When The Digital Output Values Cannot Be Read - Mitsubishi Electric Melsec Q Series User Manual

8 TROUBLESHOOTING

8.2.3 When the digital output values cannot be read

Is there any fault with the analog signal lines such as
disconnection?
Is the CPU module in the STOP status?
Are the offset/gain settings correct?
Is the input range setting correct?
Is the resolution mode setting correct?
Is A/D conversion enable/disable setting for the channels to
use set to A/D conversion disabled?
Has Operating condition setting request (Y9) been
executed?
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Check item
POINT
The module may be faulty if Digital output value cannot be read after proper
corrective actions have been taken according to the above check items. Consult
the nearest representative or branch.
Corrective action
Check for faulty condition of the lines visually and perform a
continuity check of the signal lines.
Set the CPU module to the RUN status.
Verify that the offset/gain settings are correct (refer to
Sections 4.6, 5.6.2 and 5.6.3).
If the user range is being used, switch to a different default
input range and check if A/D conversion is correctly
performed. If it is correctly performed, redo the offset/gain
settings.
Check Setting range (buffer memory address 20, 21:
Un\G20, Un\G21) in GX Developer system monitor.
If the input range setting is incorrect, reset the intelligent
function module switch of GX Developer (refer to Section
4.5).
Check the on/off status of High resolution mode status flag
(X8) in GX Developer system monitor.
If the resolution mode setting is incorrect, reset the intelligent
function module switch of GX Developer. (refer to Section
4.5.)
Check the on/off status with A/D conversion enable/disable
setting (buffer memory address 0: Un\G0) in GX Developer
system monitor and review the initial setting of the sequence
program or utility package (refer to Section 3.4).
From GX Developer, set Operating condition setting request
(Y9) from on to off, and check if a digital output value is
stored in CH Digital output value (buffer memory address
11 to 18: Un\G11 to Un\G18). If so, review the initial setting
of the sequence program or utility package (refer to Section
3.3).
MELSEC-Q
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