Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
D-22
6 Troubleshooting
6.5 Program Check
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3G
-2AD-BD (2-channel analog Input)
4. Error status
Check that no error is detected in the 2AD-BD.
If an error is detected, check the details of the error, and then check the wiring and programs.
If an error is detected, check the details of the error, and then check the wiring and programs.
→ For a detailed description of special devices, refer to Chapter 4.
6.5
Program Check
Check the following items for the program:
1. Clearing of error status at power on
When the power is turned off and then on again, the error status should be cleared (b6 and b7 should turn off)
using the program.
using the program.
2. Check of storage devices
Verify that different values are not being stored in the same device by other parts of the program.
6.6
Error Status Check
If an error occurs in the 2AD-BD, the corresponding bit will turn on.
To solve the problem, refer to the troubleshooting method described below:
1. Over-scale detection (b0, b1)
1) Description of error
The input analog value (voltage or current value) is outside the specified range.
The digital value is out of the range specified for the voltage input mode (0 to 4080) or outside the range
specified for the current input mode (0 to 2040).
The digital value is out of the range specified for the voltage input mode (0 to 4080) or outside the range
specified for the current input mode (0 to 2040).
2) Remedy
Check that the input analog value is within the specified range. Also check the wiring.
2. EEPROM error (b4)
1) Description of error
The adjustment data which was set in the EEPROM before delivery from our factory cannot be read out
properly or has been destroyed.
properly or has been destroyed.
2) Remedy
Please contact the nearest Mitsubishi Electric distributor office.
3. Averaging time setting error (b5)
1) Description of error
The averaging time set for one of the channels (channels 1 to 2) is outside the specified range: 1 to 4095.
2) Remedy
Check that the averaging time is set correctly for each channel.
4. 2AD-BD hardware error (b6)
1) Description of error
The 2AD-BD is not operating properly.
2) Remedy
Check that the 2AD-BD is correctly connected to the PLC.
If the problem cannot be solved even after the above check, please contact the nearest Mitsubishi
Electric distributor office.
If the problem cannot be solved even after the above check, please contact the nearest Mitsubishi
Electric distributor office.
Bit
Description
Bit
Description
b0
Channel-1 over-scale detection
b5
Averaging time setting error
b1
Channel-2 over-scale detection
b6
2AD-BD hardware error
b2
Unused
b7
2AD-BD communication data error
b3
Unused
b8 to b15 Unused
b4
EEPROM error
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