The errors in the PLC can be categorized as below:
1.CPU error:
a. System watchdog Reset (WDT Error)
If there is error in this category the CPU error flag ( MW01_0 device) sets along with corresponding device of the error. So for WDT error MW01_11 device sets.
2.I/O Error:
a.I/O mismatch error
b.I/O bcc error.
If there is error in this category the I/O error flag ( MW01_1 device) sets along with corresponding device of the error. So for I/O mismatch error MW01_13 device sets and for I/O bcc error MW01_15 device sets.
3.Program Error:
a. Scan Time Over error
If there is error in this category the I/O error flag ( MW01_2 device) sets along with corresponding device of the error. So for Scan Time Over error MW02_1 device.
4.Other Errors:
a.Clock calendar error
b.Retentive Data Loss error
For Clock calendar error MW01_5 device sets and for Retentive Data Loss error MW01_6 device sets
Above error conditions are checked either in each main loop scan or only at power up. This is mentioned in the following table.
The configuration devices (M) and configuration registers (MW) are used for special purposes.
Error Messages and related information:
No.Event | Info1 | Info 2 | Info 3 | Info 4 Special | Meaning and | Check at | |
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| Device | countermeasures |
|
1 | Retentive |
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| MW01_6 | In the | Only |
| Data Loss |
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| data invalidity of RAM (back- |
|
| Error |
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| up area) has been detected. |
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| If retentive registers are used, |
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| these validity are not guarant- |
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| eed. (No error down) |
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2 |
|
|
| MW01_5 | The data of | Only | |
| endar error |
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| LSI is illegal.(No error down) |
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| Set the date and time. |
|
4 | I/O | slot | Unit |
| MW01_1 | The I/O allocation information | Only |
| mismatch | No. | Type |
| MW01_13 | and the actual I/O configuration |
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| are not identical.(Error down) |
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| Check the I/O allocation and |
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| the option card mounting status |
|
5 | I/O BCC |
| Unit | Register | MW01_1 | I/O bus parity error has been | Each main loop |
| error |
| No. | No. | MW01_15 | detected in data read/write for | scan |
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| I/O modules. An abnormality |
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| has been detected in I/O bus |
|
checking. (Error down)I/O No answer. (Error down) Check the expansion cable connect- ion and the I/O module mounting status.
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