Hsc micrologix 1500

Program File Number (PFN)

The PFN (Program File Number) variable defines which subroutine is called
(executed) when HSC0 counts to High Preset or Low Preset, or through Overflow or Underflow. The integer value of this variable defines which program file will run at that time. A valid subroutine file is any program file (3 to 255). See also:Interrupt Latency on page 236.​

HSC Error Codes:​

Error Code Name Mode
1 Invalid File Number: Interrupt (program) file identified in HSC:0.PFN is less than 3, greater than 255, or does not exist.
2 Invalid Mode Invalid Mode
3 Invalid High Preset: 0,1 High preset is less than or equal to zero (0), 2 to 7 High preset is less than or equal to low preset.
4 Invalid Overflow: 0 to 7 High preset is greater than overflow.
(1) For Mode descriptions, see HSC Mode (MOD) on page 101.

Faults are classified as recoverable, non-recoverable, and non-user faults. A complete list of faults is shown in Fault Messages and Error Codes on page 413. The basic types of faults are described below:
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Recoverable, Non-Recoverable, Non-User Fault.​

Controller Operation​

The occurrence of recoverable or non-recoverable faults causes the controller to read S:29 and execute the subroutine number identified by S:29. If the fault is recoverable, the routine can be used to correct the problem and clear the fault bit S:1/13. The controller then continues in its current executing mode. The routine does not execute for non-user faults.​

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