Message Structure - Agilent Technologies TwisTorr 74 FS PCB 24 Manual De Instrucciones

Message Structure

The communication protocol is a MASTER/SLAVE type where:
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The communication is performed in the following way:
1. the host (MASTER) send a MESSAGE to the controller (SLAVE);
2. the controller answer with a MESSAGE to the host.
The MESSAGE is a string with the following format:
<STX>+<ADDR>+<WIN>+<COM>+<DATA>+<ETX>+<CRC>
where:
When a data is indicated between two quotes ('...') it means that the indicated
NOTE
data is the corresponding ASCII character.
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TwisTorr 74 FS PCB 24 Vdc Controller User Manual / 87-901-056-01
Host = MASTER
Controller = SLAVE
<STX> (Start of transmission) = one character containing 0x02
<ADDR> (Unit address) = one character containing 0x80 (for RS-
232)
<ADDR> (Unit address) = one character containing 0x80 + device
number (0 to 31) (for RS-485)
<WIN> (Window) = a string of 3 numeric characters indicating the
window number (from '000' to '999'); for the meaning of each
window see the relevant paragraph.
<COM> (Command) = one character containing 0x30 to read the
window, 0x31 to write into the window.
Technical Information
Data Exchange Protocols
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