BacnetNumericValue Function Block
The BacnetNumericValue exposes a raw object over BACnet as ‘Analog Value’ BACnet object.
Figure 1:BacnetNumericValue - Function Block |
Figure 2:BacnetNumericValue - Property Sheet |
Input
Input Name |
Description |
In |
It is a 32-Bit floating input point. |
Fail Detect Enable |
0: Disable 1: Enable Set it to true to enable the fail detection feature. Note: This feature enables the monitoring of periodic updates of a function block over a network. |
Fail Detect Fallback Value Select |
0: InvalidValue 1: LastknownGoodValue 2: FixedValue InvalidValue: Out is set as NULL LastknownGoodValue: If the last Out value was not NULL, then Out is retained as it is; otherwise, a value from the Default Value parameter goes to Out. FixedValue: Fail Detect Fixed Value goes to Out |
Fail Detect Fallback Value |
Define the value that should be set to Out (when failure is detected), when Fail Detect Enable is True, and Fail Detect Fallback Value is set to Fixed Value. It is a 32-bit floating point value. |
Fail Detect Delay |
Update interval in seconds within which Present Value should get written over BACnet periodically. Present Value not written within this interval will result in failure, and Out will be set with the value as configured in Fail Detect Fallback Value Select. It is a 32 bit integer value with a range of 0 to 3600 sec. |
Table 1:Inputs of BacnetNumericValue Function
Output
Output Name |
Description |
Out |
When Out of Service is "false" - Out is same as In, if In is connected and its value is not NULL. When In is NULL, Out take value from Default Value parameter. This value will also be exposed as Present Value over BACnet. Out will change when Present Value is changed over BACnet or Default Value parameter is changed via Tool. When Out of Service is "true" - Out is decoupled from In. Out is the Present Value written over BACnet. |
Status Flags |
Displays the status of this function block. It can be 0 or the following value. 2 - Fault 8 - Out of Service Example: A value of 8 means the function block is in Out of Service state. A value of 2 means the function block is in Fault state. A value of 0 means the function block is not in Out of Service state. |
Event State |
Displays the present event state of this function block. It will always be in the following state- 0-Normal |
Out Of Service |
It shows 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 ‘In’ from ‘Out’, i.e. ‘In’ values no longer show up on ‘Out’. When ‘Out of Service’ is "true", ‘Out’ can be overwritten over BACnet (via Present Value property). |
Table 2:Outputs of BacnetNumericValue 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. |
Default Value |
Define the value that shows up on Out at controller startup, when In is not connected. |
Bacnet Object Instance |
It shows the instance number of this BACnet object function block. |
Fail Detect |
Fail Detect only works if In is NULL and Fail Detect Enable is set to "true". Fail Detect Time - Update interval in seconds within which Present Value should get written over BACnet periodically. Present Value not written within this interval will result in failure and Out will be set with the value as configured in Fallback Value. Fail Detect Value: Select the Fail Detect Value type.
Enable - Set it to true to enable fail detection feature. Note - This feature enables monitoring of periodic update of a function block over network. |
Fail Detect Fixed value |
Define the value that should be set to Out (when failure is detected), if Fail Detect Enable is "true" and Fail Detect Fallback Value is set to "Fixed Value". |
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. If the present value is changed via BACnet , then the same value will be set to present value after power cycle. If there is no value saved then first time it will use the default value Out: To enable or disable the Out feature. |
Table 3:Parameters of BacnetNumericValue Function
Examples
Figure 3:Example - BacnetNumericValue Function Block
Figure 4:Example - BacnetNumericValue Property Sheet
Refer to General Description for general information about IRMN4 Function Blocks.