Agilent Technologies TwisTorr 84 FS PCB, Руководство пользователя

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Technical Information
Data Exchange Protocols
17
Message Structure
The communication protocol is a MASTER/SLAVE type where:

Host = MASTER

Controller = SLAVE
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:
NOTE
When a data is indicated between two quotes (‘...’) it means that the indicated
data is the corresponding ASCII character.

<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.
TwisTorr 84 FS PCB 24 Vdc Controller User Manual / 87-901-039-01 (B) 191/210