Troubleshooting By Symptom; Inputs From External Devices Are Not Performed; Incorrect Inputs From External Devices Are Performed; Outputs To External Devices Are Not Performed - Mitsubishi Electric MELSEC-L Series LD40PD01 User Manual

14.5

Troubleshooting by Symptom

Inputs from external devices are not performed

Check item
Is the LED0 on?
Is the control of the hardware logic working?
Are the block layout and links between blocks in the hardware logic correct?

Incorrect inputs from external devices are performed

Check item
Measures to Is the filter time setting of external input blocks correct?
reduce
Have twisted pair shielded cables been used for the pulse
noise
input cables?
Have measures to reduce noise been taken in the control
panel or for adjacent devices?
Is there a sufficient distance between the high voltage device
and the pulse input cables?
Is the module affected by noise through the grounding area?
Are the power cables and I/O cables bundled together?
Is the external wiring connected to unused terminals?

Outputs to external devices are not performed

Check item
Is the LED1 on?
Is the external wiring correct?
Is the control of the hardware logic working?
Are the block layout and links between blocks in the hardware logic correct?

The hardware logic does not function

Check item
Is the control of the hardware logic working?
Are the block layout and links between blocks in the hardware logic correct?
Is the CPU module indicating an error?
Action
Check the external wiring and make necessary corrections.
When Hardware logic control flag (X4) is off, turn on Hardware logic control
start request (Y4) to start the hardware logic control.
Check the block layout and links between blocks in the hardware logic and
make necessary corrections.
Action
Set the filter time of the external input blocks longer.
Use twisted pair shielded cables for the pulse input cables.
Take measures to reduce noise such as attaching a CR surge suppressor to
the magnet switch or other device.
Wire the pulse input cables alone when placing them in a duct, and keep a
distance of 150mm or more from the power cables in the control panel.
Separate the grounding cable of the flexible high-speed I/O control module
from the grounding area.
Do not bundle the power cables and I/O cables together.
Do not connect the external wiring to unused terminals.
Action
Check the block layout and links between blocks in the hardware logic and
make necessary corrections.
Check the external wiring and make necessary corrections.
When Hardware logic control flag (X4) is off, turn on Hardware logic control
start request (Y4) to start the hardware logic control.
Check the block layout and links between blocks in the hardware logic and
make necessary corrections.
Action
When Hardware logic control flag (X4) is off, turn on Hardware logic control
start request (Y4) to start the hardware logic control.
Check the block layout and links between blocks in the hardware logic and
make necessary corrections.
If the CPU module is in an error status, refer to the troubleshooting in the
user's manual for the CPU module used and take corrective actions to restore
normal operation of the CPU module.
14.5 Troubleshooting by Symptom
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