When A Digital Output Value Cannot Be Read - Mitsubishi Electric R60AD8-G User Manual

When a digital output value cannot be read

Check item
Check whether there is any problem with the wiring, such as looseness or
disconnection of analog signal lines.
Check whether the CPU module is in the STOP state.
Check whether the offset/gain setting is correct.
Check whether the input range setting is correct.
Check whether A/D conversion disable is set in A/D conversion enable/disable
setting of the channel where a value is to be input.
Check whether 'Operating condition setting request' (Y9) has been executed.
Check whether the terminals (V+) and (I+) are connected at the current input.
Check whether the setting value of the time average is correct when the time
average is selected in Averaging process specification.
Check whether the program for reading digital output values has an error.
Check whether the refresh setting is correct.
Check whether any input signal error has occurred.
*1 If 'Operating condition setting request' (Y9) is in an on state, A/D conversion does not start. In such a case, turn off and on it to check the
off state of 'Operating condition setting completed flag' (X9), and be sure to turn on and off it.
If digital output values cannot be read even after the above actions are taken, the possible cause is a failure of
the module. Please consult your local Mitsubishi representative.
3 TROUBLESHOOTING
106
3.3 Troubleshooting by Symptom
Corrective Action
Identify the faulty area of signal lines by a visual check and continuity check.
Change the state of the CPU module to RUN.
If the input range setting is the user range setting, turn on and off 'Operating
condition setting request' (Y9), and check CH User range setting offset
value and CH User range setting gain value comparing with the range
reference table.
If the stored values are not desired offset/gain values, perform the offset/gain
setting again.
For the range reference table, refer to the following.
Page 94 Range reference table
Check CH Range setting monitor using the engineering tool.
If the input range is incorrect, correctly set the input range setting of the
engineering tool and/or CH Range setting.
Check CH A/D conversion enable/disable setting and set to A/D conversion
enable using a program or the engineering tool.
*1
Turn on and off 'Operating condition setting request' (Y9) and check that a
digital output value is stored in CH Digital output value using the engineering
tool.
If the stored value is correct, further check if 'Operating condition setting
request' (Y9) operates properly in the program.
For the current input, be sure to connect the terminals (V+) and (I+) by
referring to the external wiring example.
 MELSEC iQ-R Channel Isolated Analog-Digital Converter Module User's
Manual (Startup)
When the time average is selected for processing, set the time average value
in CH Time average/Count average/Moving average/Primary delay filter
constant setting so that the value satisfies the following condition:
Time averaging setting value  4 (times)  10ms  Number of conversion
enabled channels
If the condition above is not satisfied, the digital output value results in 0.
Check CH Digital output value using the engineering tool. If the digital output
value is stored without being converted from the analog input value, review
and correct the read program.
If the refresh is set so that the value in CH Digital output value is transferred
to the device of the CPU module, review and correct the auto refresh setting.
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' (Un\G40) 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 38 Input Signal Error Detection Function
If the values are valid, change the analog input value so that an input signal
error does not occur.