var bBusInputLen:  byte ;
Var bBusOutputLen: byte ;
Var Timeout_ms:   Word ;
Var ModbusRxLen:  Word ;
Var bModbusRxLen:  byte ;
Var ReturnCode:   Byte ;
Var NoError:      Byte ;
Var Const0:       Word;  MoveConst( Const0, 0);
var channel: Byte;
var pk1: Word;
var bDestination:byte;

MoveConst (Timeout_ms , 0) ; // No timeout-check
MoveConst (NoError, 0) ;     // Returncode 0 = No Error

// Init serial port
Set ( Baudrate , 19200 ) ;
Set ( Databits , 8 ) ; 
Set ( Startbits , 1 ) ; 
Set ( Stopbits , 1 ) ;
Set ( Parity , even ) ;

Set ( ModbusRTUTimeout , 10000 ) ;  // 250ms
Set ( RS_State_LED , RedGreenFlashing ) ; 

// Start Bus and wait until running



// Source-Ports und Destination-Ports fuer die 4 Kanaele festlegen
// ---------------------------------------------------------------


MoveConst(pk1,0x01F6);
MoveConst (channel, 0 );
// InitFastEthernet ( channel,TCPIP_Server,pk1,pk1,ipa) ;
InitFastEthernet ( channel,ModbusTCP); //   ,pk1,pk1,ipa) ;


BusStart ;
Wait ( Bus_Active ) ; 
Set ( RS_State_LED , GreenFlashing ) ; 

:WaitNewBusData ;

Set ( CommunicationChannel , 0 ) ;


// Wait without timeout for changed Busdata
// Get ( BusDataChanged , v1 ) ;
:START;
Get ( AvailableBusData , wBusInputLen ) ;
if wBusInputLen greater Const0 then :GETD else :START ;

// WaitBusDataChanged ( Timeout_ms , BusInputLen ) ;
:GETD;
ReadBus ( BusInput[0] , wBusInputLen ) ;

// Received Busdata will be send by Modbus
// Then wait for Modbus answer
ExchangeModbusRTUMaster ( BusInput[0], BusOutput[0], bModbusRxLen ) ;

// Check Returncode for Modbus-Error
Get ( ErrorCode , ReturnCode ) ; 

if ReturnCode equal NoError then :CopyModbusDataToBus else :ModbusError ;

:CopyModbusDataToBus ;
Set ( Errorcode , 0 ) ; // Clear Error-LEDs
// Send received Modbus-Data to fieldbus
Convert ( bModbusRxLen , Byte , ModbusRxLen , Word ) ;

WriteBus ( BusOutput[0] , ModbusRxLen ) ;
Set ( RS_State_LED , StaticGreen ) ; 
jump :WaitNewBusData ; 

:ModbusError ;
// RS-LED static red, Yellow-LED blinking with "10"  
Set ( Errorcode , 10 ) ; 
jump :WaitNewBusData ;

:Address;
Get ( errorCode , bDestination ) ;
// TBD
 stop;
return;