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RS 232/RS 485 COMMUNICATION
DESCRIPTION
Both the RS 232 and the RS 485 interfaces are
available on the connector J2.
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 soft-
ware.
Communication Format
• 8 data bit
• no parity
• 1 stop bit
• baud rate: 600/1200/2400/4800/9600 pro-
grammable
RS 232 Connection
RS 485 Connection
The communication port mating connector is sup-
plied with the RS232 PCB (AMP/Cannon or
equivalent 15-pin "D" type male connector).
For example, the Transmit data signal from con-
troller (pin 2) must be connected to the host com-
puter's receive data line (pin 2) and vice versa.
Consult the host computer's instruction manual for
its serial port connections.
Varian cannot guarantee compliance with FCC
regulations for radiated emissions unless all exter-
nal wiring is shielded, with the shield being termi-
nated to the metal shround on the 0-subconnector.
The cable should be secured to the connector with
screws.
Serial Communication Descriptions
This unit can communicate by two different proto-
col:
− protocol (old system) "letter"
− "Window" protocol (new system).
These two protocols can be used as well with 232
or 485 media.
Please use "Window" protocol for new develop-
ment.
WINDOW PROTOCOL
Description
Communication Format
• 8 data bit
• no parity
• 1 stop bit
• baud rate: 600/1200/2400/4800/9600 pro-
grammable
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 MESSAGE + CRC
to the controller (SLAVE);
2.
the controller answer with an ANSWER + CRC
to the host.
The MESSAGE is a string with the following format:
<STX>+<ADDR>+<WIN>+<COM>+<DATA>+<ETX>+<CRC>
80/84
TECHNICAL INFORMATION
NOTE
NOTE
87-901-003-01(A)
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