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

8
TROUBLESHOOTING
8.2.4

When an analog output value is not output

Check item
Is 24VDC being supplied from the external power supply? (If not,
"External power supply (X7)" is OFF.)
Is there any fault with the analog signal lines such as broken or dis-
connected line?
Is the CPU module in the STOP status?
Are the offset/gain settings correct?
Is the output setting range correct?
Is the resolution mode setting correct?
Is the D/A conversion enable/disable setting for the channel to be
output set to Disable?
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 the operating condition setting request (Y9) been executed?
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.
Please consult your local Mitsubishi representative, explaining a detailed descrip-
tion of the problem.
8.2.4 When an analog output value is not output
Action to be taken
Verify that 24VDC voltage is being supplied to the external power
supply terminals (between terminals No. A19 and A20 or B19 and
B20).
Check for any abnormality on the signal lines by a visual check and 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 being used, switch to a different default
input range and check if D/A conversion is correctly performed. If it is
correctly performed, redo the offset/gain settings.
Verify setting range (Un\G20, Un\G21) 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 the ON/OFF status of the high resolution mode status flag (X8)
in GX Developer system monitor.
If the resolution mode setting is incorrect, redo the GX Developer
intelligent function module switch setting. (Refer to Section 4.5).
Check the D/A conversion enable/disable setting (Un\G0) in GX
Developer monitor and set it to Enable using the sequence program
or utility package (Refer to Section 3.4).
Verify ON/OFF for the C output enable/disable flags (Y1 to Y6) in GX
Developer monitor.
If the output enable/disable flags are OFF, review the initial setting for
the sequence program or utility package (Refer to Section 3.3).
Verify CH digital value (Un\G1 to Un\G6) in GX Developer monitor
(Refer to Section 3.4).
Set the operating condition setting request (Y9) from ON to OFF from
GX Developer and check to Refer to if the analog output is normal.
If normal analog output is obtained, review the initial setting for the
sequence program or utility package (Refer to Section 3.3).
8.2 Troubleshooting
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