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CHAPTER 11 TROUBLESHOOTING
11
11.6 Troubleshooting
(4) When digital output value cannot be read
If digital output value cannot be read even after taking the above actions, the A/D converter module may be failed.
Please consult a local Mitsubishi representative.
(5) When an A/D conversion completed flag does not turn on in the normal mode
Check item Action
Is there any problem with wiring, such as off or disconnection of
analog signal lines?
Check the faulty area by checking signal line visually or
conductively.
Is the CPU module in the STOP status? Change the status of the CPU module to RUN.
Is the offset/gain setting correct?
Check if the offset/gain setting is correct.
When the user range setting is selected, change the input range to
the factory default setting. Then check if the A/D conversion
executes.
If the A/D conversion is properly executed, configure the offset/gain
setting again.
Is input range setting correct?
Check Setting range (Un\G20). When the setting range is wrong,
perform the intelligent function module switch setting again.
Of the channels to input the analog value, is there any channel,
whose A/D conversion enable/disable setting (Un\G0) set to the A/D
conversion disable?
Check A/D conversion enable/disable setting (Un\G0). Then, set the
A/D conversion enable for Un\G0 with the program or the parameter
of the intelligent function module.
Is Operating condition setting request (Y9) performed?
Check if the digital output value is stored in the CH Digital output
value (Un\G11 to Un\G14) after turning Operating condition setting
request (Y9) from OFF to ON, then to OFF.
When the problem has been solved, check the program again.
Are the (V+) and (I+) terminals connected if the input source is
current?
Make sure to connect the (V+) and (I+) terminals while inputting
current as shown in the external wiring.
Are the setting values correct when the average processing is
specified?
When selecting the time average processing, set the values satisfy
the following condition.
• Setting value ≥ "4 (times) × conversion speed × Number of used
channels"
If the condition above is not met, digital output values remain 0.
Is there any potential difference between the AG terminal and the
external device GND?
Connect the AG terminal and the external device GND
Check item Action
Isn't there any input signal error? Check Input signal error detection flag (Un\G49)
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