Setpoint High Alarm

What does SPHAlarm mean?

This alarm indicator is set to true when the current Setpoint (SP) value exceeds the configured Setpoint High Limit (SPHLimit). This indicates that the SP is attempting to go above its allowable maximum. In the PIDE instruction, this alarm is not evaluated if the SP limits configuration (SPLimitsInv) is invalid. In the PPID instruction, it is not evaluated if SP is not held by shed (Sts_SPHeld=0), SP is not set to interlock SP by shed (Sts_IntlkSP=0), or if SP clamping limits are invalid (Sts_ErrSPLim=0 implies valid, so Sts_ErrSPLim=1 would be invalid).

• Setpoint (SP) value has exceeded the configured SPHLimit.
• Invalid SP limits configuration (SPLimitsInv) in the PIDE instruction.
• SP is held by shed (Sts_SPHeld=1) or set to interlock SP by shed (Sts_IntlkSP=1) in the PPID instruction, combined with a high SP.
• Invalid SP clamping limits (Sts_ErrSPLim=1) in the PPID instruction.
• Process demands requiring a setpoint beyond the safe operating limit.

Click steps to track your progress.

1. 1

   Verify the current Setpoint (SP) value and the configured Setpoint High Limit (SPHLimit) within the Logix 5000 controller's program.

2. 2

   Inspect the configuration of the SPHLimit parameter in the PIDE/PPID instruction block to ensure it is set to an appropriate and valid value.

3. 3

   Check the status of the SPLimitsInv tag (for PIDE) or Sts_ErrSPLim tag (for PPID) within the instruction block to determine if the SP limits configuration is considered invalid.

4. 4

   For PPID instructions, examine the Sts_SPHeld and Sts_IntlkSP statuses to understand if the setpoint is held or interlocked, as this affects alarm evaluation.

5. 5

   Analyze the control logic that drives the Setpoint (SP) value to understand why it is attempting to exceed the SPHLimit.