Processing Faults

The following table describes how the instruction handles execution faults:
Fault Condition
Action
CVFaulted
or
CVEUSpanInv
is set
  • Instruction is not initialized, CVInitializing is cleared.
  • Compute PV and SP percent, calculate error, update internal parameters for EPercent and PVPIDPercent
  • PID control algorithm is not executed.
  • Disable the Auto and Cascade/Ratio modes. If Override or Hand is not the current mode, set to Manual mode.
  • Set CV to value determined by Program or Operator control and mode (Manual, Override, or Hand).
CVinitRequest
Refer to Execution.
PV Health Bad
  • Disable the Auto and CasRat modes. If Override or Hand is not the current mode then set to the Manual mode.
  • Set PV high-low, PV rate-of-change, and deviation high-low alarm outputs FALSE
  • PID control algorithm is not executed.
  • Set CV to value by determined by Program or Operator control and mode (Manual, Override or Hand).
PVFaulted is set
  • Disable the Auto and Cascade/Ratio modes. If Override or Hand is not the current mode, set to Manual mode.
  • PV high-low, PV rate-of-change, and deviation high-low alarm outputs are cleared
  • PID control algorithm is not executed.
  • Set CV to value by determined by Program or Operator control and mode (Manual, Override, or Hand).
PVSpanInv is set or SPLimitsInv is set
  • Disable the Auto and Cascade/Ratio modes. If Override or Hand is not the current mode, set to Manual mode.
  • Do not compute PV and SP percent.
  • PID control algorithm is not executed.
  • Set CV to value by determined by Program or Operator control and mode (Manual, Override, or Hand).
RatioLimitsInv is set and CasRat is set and UseRatio is set
  • If not already in Hand or Override, set to Manual mode.
  • Disable the Cascade/Ratio mode.
  • Set CV to value determined by Program or Operator control and mode (Manual, Override, or Hand).
TimingModeInv is set or RTSTimeStampInv is set or DeltaTInv is set
  • If not already in Hand or Override, set to Manual mode.
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