Mitsubishi MELSEC QJ71C24, User Manual

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MELSEC-Q
4 SETTINGS AND PROCEDURES PRIOR TO OPERATION
4.7.2 Individual station loopback test
The individual station loopback test checks the operation of the communication
function of the Q series C24.
Follow the procedure below to perform an individual station loopback test.
(Procedure 1) Connecting cable
(1) Connect cables to two interfaces as follows.
• Connect cables to the RS-232 interface within the connector and install it to the
interface.
• Connect cables to the RS-422/485 interface on a terminal block.
(Procedure 2) Communication protocol setting and transmission setting (see Section 4.5.2)
(1) Set the communication protocol setting to F
H
(individual station loopback test) for
both interfaces.
(2) Set transmission setting of the two interfaces according to the transmission
specification for data communication with an external device.
(Procedure 3) Performing the individual station loopback test
(1) Set the programmable controller CPU to STOP status.
(2) Restart the programmable controller CPU station or reset the CPU. The test starts
automatically in about one second.
(3) For the Q series C24, perform the following tests in sequence and repeat them
(one test cycle takes approximately one second).
End testing when all test results become abnormal.
1) Check communication with the programmable controller CPU
Read and check the model type of the programmable controller CPU.
2) Check transmission and reception functions of the interface
Perform communication while changing data.
(4) The LED corresponding to a test item flashes when the test starts.
• The CH1 NEU LEDs flash when checking communication with the programmable
controller CPU.
• The SD and RD LEDs of the interface being tested flash when checking the
communication functions of interface.