Experimental Physics and
Industrial Control System

HI Tech-talk,I am trying to build an IOC to communicate with serial devices through the serial to Ethernet Device Server.

The serial device supports  the streams of hex format.

The binary command format when using RS232 or RS485 is as follows:
Bytes    Meaning
1        Module address
1        Command number
1        Type number
1        Motor or Bank number
4        Value (MSB first!)
1        Checksum
total:  9 bytes

the checksum is calculated by adding up all bytes (including the module address byte) using
8-bit addition. Here is the examples to show how to do this:
    in C:
    unsigned char i, Checksum;
    unsigned char Command[9];

    //Set the “Command” array to the desired command
    Checksum = Command[0];
    for(i=1; i<8; i++)
        Checksum+=Command[i];
    Command[8]=Checksum; //insert checksum as last byte of the command
     //Now, send it to the module

I want to control the motor to rotate right  through the serial device.

Instruction:
Rotate right,   motor #1, velocity = 350
Binary:
Byte Index         0              1                2          3                   4                5                 6               7                 8
Function          Target-     Instruction   Type      Motor/         Operand     Operand      Operand     Operand      Checksum
                   address     Number                      Bank           Byte3         Byte2           Byte1          Byte0
Value (hex)        0x01       0x01          0x00      0x01             0x00          0x00             0x01            0x5e          0x62

By writing streamDevice protocol file(out'\x01\x01\x00\x01\x00\x00\x01\x5e\x62';),motor can rotate. Using "EDM" or "caput" to

input the variable,where do I do my processing (like calculating the Checksum and convert the velocity to four bytes long)? where

write my own parsing code in C?having other approaches. Could you give any example?

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