[CMN_EVT] Common event

Function block CMN_EVT reads the present value and additional properties of a common event object.

CMN_EVT reads the present value and additional properties of a common event object.

Functioning

Compatible data points:

  • Common event [CmnEvt]

Required properties:

  • Present value
  • Status flag
  • Alarm object count
  • Fault object count
  • Extended fault object count
  • Unacknowledged fault object count

Optional properties:

  • Reliability
  • Event state
  • Extension by event configuration
  • Acknowledged transitions
  • Suppress event notification
  • Suppress event detection
  • Acknowledge.
Pins

Input

Description

Data type

Default value
Value range

SupEvtDet

Suppress event detection

Suppresses the detection of events.
Note
If the extension for 'Intrinsic reporting' is not enabled, the input value is not considered in the function of the function block.
If the same BACnet object is accessed by multiple functions in a control program, only one of these function blocks may interconnect to the pin.
The function is not available for BACnet third-party objects.

Boolean

0

SupEvtNtf

Suppress event notification

Suppresses notification of events.
Note
If the extension for 'Intrinsic reporting' is not enabled, the input value is not considered in the function of the function block.
If the same BACnet object is accessed by multiple function blocks in the control program, only one of these function blocks may interconnect to the pin.
The function is not available for BACnet third-party objects.

Boolean

0

Ack

Acknowledge

Permits acknowledgement of any unacknowledged transition for BACnet object in the scope of the referenced BACnet objects.
The function is not available for BACnet third-party objects.

Boolean

0

BaObjRef

BA-Object reference
Link between function block and BACnet object.

Structure

---

BaObjRef
> DeviceID

Device identifier
[DeviceID] includes object type and object instance in one ID.
Identifies the device object: local or remote. A local device object can also be identified by value 16#3FFFFF.

Double Word

16#3FFFFF

BaObjRef
> ObjectID

Object identifier
[ObjectID] includes object type and object instance in one ID.
Identifies the object on a device.

Double Word

16#3FFFFF

BaObjRef
> ItemID

Item identifier
[ItemID] represents an index in a view node object that references the BACnet object.
[ObjectID] and [ItemID] together define an indirect reference to the BACnet object.
Value -1 indicates a direct interface.

Integer

-1

 

Output

Description

Data type

Default value
Value range

PrVal

Present value

Value of property 'Present value' for the referenced BACnet object.

Integer

1

Dstb

Disturbed

[Dstb] indicates whether the referenced BACnet object is in fault or in state OffNormal. When the BACnet object returns to state Normal, [Dstb] retains its value until the transition to normal is acknowledged.
[Dstb] = 1, if:
BACnet object = Access error
OR
'Status flag' = Fault
OR
'Event state' <> Normal

[Dstb] = 0, if the above condition is not fulfilled AND 'Acknowledged transitions' = x, x, 1.

Note
Properties 'Event state' and 'Acknowledged transitions' are not considered if the BA-Object has an alarm extension set to disabled.
Output [Dstb] does not retain the value after a restart following a power outage if the state of the BACnet object is normal.
Properties 'Event state' and 'Acknowledged transitions' are not considered on BACnet third-party objects.

Boolean

0

Flty

Faulty

[Flty] indicates whether the last event on the referenced BACnet object was in fault. If the BACnet object returns to the normal state, [Flty] retains its value until the transition to normal is acknowledged.
[Flty] = 1, if:
BACnet object = Error during access
OR
'Status flag' = Fault

[Flty] = 0, if the above condition is not fulfilled AND one of the following possibilities is valid:

  • 'Event state' = Offnormal
  • OR
  • 'Event state' = Normal AND 'Acknowledged transitions' = x, x, 1

Note
Properties 'Event state' and 'Acknowledged transitions' are not considered if the BA-Object has an alarm extension set to disabled.
Output [Flty] does not retain the value upon restart after a power outage if the state of the BACnet object is normal.
Properties 'Event state' and 'Acknowledged transitions are not considered for BACnet third-party objects.

Boolean

0

OffNrml

Offnormal

[OffNrml] indicates whether the last event on the reference BACnet object was Offnormal. When the BACnet object returns to state Normal, [OffNrml] retains its value until the transition to normal is acknowledged.
[OffNml] = 1, if:
BACnet object = Access successful
AND
'Status flag' = No fault
AND
'Event state' = Offnormal

[OffNml] = 0, if the above condition is not fulfilled OR 'Event state' = Normal AND 'Acknowledged transitions' = x, x, 1.

Note
Properties 'Event state' and 'Acknowledged transitions' are not considered if the BA-Object has an alarm extension set to disabled.
Output [OffNml] does not retain the value after a restart following a power outage if the state of the BACnet object is normal.
The function is not available for BACnet third-party objects.

Boolean

0

Rlb

Reliability
Indicates the value of property 'Reliability', if the property is available.

Integer

0: No fault detected

EvtInd

Event indication

Indicates if BACnet objects in state Fault or Offnormal are included within the scope of the referenced BACnet object.

Boolean

0

0 – No BACnet objects with Fault or Offnormal are part of the scope.
1 – BACnet objects with Fault or Offnormal are part of the scope.

NewEvt

New event

Indicates if a BACnet object transitioning to state Fault or Offnormal is included within the scope of the referenced BACnet object.
The output is set to 1 for one cycle.

Note
The output is not set to 1 in the following cases:

  • A BACnet object within the scope transitions from state Fault or Offnormal to another state Fault or Offnormal.
  • In the same cycle, one BACnet object transitions to state Normal and another to state Fault or Offnormal.
  • BACnet objects in state Fault or Offnormal exist at startup.
  • A new BACnet object transitions to state Fault or Offnormal within the scope of a nested plant component with common event.

Boolean

0

AckSta

Acknowledged state

Indicates if the scope of the referenced BACnet object includes unacknowledged transition.

Boolean

0

0 - No BACnet objects with unacknowledged transitions
1 - BACnet objects with unacknowledged transitions

ErrCode

Error code indication

Integer

0: No error

= 0 - No error
> 0 - XFB error codes