Agilent Technologies 949-9360, User Manual

Page: 84 / 102

5
Technical Information
RS 232/RS 485 Communication Description
84/102 HS452, HS652 Rotary Vane Pumps User Manual / 87-900-978-01 (H)
Communication Format
ƒ
Physical level: both RS232 e RS485
ƒ
8 data bit
ƒ
no parity
ƒ 1 stop bit
ƒ
baud rate: 600/1200/2400/4800/9600 programmable
Communication Protocol
The communication protocol is a MASTER/SLAVE type where:
ƒ
Host = MASTER
ƒ Pump = SLAVE
The communication is performed in the following way:
1.
the host (MASTER) send a M CRC to the controller
(SLAVE);
2.
the controller answer with an CRC 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.
ƒ <STX> (Start of transmission) = 0x02
ƒ
<ADDR> (Unit address) = 0x80 (for RS 232)
ƒ <ADDR> (Unit address) = 0x80 + device number (0 to 31)
(for RS 485)