Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 416

8 TROUBLESHOOTING
QCPU QJ71LP21-25
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(2) Example of checking SW009C to SW009F
An example of incorrect cable connection at Station No. 2 is shown below.
(a) Wiring diagram
Station No. 1 Station No. 2
QCPU QJ71LP21-25
IN OUT IN
(b) SW009C to SW009F status
Station No.
Station No. 1
Station No. 3
Station No. 4
Station No. 2
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. 3
QCPU QJ71LP21-25
OUT IN
Only Station No. 2 (bit 1) is ON or OFF.
b15
SW009C
SW009D
SW009E
SW009F
All stations (bit 0, bit 2, bit 3) other than Station No. 2 (bit 1) are ON or OFF.
SW009C
SW009D
SW009E
SW009F
Station No. 4
QCPU QJ71LP21-25
OUT IN OUT
SW009C to SW009F status
to b4
0
0
0
0
b15 to b4
0
0
0
0
MELSEC-Q
b3 b2 b1 b0
0 0 1 0
b3 b2 b1 b0
1 1 0 1
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