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Teledyne API Model 465L O3 Monitor Operation Manual
05509G DCN6806
Teledyne API Model 465L O
3
Monitor Manual
55
8.3.
RS-232 Configuration
The RS-232 configuration is usually used when making a one-to-one connection
between the instrument and a single computer or PLC. The communications
protocol used for the RS-232 configuration is MODBUS RTU. For details on the
MODBUS RTU specification, please see
http://www.modbus.org/
.
With the instrument configured for RS-232, connection can be made to the DB-9
connector, labeled “RS232/485”, or to the three “COM” pins on the “General I/O”
connector. Only one of these connections should be used, the other must be left un-
connected. Table 8-1 below details the pinouts of these two connectors:
Table 8-1: RS-232 Connector Details
Function
DB-9
Connector Pin
(SW2 – DTE)
DB-9
Connector Pin
(SW2 – DCE)
General I/O
Connector
Transmit (Tx)
3
2
‘T’
Receive (Rx)
2
3
‘R’
Ground
5
5
‘G’
Note that a DTE-DCE switch is provided so that the instrument can be connected to
another device using either a straight-through or crossover (Null-Modem) cable.
See Section 8.2 for details on changing this configuration.
The serial port setup for RS-232 configuration is shown in Table 8-2 below:
Table 8-2: RS-232 Port Setup
Property
Value
Baud Rate
57600
Data Bits
8
Parity
None
Stop Bits
1
Flow Control
None
Summary of Contents for 465L
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