Communication Format; Communication Protocol - Agilent Technologies TwisTorr Medium-TMP Bedienungshandbuch

17 Technical Information
RS 232/RS 485 Communication Description

Communication Format

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Communication Protocol

The communication protocol is a MASTER/SLAVE type where:
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The communication is performed in the following way:
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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 data is
NOTE
the corresponding ASCII character.
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232/284
8 data bit
no parity
1 stop bit
baud rate: 600 / 1200 / 2400 / 4800 / 9600 / 19200 / 38400
programmable (default setting: 9600)
Host = MASTER
Controller = SLAVE
the host (MASTER) send a message + CRC to the controller
(SLAVE);
the controller answer with an answer + CRC to the host.
<STX> (Start of transmission) = 0x02
<ADDR> (Unit address) = 0x80 (for RS 232)
<ADDR> (Unit address) = 0x80 + device number (0 to 31) (for RS
485)
<WIN> (Window) = a string of 3 numeric character indicating the
window number (from '000' to '999'); for the meaning of each
window see the relevant paragraph.
TwisTorr Medium-TMP Rack Controller User Manual / 87-901-049-01