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MELSEC-Q
4 SETTING AND PROCEDURE BEFORE OPERATION
4.7 Unit Tests of the Network Module (Offline Test)
The network module and the connected cable shall be tested before executing the
data link operation. Select the test item with the mode setting switch on the front of the
network module. The following three items are provided as the offline test.
(1) Self-loopback test (mode setting switch: 1 or 5)
This test checks the internal circuits including the send/receive circuits of the
network module together with the connected cable.
(2) Internal self-loopback test (mode setting switch: 2 or 6)
This test checks the internal circuits including the send/receive circuits of the
network module.
(3) Hardware test (mode setting switch: 3 or 7)
This test checks the internal components of the network module.
Test start
Self-loopback test
Mode setting switch: 1 or 5
Test result?
Test completed
Internal self-loopback test
Mode setting switch: 2 or 6
Test result?
Hardware test
Mode setting switch: 3 or 7
Test result?
Defective send/receive
circuit
Corrective action:
Replace module
Defective cable
Corrective action:
Replace cable
Defective internal circuit
Corrective action:
Replace module
NG
NG
NG
OK
OK
OK
Flow of offline tests
POINT
If the test completes with an error, the possible cause is a hardware failure of the
network module. Please consult your local Mitsubishi representative.
REMARKS
If even one station is set to the test mode (offline, mode setting switch 1 to 3 or 5 to
7) during the data link (online), the normal data link cannot be maintained.