Merging release 2.0 branch with CVS trunk

r2601 | ffr | 2008-05-30 10:26:57 +1000 (Fri, 30 May 2008) | 2 lines

site_ansto/hardsup/modbustcp.c

@@ -0,0 +1,135 @@
+/*---------------------------------------------------------------------------
+							M O D B U S T C P . C
+
+Paul Barron, January 2008
+
+RTU Modbus functions designed for use with the WEST4100 Temperature Controller.
+If another modbus device is required at ANSTO sections of this code will need
+to be modified. 
+
+ MBAP: Modbus Application Protocol Header
+ PDU: Protocol Data Unit
+ 
+ Modbus TCP Packet Format
+|							MBAP					 		 |      PDU		 |
+|Transact Identifier|Protocol Identifier|Length Field|Unit ID|Funct Code|Data|
+|      2 Bytes 		|		2 Bytes		|   2 Bytes	 | 1 Byte|  1 Byte	| n	 |
+  
+Paul Barron, January 2008
+----------------------------------------------------------------------------*/
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <rs232controller.h>
+#include "modbustcp.h"
+
+/*-------------------------------------------------------------------------*/
+
+int ModbusTCPException(unsigned char *response);
+
+int MsgGenModbusTCP(unsigned char *ModbusMsg, int ModbusMsgLength, unsigned char *TcpPacket, 
+			int *TcpPacketLength)
+{	
+	unsigned char MBAPbyte1 = 1, MBAPbyte2 = 1;
+	unsigned char lengthByte1, lengthByte2;
+	int index;
+	   	     							
+	// Check if Device Address is Valid. This is based on RS485 having up to 
+	// 32 devices, since we currently only have one device this won't be a problem.
+	if ((ModbusMsg[0] > 32) || (ModbusMsg[0] < 1))
+	{
+		printf("Error: Modbus Address out of Range: %X\n",ModbusMsg[0]);
+		return MODBUSTCP_BadDataAddress;
+	}	
+	
+	// Check if Function code is Valid
+	if ((ModbusMsg[1] > 16) || (ModbusMsg[1] < 1))
+	{
+		printf("Error: Modbus Function Code Invalid: %X\n",ModbusMsg[1]);
+		return MODBUSTCP_BadFunction;
+	}
+	
+	// Calculate Legth Field
+	// Length should never be greater than 255 but just in case.
+	if ((ModbusMsgLength)>255){
+		lengthByte1=ModbusMsgLength/255;
+		lengthByte2=ModbusMsgLength%255;
+	}
+	else{
+		lengthByte1=0;
+		lengthByte2=ModbusMsgLength;	
+	}
+	
+	sprintf((char *)TcpPacket,"%c%c%c%c%c%c",MBAPbyte1,MBAPbyte2,0,0,lengthByte1,lengthByte2);
+	
+	for(index=0;index<=ModbusMsgLength;index++)sprintf((char *)&TcpPacket[index+6],"%c",ModbusMsg[index]);
+	
+	*TcpPacketLength=ModbusMsgLength+6;
+	
+	return 1;
+}	
+
+/*-------------------------------------------------------------------------*/
+
+int transactModbusTCP(prs232 self, unsigned char *query, int queryLength, unsigned char *response, int responseLength)
+{
+  unsigned char TCPquery[40];
+  int iRet, index, TCPqueryLength;
+	
+  // Generate the TCP message
+  iRet=MsgGenModbusTCP(query,queryLength,TCPquery,&TCPqueryLength);
+  
+  // Send the message and Read the reply
+  memset(response,0,responseLength); // puts zeros in reply up until reply length
+  if ((iRet=transactRS232(self,TCPquery,/*strlen(pCommand)*/12,response,20))<=0)
+  {
+     printf("Comms error!\n");
+     return iRet; // Comms problem
+  }	
+  					  
+  // Check that the response transact and protocol identifier are the same
+  if( (strncmp((char *)TCPquery,(char *)response,3)) == 0)
+  { 	
+	 // Check that there is not a modbus error, see page 98 from WEST4100 User manual.
+	 if ( response[7] > 0x80 )
+ 	 {
+		iRet=ModbusTCPException(response);
+		
+		return iRet;
+  	}
+  	else 
+  	{
+  		// Return the modbus response minus the TCP Header
+  		for(index=0;index<6;index++)
+			response[index]=response[index+6];
+  		
+  		return 1;
+  	}
+	
+	return 1; // Success
+  }
+  
+  return MODBUSTCP_TCPError;
+}
+
+/*-------------------------------------------------------------------------*/
+
+int ModbusTCPException(unsigned char *response)
+{	
+	if(response[8] == 0x01){
+		printf("Exception Code 01h: Illegal Function\n"); 
+		return MODBUSTCP_IllegalFunction;
+	}else if(response[8] == 0x02){
+		printf("Exception Code 02h: Illegal Data Address\n");
+		return MODBUSTCP_IllegalDataAddress;
+	}else if(response[8] == 0x03){
+		printf("Exception Code 03h: Illegal Data Value\n");
+		return MODBUSTCP_IllegalDataValue;
+	}else{
+		printf("Error code is greater than 81h, 82h or 83h\n");
+		return MODBUSTCP_UnsupportedError;
+	} 
+}
+
+/*-------------------------------------------------------------------------*/