When An Analog Output Value Is Not Output - Mitsubishi Electric MELSEC Q Series User Manual

8 TROUBLESHOOTING

8.2.4 When an analog output value is not output

Is 24VDC external power supply being supplied?
Is there any fault with the analog signal lines such as broken
or disconnected line?
Is the CPU module in the STOP status?
Are the offset/gain settings correct?
Is the output setting range correct?
Is D/A conversion enable/disable setting for the channel to
be output set to D/A conversion disabled?
Is the D/A output enable/disable setting for the channel to be
output set to Disable?
Is the digital value being written to the channel to be output?
Has Operating condition setting request (Y9) been
executed?
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Check item
POINT
If the analog output value is not output after the proper corrective action is taken in
accordance with the above check item, the possible cause is a module failure.
Consult the nearest sales representative or branch.
Action to be taken
Verify that 24VDC voltage is being supplied to the external
power supply terminals (terminal numbers 16, 17).
Check for any abnormality on the signal lines by doing a
visual check and performing a continuity check.
Set the CPU module to the RUN status.
Verify that the offset/gain settings are correct (Refer to
sections 4.6 and 5.6.2).
If the user range setting is set to the Q62DA-FG, switch the
output range to one of defaults. Then check if D/A
conversion is performed correctly. If the input is properly
converted, reconfigure the offset/gain settings.
Verify buffer memory address 20 (Un\G20) in GX Developer
monitor. If the output range setting is incorrect, redo GX
Developer intelligent function module switch settings
(Refer to Section 4.5).
Check D/A conversion enable/disable setting using buffer
memory 0 (Un\G0) in GX Developer monitor and set it to
Enable using the sequence program or utility package
(Refer to Section 3.4).
Check the on/off status of Output enable/disable flag (Y1,
Y2) in GX Developer monitor.
If Output enable/disable flag (Y1, Y2) is off, check the
sequence program (Refer to Section 3.3), or check that the
CPU module is not in STOP state.
Verify buffer memory address 1, 2 (Un\G1, Un\G2) in GX
Developer monitor (Refer to Section 3.4).
Turn on and off Operating condition setting request (Y9)
using GX Developer, and check whether an analog value
that is output is normal.
If the analog value is normal, check whether descriptions
related to Operating condition setting request (Y9) are
correct on the sequence program (Refer to Section 3.3).
MELSEC-Q
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