P2 - Serial; Input Power Connection On The Model 969-8972; Rs 232/Rs 485 Communication Description; Communication Format - Varian TV 301 Manual De Instrucciones

How to connect the outputs of the controller
The following figure shows a typical logic output
connection (relay coil) but any other device may
be connected e.g. a LED, a computer, etc., and
the related simplified circuit of the controller. The
figure example refers to the programmable set
point signal on pins 11 and 9.
Typical output connection

P2 - Serial

This is a 9 pin D-type serial input/output connector
to control via an RS 232 or RS 485 connection the
TV 301.
PIN N. SIGNAL NAME
1 +5 V (OUT)
2 TX (RS232)
3 RX (RS232)
4 A+ (RS422 Optional)
5 GND
6 A + (RS485)
7 B - (RS422 Optional)
8 B - (RS485)
9 RESERVED
Note that the vent valve can also be controlled by
means of the serial connection.
A serial communication kit with a serial cable and
the Navigation software is available (optional).
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33
TECHNICAL INFORMATION
INPUT POWER CONNECTION ON THE MODEL
969-8972
The following figure shows the input power con-
nection relevant to the model n. 969-8972.
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 Navi-
gator software.

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>
where:
NOTE
When a data is indicated between two quotes ('...')
it means that the indicated data is the correspond-
ing ASCII character.
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