Loopback Test; Executing Loopback Tests; Overview; Connection Method - Omron CJ1W-SCU32 Operation Manual

8 Loopback Test

8-1

Executing Loopback Tests

8-1-1

Overview

The loopback test is a testing function for a communications circuit. The Serial Communications Unit
compares transmitted data and loopback data. To perform loopback tests, connect a loop backwire con-
nector to the port of Serial Communications Unit.
Serial Communications Unit
Loopback test
8-1-2

Connection Method

Make the connections according to the type of port, as shown in the following diagrams.
RS-232C Port
Pin
2
3
4
5
1
8
7
RS-422A/485 Port
Pin
1
2
3
4
8-1-3

Procedure

The loopback test is performed using the procedure shown below.
1
Connect the connector of the port to be used to execute the loopback test. See 8-1-2 Connec-
tion Method for details.
2
Set the serial communications mode to Loopback Test (F hex) using the applicable CJ-series
Unit Device Variables for System Setting. Refer to 8-2-1 Device Variables for CJ-Series Unit for
System Settings.
3
Set the following communication settings for the loopback test in the Device Variables for CJ-
Series Unit for System Settings: Baud Rate, Stop Bits, Parity, and Data Length. For details, refer
to 8-2-1 Device Variables for CJ-Series Unit for System Settings.
8-2
Loopback test switch
The loopback test results
are stored.
Signal
SD
RD
RTS
CTS
FG
DTR
DSR
Signal
RDA
RDB
SDA
SDB
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)