BacnetNumericOutput Function Block

The BacnetNumericOutput exposes a raw object over BACnet as 'Analog Output' BACnet object.

Figure 1: BacnetNumericOutput Function Block

Figure 2: BacnetNumericOutput Property Sheet

Input

Input Name

Description

In 15

It is a 32-Bit floating input point.

Table 1: Inputs of BacnetNumericOutput Function

Output

Output Name

Description

Present Value

Displays the highest priority valid value from Priority Array.

BacnetNumericOutput maintains a Priority Array of size 16, exposed over BACnet.

Index 1 being the highest and index 16 being the lowest.

In15 value shows up at Priority Array Index 15.

The Rest of the Index/Priority values can be updated over BACnet.

Present Value always reflects the first highest priority (from 1 to 16) valid value (not NULL).

Out

When Out of Service is false - Out is same as Present Value.

When Out of Service is true - Out retains the last value it had before Out Of Service was set to true.

Status Flags

Displays the status of this function block. It can be any one or a 'OR' combination of the following values:

1 - In Alarm

2 - Fault

4 - Overwritten

8 - Out of Service

Example:

A value of 1 means the function block is in In Alarm state.

A value of 9 means the function block is in 'Out of Service' as well as in In Alarm state.

Event State

Displays the present event state of this function block. It can be any one of the following values:

0 - Normal

1 - Fault

3 - High Limit

4 - Low Limit

Out of Service

It shows the whether the function block is in out of service state or not.

Out of Service is modifiable over BACnet. Setting Out Of Service to true, decouples Present Value from Out, i.e. Present Value value no longer shows up on Out.

When Out Of Service is true, Out will retain its last value that it had before Out Of Service was set to true.

Table 2: Output of BacnetNumericOutput Function

Parameter

Parameter Name

Description

Units

Define the Out value's engineering unit.

Cov Increment

Define the delta value change in Out, that will trigger COV update notifications to other recipients on the BACnet bus.

Relinquish Default

Define the value that shows up on Out when 'In15' is not connected and priority array doesn't have any valid value.

Time Delay

Define the time delay (in seconds) with which a High Limit/Low Limit/Normal transition will be set off, once conditions are met.

Notification Class

Define the notification class, from one of the following:

  • Urgent
  • High
  • Low
  • User Defined

High Limit

Define the high limit.

When Limit Enable High Limit is defined true, if Out value exceeds this limit and the condition exists for at least the defined Time Delay period, then:

  • Event State is changed to High Limit.
  • Status Flags is set to In Alarm.
  • An event notification is sent to all recipients listed by the Notification Class (if Event Enable to Off Normal is defined true).

Low Limit

Define the low limit.

When Limit Enable Low Limit is defined true, if Out value falls below this limit and the condition exists for at least the defined 'Time Delay' period, then -

  • Event State is changed to Low Limit.
  • Status Flags is set to In Alarm.
  • An event notification is sent to all recipients listed by the Notification Class (if Event Enable to Off Normal is defined true).

Deadband

Define the value of the dead-band.

While transitioning from an off normal state (High Limit/Low Limit) to Normal state Out value must remain between the range - (Low Limit' + Deadband) and (High Limit - Deadband), for at least the defined 'Time Delay' period, then only -

  • 'Event State' is changed to 'Normal'.
  • 'Status Flags' is cleared-off of 'In Alarm'.
  • An event notification is sent to all recipients listed by the 'Notification Class' (if Event Enable To Normal is defined true).

Limit Enable Low Limit

Setting it to true, enables detection of low limit alarm based on configured Low Limit value.

Limit Enable High Limit

Setting it to true, enables detection of high limit alarm based on configured Hight Limit value.

Event Enable to Off Normal

Setting it to true, enables sending of event notification of Off-Normal event transitions to recipients listed by the Notification Class over BACnet.

Event Enable to Fault

Setting it to true, enables sending of event notification of Fault event transitions to recipients listed by the Notification Class over BACnet.

Event Enable to Normal

Setting it to true, enables sending of event notification of Normal event transitions to recipients listed by the Notification Class over BACnet.

Notify Type

Define one of the two notify types:

Event Detection Enable

Setting it to true enables:

  • Detection of High Limit/Low Limit/Fault/Normal events in Event State.
  • Setting/Resetting of In Alarm/Fault/Overwritten/Out of Service flags in Status Flags.

If it is set to false:

  • Event State will always remain Normal.
  • Status Flags will always remain 0.

Bacnet Object Instance

It shows the instance number of this BACnet object function block.

Out Save

Master Sync Enabled: If you set it to "true" the last output will be set as output for one cycle after the controller restarts. The application can use it to return to the same state before the controller restart

Out: To enable or disable the Out feature.

Present Value: To enable or disable the Present value feature.

Note: The Out Save feature is only configurable via tools for Present Value and Out slot. As a result, after a power cycle, BACnet Output loses its priority array values, but the most recent OUT/Present Value is retained and appears on Priority Slot 16. This value, which belonged to which priority index prior to the power cycle event, will be lost.

Table 3: Parameters of BacnetNumericOutput Function

Examples

Figure 3: Example - BacnetNumericOutput Function Block

Refer to General Description for general information about IRMN4 Function Blocks.