Agilent Technologies Turbo-V 81 PCB 24 Vdc Mode D'emploi page 192

17 Technical Information
Data Exchange Protocols
Message Structure
(request and answer have the same format)
The master system (PC) starts every session sending the following
message to the slave units connected:
<STX> / <ADDR> + <WINDOW> + <COMMAND> + <DATA> + <ETX>
+ <CRC>
where:
<STX>=
<ADDR> =
<ADDR> =
<WINDOWS>= '000'...' 999' window number the meaning of the
<COMMAND>= 0x30 :window value reading
<DATA> =
<ETX>=
<CRC>=
192/208
0x02
0x80 (for RS 232 and RS 422 only)
0x80 + device number (0...31)
0xFF: broadcasting command (recognized by all the
devices, it doesn't implicate any answer)
(for RS 485 only)
window depends to the device type
0x31 :window writing
alphanumeric ASCII string containing, in the case of
writing operation, the parameter to input into the
window addressed by the field <WINDOW>This field
may have variable length according to the data type
contained in the window where you are working in.
In the case of reading request of a window, the data
field doesn't exist.
0x03
XOR among all the characters following <STX>=(with
exception of <STX>), including the end character
<ETX> hexadecimally encoded by two ASCII
characters.
Turbo-V 81 PCB 24 Vdc Controller User Manual / 87-900-121-01 (D)