Troubleshooting By Symptom; Main A/D Converter Module - Mitsubishi Electric NZ2EX2B-60AD4 User Manual

11.6

Troubleshooting by Symptom

This section describes troubleshooting problem by problem.
Troubleshooting by symptom is suitable for the case where modules fail to operate normally even though no error has
occurred in the A/D converter module. If an error occurs in the A/D converter module, identify the cause of the error
using the engineering tool.
11.6.1

Main A/D converter module

(1) When digital operation value cannot be read
Check item
Is there any problem with the wiring, such as looseness or
disconnection of analog signal lines?
Is the CPU module in the STOP status?
Is the offset/gain setting correct?
Is the input range setting correct?
Is A/D conversion disabled for the channels where the analog
value is to be input?
Is Initial data setting request flag (RY9) executed?
Are the (V+) and (I+) terminals connected when the current is
input?
Are the setting values of the averaging process setting
correct?
Is there any potential difference between the AG terminal and
the external device GND?
Is the network synchronous communication setting
(Synchronous or Asynchronous) changed in the network
configuration setting?
Is an inter-module synchronous interrupt program prepared
when the CC-Link IE Field Network synchronous
communication function is used together with the inter-
module synchronization function on the MELSEC iQ-R
series?
If the digital operation value cannot be read even after the above actions are taken, the failure of the main A/D converter
module is a possible cause.
Please consult your local Mitsubishi representative.
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Identify the faulty area of signal lines by a visual check and a continuity check.
Change the status of the CPU module to RUN.
Check if the offset/gain setting is correct.
If the user range is used, change the input range to any of the default settings, and then check
if the A/D conversion is performed properly. If the A/D conversion is properly executed,
configure the offset/gain setting again.
Verify Range setting (address: 0103H) by using the engineering tool or the dedicated
instruction.
If the input range setting is incorrect, set the range again by engineering tool or program.
Check A/D conversion enable/disable setting (address: 0102H) by using the engineering tool
or the dedicated instruction. Then, set A/D conversion to be enabled by program or
engineering tool.
Turn on and off Initial data setting request flag (RY9) using the engineering tool to check if the
digital operation value is stored in CH Digital operation value (RWr2 to RWr5).
When the problem has been solved, check the program again.
For the current input, always connect the terminals (V+) and (I+) referring to the following.
• Wiring of External Device and Terminal Block ( Page 63, Section 6.6)
When the time average processing is selected, set the value to be not less than "Four (times)
× Sampling period".
If the condition above is not met, 0 is stored into the digital operation value.
Connect the AG terminal and the external device GND.
If the network synchronous communication setting is changed, turn off and on the power or
perform remote reset.
For the combined use of the CC-Link IE Field Network synchronous communication function
and the inter-module synchronization function on the MELSEC iQ-R series, prepare an inter-
module synchronous interrupt program.
For the inter-module synchronous interrupt program, refer to the following:
 MELSEC iQ-R Inter-Module Synchronization Function Reference Manual
Action