Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Wed, 17 Nov 2010 00:04:22 +0100

out “\x01\x01\x00\x01%.4r%<sum>”;
or
out $1 0x01 $2 $3 “%.4r%<sum>”;
%4r would sign extend 1 byte data to 4 bytes output.
%.4r prints 4 byte data.
The documentation is wrong here. I will fix that.
Dirk
[email protected] wrote:

I think the stream device protocol converters %r and %<sum> will do what
you want :

out “\x01\x01\x00\x01%4r%<sum>”;

But you would probably want to pass the address information as variables :

out $1 0x01 $2 $3 “%4r%<sum>”;

*From:* [email protected]
[mailto:[email protected]] *On Behalf Of *Damek Yahto

*Sent:* 16 November 2010 03:06

*To:* [email protected]

*Subject:* the hex instruction convert

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 will 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?
Thanks,
Yahto Dam
2010.11.16

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System