Mitsubishi Electric MELSEC iQ-F FX5 User Manual page 413

■When the ERROR LED turns on or flashes
• When it is on
Check item
Check whether any error has occurred.
• When flashing
Check item
Check whether 24 V DC external supply power shutdown has occurred.
■When the ALM LED turns on or flashes
• When it is on
Check item
Check whether any alert has been issued.
• When flashing
Check item
Check whether any input signal error has occurred.
■When a digital output value cannot be read
Check item
Check whether an analog signal line is disconnected from the multiple input
module.
Check whether the CPU module is in the STOP state.
Check whether the offset/gain setting in the user range setting is correct.
Check whether the input type/input range setting are correct.
Check whether 'Operating condition setting request' (Un\G70, b9) has been
executed.
Check whether the setting value of the time average is correct when the time
average is selected in Averaging process specification.
*1 The conversion does not start when 'Operating condition setting request' (Un\G70, b9) is on. After turning offon, check that 'Operating
condition setting completed flag' (Un\G69, b9) is off, and then make sure to turn onoff.
■When the digital output value does not fall within the range of accuracy
Check item
Check whether any measures have been taken to reduce noise.
Is an external input being made to a conversion disabled channel?
Corrective action
Check 'Latest error code' (Un\G0) and take actions described in the list of
error codes.
Page 414 List of error codes
Corrective action
Check that FX5-8AD and 24 V DC external power supply are properly
connected.
Additionally, before turning on the system power supply, check that the voltage
supply from the 24 V DC external power supply is started to FX5-8AD.
Corrective action
Check Alert output flag (Process alarm upper limit), Alert output flag (Process
alarm lower limit), Alert output flag (Rate alarm upper limit), and Alert output
flag (Rate alarm lower limit).
Take actions described in the list of alarm codes.
Page 417 List of alarm codes
Corrective action
Check Input signal error detection signal or Input signal error detection flag.
Take actions described in the list of alarm codes.
Page 417 List of alarm codes
Corrective action
Visually check signal lines and correctly connect analog signal lines.
Change the state of the CPU module to RUN.
Check that the offset/gain setting is correct.
If the user range setting is selected, change the other input range to the
factory shipment setting, and check that the conversion is performed.
Reconfigure the offset/gain setting when the conversion is correct.
Check CH Input type/Range monitor with GX Works3. When the input type/
input range setting are incorrect, reconfigure the input type and input range
setting again.
*1
Turn offonoff 'Operating condition setting request' (Un\G70, b9) and
check that a digital output value is stored in 'CH1 Digital output value'
(Un\G400) using GX Works3. If the stored value is correct, check the program.
When the time average is selected for processing, set the time average value
in CH1 Time average/Count average/Moving average setting so that the value
satisfies the following condition:
• Time average setting value  4 (times)  1 (ms)  Number of input type
current/voltage specified channel
If the condition above is not satisfied, the digital output value results in 0.
Corrective action
To reduce noise, take measures such as the use of shielded cables for
connection.
Do not input to a conversion disabled channel from an external device.
3 FX5-8AD
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3.10 Troubleshooting
3