Agilent Technologies 869-8928R003, User Manual

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Technical Information
RS 232/RS 485 Communication Description
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RS 232/RS 485 Communication Description
Both the RS 232 and the RS 485 interfaces are available on the
connector J6. 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
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
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>