BACnetStack_SetIntrinsicChangeOfBitstringAlgorithm64

bool BACnetStack_SetIntrinsicChangeOfBitstringAlgorithm64(
  const uint32_t deviceInstance,
  const uint16_t objectType,
  const uint32_t objectInstance,
  const uint32_t bitmaskLow,
  const uint32_t bitmaskHigh,
  const uint32_t alarmValueLow,
  const uint32_t alarmValueHigh,
  const uint32_t bitstringLength,
  const uint32_t timeDelay,
  const bool useTimeDelayNormal,
  const uint32_t timeDelayNormal,
  const bool enable);

Enables the CHANGE_OF_BITSTRING algorithm for a bit string of up to 64 bits.

The object must exist and have alarms and events enabled by BACnetStack_SetAlarmsAndEventsForObjectEnabled(…, enabled=true) - an Event Enrollment object carries its own and needs no such call; otherwise this returns false.

Sibling of BACnetStack_SetIntrinsicChangeOfBitstringAlgorithm() above that reaches all 64 bits the engine actually holds - that export’s bitmask/alarmValue are each a single uint32_t and can only ever express bits 0-31 of the monitored bitstring. This export splits both into (Low, High) uint32_t halves: bit i of *Low is bit i of the bitstring (i = 0..31), bit i of *High is bit (i+32) of the bitstring (i = 0..31) - together they can express bits 0-63.

Multiple alarm values (cl. 13.3.1 defines pAlarmValues as a LIST) are still not supported by this export - it sets exactly one alarm value, the same deviation as the 32-bit export above.

BACnet reference: ANSI/ASHRAE 135-2024 clause 13.3.1 (CHANGE_OF_BITSTRING Event Algorithm).

Parameters

Parameter	Direction	Description
`deviceInstance`	in	The instance number of the device that owns this object.
`objectType, objectInstance`	in	The object for alarms and events: one BACnet Object Identifier, carried as two parameters (see the API conventions).
`bitmaskLow, bitmaskHigh`	in	Packed-uint32 halves of the significant-bits mask (cl. 13.3.1 pBitmask). Bit i of bitmaskLow is bit i of the bitstring; bit i of bitmaskHigh is bit (i+32).
`alarmValueLow, alarmValueHigh`	in	Packed-uint32 halves of the alarm value, same bit order, compared against (monitored AND bitmask).
`bitstringLength`	in	The number of significant bits in the monitored bitstring. MUST be 1..64 - 0 is rejected (see the 32-bit export’s doc for why) and a value above 64 is rejected; the call returns false and changes nothing.
`timeDelay`	in	The time delay for the transition to the OFFNORMAL state.
`useTimeDelayNormal`	in	Whether to use a separate timeDelayNormal for the to-normal transition.
`timeDelayNormal`	in	The time delay for the transition back to the NORMAL state.
`enable`	in	Initial inhibit state, inverted - see the 32-bit export’s doc above for the full explanation. Recommended value: true.

Returns

True on success; false if the device or object does not exist, the object type does not support this algorithm, bitstringLength is out of range, or Alarm-and-Event support was not compiled (STACK_OPTION_ALARMS_AND_EVENTS).

Topic: Alarms and events. Declared in CASBACnetStackDLL.h.