When The Digital Output Value Does Not Fall Within The Range Of Accuracy - Mitsubishi Electric Melsec iQ-R Series User Manual

Check item 3
The external power supply of 24VDC is not supplied to the A/D converter module. Check the following items.
Check item
Check whether the external power supply of 24VDC is supplied to
the A/D converter module.
(1) Check whether the cables are wired correctly.
(2) Check whether the external power supply of 24VDC is supplied
within the specified range.
Cases other than the above
Check item 4
The cables are not wired correctly. Check the following items.
Check item
Check whether solderless terminals used meet the specifications.
Check whether an incorrect terminal is not connected.
Check whether there is any problem with the wiring, such as
looseness or disconnection of analog signal wires.
Check whether the voltage required to operate the connected
HART-enabled device is supplied to the connected HART-enabled
device.
Check item 5
The analog input and input range setting do not match. Check the following items.
Check item
Check whether "Input range setting" of the module parameter is
correct.
When an input range is set in 'CH1 Range setting' (Un\G598) with
a program, check whether the program has any error.
Check whether 'Operating condition setting request' (Y9) has been
executed after parameter changes.
*1 If 'Operating condition setting request' (Y9) is on, the A/D conversion does not start. Therefore, first turn on 'Operating condition setting
request' (Y9), check the off state of 'Operating condition setting completed flag' (X9), and turn off 'Operating condition setting request'
(Y9).
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.
4 TROUBLESHOOTING
78
4.3 Troubleshooting by Symptom
Action
(1) Wire the cables by referring to the external wiring described in the manual. (
MELSEC iQ-R HART-Enabled Analog-Digital Converter Module User's Manual
(Startup))
(2) Supply 24VDC within the range of the performance specifications. ( MELSEC iQ-R
HART-Enabled Analog-Digital Converter Module User's Manual (Startup))
The possible cause is a failure of the A/D converter module. Please consult your local
Mitsubishi representative.
Action
Use the solderless terminals having specifications described in the manual. (
MELSEC iQ-R HART-Enabled Analog-Digital Converter Module User's Manual (Startup))
Refer to the external wiring example and check and correct the wiring.
( MELSEC iQ-R HART-Enabled Analog-Digital Converter Module User's Manual
(Startup))
Identify the faulty area of signal wires by a visual check and continuity check.
Consider voltage drop across the external power supply and the HART-enabled device
when supplying power to the HART-enabled device from the A/D converter module.
Check the voltage drop across the A/D converter module and the HART-enabled device
to ensure that the sufficient voltage is supplied to the HART-enabled device by referring to
the manual below.
 MELSEC iQ-R HART-Enabled Analog-Digital Converter Module User's Manual
(Startup)
Action
Check "Input range setting" of the module parameter and configure the setting again if the
setting is incorrect.
Check 'CH1 Range setting' (Un\G598) using the monitor functions of the engineering tool
("Device/Buffer Memory Batch Monitor" or "Intelligent Function Module Monitor"). If the
set value is incorrect, correct the value with the engineering tool or a program.
Turn on and off 'Operating condition setting request' (Y9)
check that a digital output value is stored in 'CH1 Digital output value' (Un\G400).
If the stored value is correct, further check the program to verify the description of
'Operating condition setting request' (Y9).
Action
To reduce noise, take measures such as the use of shielded cables for
connection.
*1
with the engineering tool and