When The Qd63P6 Does Not Normally Count - Mitsubishi Electric MELSECQ Series User Manual

8
TROUBLESHOOTING
8.3
Does the input pulse waveform meet the performance
specifications?
Is the maximum speed of input pulse within the range of
the counting speed made on the intelligent function
module switch setting?
When the count value same with another channel is
input, does the count result become the same with that
of another channel?
Noise reduction
measures
Are the count value data treated in 32-bit binary in the
sequence program?
8
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When the QD63P6 Does Not Normally Count

Table 8.7 When the QD63P6 does not normally count
Check item
Are the shielded twisted pair cables
used for pulse input wiring?
Has the measures against noise been
taken to the adjacent devices and
inside the control panel?
Is the distance between the high
voltage equipment and pulse input
line kept enough?
Doesn't any noise come from the
ground part of the QD63P6?
8.3 When the QD63P6 Does Not Normally Count
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Action
Check the pulse waveform with
synchronoscope. When the input pulse does
not meet the performance specifications,
input the pulse which meets the performance
specifications.
Correct the counting speed setting in the
intelligent function module switch setting to
meet the maximum speed of the input pulse.
If they differ, it is a hardware failure. Please
consult your local Mitsubishi representative,
explaining a detailed description of the
problem.
Use the shielded twisted pair cables for
pulse input wiring.
Take noise reduction measures (e.g. attach a
CR surge suppressor to the magnet switch).
Bundle the pulse input lines and put them in
a single tube, and keep a distance of 150
mm (5.91 inch) or more with the power line
even inside the control panel.
Separate the ground cable of the QD63P6
from the ground part.
When the QD63P6 case touches to the
ground part, separate it.
Correct the sequence program so that the
count value data can be treated in 32-bit
binary.
Reference
Section 3.1
Section 4.5
-
Section 4.4
Section 3.4
CHAPTER 7