SLC 500 PLC Major Error Codes
Allen Bradley SLC 500 Errors
SLC 500 Major Error Codes can be found in: Processor Status in RSLogix 500 Data File S2 Status Errors S:6 = xxxxh (hex 0 to FFFF)
Whenever major error is encountered bit S:1/13 – Major Error Halted Bit is set.
S:54 – Last Major Error Fault Code mirrors the last error code value stored in S:6 register.
Major errors in S:6 or S:54 registers contain four (4) digits in hexadecimal code, however RSLogix 500 software do not display leading „0”.
E.g. error code 0001h is displayed as 1h.
Major Faults can be classified as:
Non-user – a fault caused by various conditions that cease ladder program execution. The user-fault routine is not run when this fault occurs.
Non-recoverable – a fault caused by the user that cannot be recovered from. The user-fault routine is run when this fault occurs. However, the fault cannot be cleared.
Recoverable – a fault caused by the user that can be recovered from in the user-fault routine by resetting Major Error Halted Bit(S:1/13). The user-fault routine is run when this fault occurs.
Major Error categories are:
- powerup errors
- going-to-run errors
- runtime errors
- user program instruction errors
- I/O errors
First two digits have different meaning for Powerup, Going-to-run and Run errors (range 0001h-003Ch and 005Fh) than for I/O Errors (range xx50h-xx94 and 0x00A0-0x00A2).
For Powerup, Going-to-run and Run errors first two digits are 00 or define file number.
For I/O Errors first two digits define slot number:
- 00 mean slot 0
- 1E mean slot 30
- 1F mean slot cannot be determined.
- 03 is special – for modular SLC controller it mean slot 3 but for compact SLC controller it mean slot cannot be determined.
E.g. Error code 250h (0250h) – A chassis data error is detected for module in slot 2