Mitsubishi Electric MELSEC iQ-F FX5 User Manual page 104

Check item
Check whether any input signal error has occurred.
*1 The A/D 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.
Check whether no external input has occurred to the conversion disabled
channel.
Digital output value varies
Check item
Check whether an A/D conversion method other than sampling processing
is set.
The A/D conversion completed flag does not turn on
Check item
Check whether all channels are set to be A/D conversion disabled.
1 FX5-4AD
102
1.10 Troubleshooting
Corrective action
The digital output value and digital operation value are not updated during the
occurrence of an input signal error.
If Input signal error detection flag indicates an input signal error, check the
values in CH Input signal error detection setting and CH Input signal error
detection setting value to examine the validity of the input signal error detection
upper limit value and the input signal error detection lower limit value.
Page 53 Input signal error detection function
If the values are valid, change the analog input value so that an input signal error
does not occur.
Corrective action
To reduce noise, take measures such as the use of shielded cables for
connection.
Do not input anything to the A/D conversion disabled channel from an external
device.
Corrective action
Check the setting of average processing specification from the "Module
parameter setting" screen of GX Works3.
Review the setting of average processing specification and check the state of
variation of CH Digital output value again.
Corrective action
Check the A/D conversion enable/disable setting with GX Works3.
If there are only A/D conversion enabled channels, set the A/D conversion
enable/disable setting to "A/D conversion enabled" for one or more channel the
sequence program.