Agilent Technologies TV 551 Navigator, User Manual

Page: 287 / 328

Technical Information
How to Connect the Open-Collector Inputs of the Controller
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TV 551/701 Navigator User Manual / 87-900-934-01 (P) 287/328
RS 232/RS 485 Communication Description
Both the RS 232 and the RS 485 interfaces are available on the connector P2.
The communication protocol is the same (see the structure below), but only
the RS 485 manages the address field. Therefore to enable the RS 485 is
necessary to select the type of communication as well as the device address by
means of the Navigator software.
Communication Format

8 data bit

no parity

1 stop bit

baud rate: 600/1200/2400/4800/9600 programmable
Communication Protocol
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
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.

<STX>
(Start of transmission) = 0x02