Mitsubishi Q01CPU User Manual page 585

12
TROUBLESHOOTING
Situation
The load [2] which was turned OFF may be turned ON due to
back electromotive force at the time of power-off [1] if an
inductive load is used.
The load which
was turned
OFF is turned
ON for a
moment at
power-off.
(Transistor
output)
Table12.20 Output circuit troubleshooting (Continued)
Cause
Output module,
combined module
Back
Sink output
electromotive
force
ON
TB1 ON
[2]
TB2 OFF
OFF
[1]Shut off
COM+
CTL-
Output module,
combined module
Back
Sink output
electromotive
force
ON
TB1 ON
[2]
TB2 OFF
OFF
[1]Shut off
COM-
CTL+
To prevent the generation of the back
electromotive force, connect diode in
parallel with load where the back
electromotive force has been generated.
Source output
[3]
[3]
Load
Load
Sink output
[3]
[3]
Load
Load
12.5 I/O Module Troubleshooting
12.5.2 Output Circuit Troubleshooting
Countermeasure
Back
electromotive
force
Load
Back
electromotive
force
Load
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