Integer Value
An Integer Value object holds a signed whole number. A device uses it for counts, offsets, temperatures in whole degrees or any setting that can go negative. A client reads it, and it can be made writable or commandable.
Typical uses
Section titled “Typical uses”- Hold a signed temperature offset
- Expose a net energy balance that can go negative
- Report an error count from a controller
- Accept a numeric setting from an operator
Key properties
Section titled “Key properties”| Property | What it holds |
|---|---|
| Present_Value | The current signed integer value. |
| Units | The engineering units of the value. |
| COV_Increment | How far the value must move before a change-of-value notice is sent. |
| Min_Pres_Value | The lowest value the object accepts. Optional. |
| Max_Pres_Value | The highest value the object accepts. Optional. |
| Resolution | The smallest change the underlying value can show. Optional. |
How it behaves
Section titled “How it behaves”An Integer Value is a plain value unless it has a priority array and a relinquish default, in which case clients command it with prioritised writes. Where it reports events itself, the standard pairs it with the SIGNED_OUT_OF_RANGE algorithm, which raises an alarm when the value goes outside low and high limits. It sends change-of-value notices when the value moves by COV_Increment.
With the CAS BACnet Stack
Section titled “With the CAS BACnet Stack”Enable it with the STACK_OPTION_OBJECT_TYPE_INTEGER_VALUE build option and add each object with BACnetStack_AddObject. Serve Present_Value with the callback you register with BACnetStack_RegisterCallbackGetPropertySignedInteger, and accept writes with the BACnetStack_RegisterCallbackSetPropertySignedInteger callback. It becomes commandable when you enable both PriorityArray and RelinquishDefault with BACnetStack_SetPropertyEnabled; the stack then reads the priority array through your callbacks instead of calling the plain Present_Value callback, as the BACnetStack_AddObject page describes. Arm limit alarms with BACnetStack_SetAlarmsAndEventsForObjectEnabled and then BACnetStack_SetIntrinsicSignedOutOfRangeAlgorithm. The stack has no fault out-of-range setter for this type: BACnetStack_SetFaultOutOfRangeAlgorithmReal refuses it.
Related object types
Section titled “Related object types”Positive Integer Value, Analog Value, Large Analog Value
Properties
Section titled “Properties”The properties ASHRAE 135-2024 clause 12.43 defines for this object type.
How to read the table:
- Conformance is what the standard asks of every object of this type: R is required, W is required and writable by a client, O is optional. A digit after the letter marks a condition in the standard that decides when the property is present or writable, such as support for intrinsic reporting.
- Present by default: yes means the stack presents the property as soon as you add the object; no means it
is optional and you turn it on with
BACnetStack_SetPropertyEnabled. This is the stack’s starting setup, so it can differ from the conformance code. - Writable is whether a client can write the property by default. Change it with
BACnetStack_SetPropertyWritable. - not in profile means the stack does not offer this property for this object type.
- Value when your callback does not answer: “Held by the stack” means the stack stores and serves the value itself and does not ask your callbacks. Otherwise it is the value the stack answers when your callback declines or is not registered.
| Property | Datatype | Conformance | Present by default | Writable | Value when your callback does not answer |
|---|---|---|---|---|---|
| Object_Identifier | BACnetObjectIdentifier | R | yes | no | Held by the stack. |
| Object_Name | CharacterString | R | yes | no | "Object <type>,<instance>", such as "Object 0,1" for Analog Input 1. |
| Object_Type | BACnetObjectType | R | yes | no | Held by the stack. |
| Description | CharacterString | O | no | no | "" |
| Present_Value | Integer | R1 | yes | no (yes while Out_Of_Service is true) | No default: value-not-initialized. Once Priority_Array and Relinquish_Default are enabled, built by the stack from the priority array your callbacks serve. |
| Status_Flags | BACnetStatusFlags | R | yes | no | Built by the stack from your callbacks. |
| Event_State | BACnetEventState | O4 | no | no | 0 |
| Reliability | BACnetReliability | O | no | no (yes while Out_Of_Service is true) | 0 |
| Out_Of_Service | Boolean | O | no | no | false |
| Units | BACnetEngineeringUnits | R | yes | no | 95 (no units) |
| Priority_Array | BACnetARRAY[16] of BACnetOptionalInteger | O2 | no | no | Built by the stack from your callbacks. |
| Relinquish_Default | Integer | O2 | no | no | No default: value-not-initialized until a callback or a client write supplies one. |
| COV_Increment | Unsigned | O3 | no | no | 0 |
| Time_Delay | Unsigned | O4,6 | no | no | 0 |
| Notification_Class | Unsigned | O4,6 | no | no | 0 |
| High_Limit | Integer | O4,6 | no | no | 0 |
| Low_Limit | Integer | O4,6 | no | no | 0 |
| Deadband | Unsigned | O4,6 | no | no | 0 |
| Limit_Enable | BACnetLimitEnable | O4,6 | no | no | An empty bit string. |
| Event_Enable | BACnetEventTransitionBits | O4,6 | no | no | An empty bit string. |
| Acked_Transitions | BACnetEventTransitionBits | O4,6 | no | no | An empty bit string. |
| Notify_Type | BACnetNotifyType | O4,6 | no | no | 0 |
| Event_Time_Stamps | BACnetARRAY[3] of BACnetTimeStamp | O4,6 | no | no | No default: the read fails. |
| Event_Message_Texts | BACnetARRAY[3] of CharacterString | O6 | no | no | "" |
| Event_Message_Texts_Config | BACnetARRAY[3] of CharacterString | O6 | no | no | "" |
| Event_Detection_Enable | Boolean | O4,6 | no | no | false |
| Event_Algorithm_Inhibit_Ref | BACnetObjectPropertyReference | O6 | no | no | No default: the read fails. |
| Event_Algorithm_Inhibit | Boolean | O6,7 | no | no | false |
| Time_Delay_Normal | Unsigned | O6 | no | no | 0 |
| Reliability_Evaluation_Inhibit | Boolean | O8 | no | no | false |
| Min_Pres_Value | Integer | O | no | no | 0 |
| Max_Pres_Value | Integer | O | no | no | 0 |
| Resolution | Integer | O | no | no | 0 |
| Property_List | BACnetARRAY[N] of BACnetPropertyIdentifier | R | yes | no | Held by the stack. |
| Fault_High_Limit | Integer | O9 | no | no | 0 |
| Fault_Low_Limit | Integer | O9 | no | no | 0 |
| Current_Command_Priority | BACnetOptionalUnsigned | O2 | no | no | Built by the stack from your callbacks. |
| Value_Source | BACnetValueSource | O10,12,14 | no | no | No default: the read fails. |
| Value_Source_Array | BACnetARRAY[16] of BACnetValueSource | O11,13 | no | no | No default: the read fails. |
| Last_Command_Time | BACnetTimeStamp | O11,13 | no | no | No default: the read fails. |
| Command_Time_Array | BACnetARRAY[16] of BACnetTimeStamp | O13 | no | no | No default: the read fails. |
| Audit_Level | BACnetAuditLevel | O15 | not in profile | not in profile | No default: the read fails. |
| Auditable_Operations | BACnetAuditOperationFlags | O15 | not in profile | not in profile | No default: the read fails. |
| Audit_Priority_Filter | BACnetOptionalPriorityFilter | O15 | not in profile | not in profile | No default: the read fails. |
| Tags | BACnetARRAY[N] of BACnetNameValue | O | no | no | No default: the read fails. |
| Profile_Location | CharacterString | O | no | no | "" |
| Profile_Name | CharacterString | O | no | no | "" |