Mitsubishi Electric MELSEC Q Series Reference Manual page 308

8 TROUBLESHOOTING
Station No. 0
QCPU QJ71LP21-25
IN OUT
Cables are connected to wrong connectors at
Station No.0 (connected IN-IN with Station No.1
and OUT-OUT with Station No.4).
Station No. 0
QCPU QJ71LP21-25
IN OUT
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(2) Example of checking SW009C to SW009F
(a) When cables are connected incorrectly at a remote I/O station
(Station No.2)
1) Wiring diagram
Station No. 1
QJ72LP25-25
IN OUT
2) SW009C to SW009F status
Station No.
Station No. 1
Station No. 3
Station No. 4
Station No. 2
(b) When cables are connected incorrectly at the remote master
station (Station No.0)
1) Wiring diagram
Station No. 1
QJ72LP25-25
IN OUT
2) SW009C to SW009F status
Station No.
Station No. 1
Station No. 2
Station No. 3
Station No. 4
Cables are connected to wrong connectors
at Station No. 2 (connected OUT-OUT with
Station No. 1 and IN-IN with Station No. 3).
Station No. 2
QJ72LP25-25
IN OUT
SW009C to SW009F status
Only Station No. 2 (bit 1) is ON or OFF.
b15
SW009C
SW009D
SW009E
SW009F
All stations (bit 0, bit 2, bit 3) than Station No. 2 (bit 1) are ON or OFF.
b15
SW009C
SW009D
SW009E
SW009F
Station No. 2
QJ72LP25-25
IN OUT
SW009C to SW009F status
All areas for Station No.1 to 4 (bit0 to bit3) turn ON.
b15
SW009C
SW009D
SW009E
SW009F
MELSEC-Q
Station No. 3 Station No. 4
QJ72LP25-25 QJ72LP25-25
IN OUT
to b4 b3 b2
0 0 0
0
0
0
to b4 b3 b2
0 1 1
0
0
0
Station No. 3 Station No. 4
QJ72LP25-25 QJ72LP25-25
IN OUT
to b4 b3 b2
0 1 1
0
0
0
IN OUT
b1 b0
1 0
b1 b0
0 1
IN OUT
b1 b0
1 1
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