Loop Test (Optical Loop System Only) - Mitsubishi Electric QJ71LP21 Reference Manual

4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION

4.10.1 Loop test (optical loop system only)

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This test checks the line status of the forward and reverse loops upon completion of
the wiring of the optical loop system. Also, when a loopback is being executed, it
checks the station that executes the loopback.
For example, in the system shown below, where the IN/OUT connectors of station
number 5 are connected in reverse, conduct a loop test using the GX Developer
connected to remote master station.
The monitoring screen below is displayed after the loop test has been executed, and
station No. 5 is detected as the receive direction error station.
GX Developer
Remote
master station
OUT
Reserved station
Station Station
No. 0 No. 3
IN OUT IN OUT
OUT IN
IN
Station
Station
No. 7
No. 1
Loopback
Station Station
No. 6 No. 4
IN OUT IN OUT
OUT IN IN OUT
Station Station
No. 2 No. 5
Loopback Faulty station
MELSEC-Q
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