BACnet.Protocol.FaultAlgorithms.FaultState (bacstack v0.0.1)

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Represents the BACnet fault algorithm FaultState.

The FAULT_STATE fault algorithm detects whether the monitored value equals a value that is listed as a fault value. The monitored value may be of any discrete or enumerated datatype, including Boolean. If internal operational reliability is unreliable, then the internal reliability takes precedence over evaluation of the monitored value.

For more specific information about the fault algorithm, consult ASHRAE 135 13.4.5.

Summary

Types

t()

Representative type for the event algorithm.

Functions

execute(state)

Calculates the new state for the current state and parameters. Prior to this function invocation, the state should have been updated with update/2, if any of the properties has changed.

new(monitored_value, params)

Creates a new algorithm state.

update(state, params)

Updates the state using the given parameters (monitored_value, parameters).

Types

t()

@opaque t()

Representative type for the event algorithm.

Functions

execute(state)

@spec execute(t()) ::
  {:event, new_state :: t(),
   new_reliability :: BACnet.Protocol.Constants.reliability()}
  | {:no_event, new_state :: t()}

Calculates the new state for the current state and parameters. Prior to this function invocation, the state should have been updated with update/2, if any of the properties has changed.

ASHRAE 135:

The conditions evaluated by this fault algorithm are:

(a) If pCurrentReliability is NO_FAULT_DETECTED, and pMonitoredValue is equal to any of the values in pFaultValues, then indicate a transition to the MULTI_STATE_FAULT reliability.

(b) If pCurrentReliability is MULTI_STATE_FAULT, and pMonitoredValue is not equal to any of the values contained in pFaultValues, then indicate a transition to the NO_FAULT_DETECTED reliability.

(c) Optional: If pCurrentReliability is MULTI_STATE_FAULT, and pMonitoredValue is equal one of the values contained in pFaultValues that is different from the value that caused the last transition to MULTI_STATE_FAULT, then indicate a transition to the MULTI_STATE_FAULT reliability.

new(monitored_value, params)

@spec new(
  BACnet.Protocol.PropertyState.t(),
  BACnet.Protocol.FaultParameters.FaultState.t()
) :: t()

Creates a new algorithm state.

update(state, params)

@spec update(t(), Keyword.t()) :: t()

Updates the state using the given parameters (monitored_value, parameters).