# SRV\_AV\_SMALL
## `SRV_AV_SMALL` (FB)
FUNCTION\_BLOCK SRV\_AV\_SMALL
Influence on the current state of the property 'PresentValue' (output)
Priority Condition Function Notes
Highest property 'OutOfService' = TRUE 'PresentValue' can be written directly Forced override of the output 'PresentValue'
Middle state of at least one priority The state of the highest priority (1 = highest, prioritization of requests for the state of PresentValue: of the array <> NULL 16 = lowest) of the array <> NULL determines the value of 'PresentValue'
Lowest states of all priorities 1 - 16 of the array On transition into this priority the value of the determination of the state of 'PresentValue', if there are no valid entries in the array := NULL the property 'RelinquishDefault' is written once to the output 'PresentValue'.
Notes:
The state of a priority of the array can take the following states: NULL (= inactive), FALSE (OFF), TRUE (ON) The most recent access defines the state of PresentValue. ('Last wins') Each new state of 'PresentValue' is transmitted only once when the state changes, there is no continuous transmission (= pulse function).
Priority 6 (only for binary values)
The state of priority 6 must not be used (= written), as it is used for pulse generation on state change of the property 'PresentValue'. Each rising edge on 'PresentValue' generates a pulse (state: TRUE) of length 'MinimumOnTime' ('MinimumOnTime' > 0 s) of priority 6. Each falling edge on 'PresentValue' generates a pulse (state: FALSE) of length 'MinimumOffTime' ('MinimumOffTime' > 0 s) of priority 6.
Notification Class
Conditions:
1. The property 'RecipientList' must be provided with the attribute 'WRITEABLE'.
2. The instance number must be identical to the Notification Class
3. The priorities (0 - 2) should contain values greater than 0 (e.g. all = 1)
Persistence
Conditions:
1. The desired property (e.g. 'Description') must be provided with the attribute 'PERSIST'.
2. Persistence remains until the value of the property changes (xEnValueChange = TRUE) and/or a rising edge is detected at the input 'xInit'.
Unsolicited COV (= unsolicited transmission of state changes to all BACnet participants (broadcast))
Conditions:
1. The property 'SupportUnsolicitedCOV' must be set to 'TRUE' in the BACnet\_Server (central for all BACnet objects)
Status bit 'Fault'
Conditions for the 'TRUE' state
1. The current value of 'rPresentValue' falls below the lower limit 'rFaultLowLimit\_IN' and/or (stOutputs.Reliability = 'UnderRange') (event status from 'NORMAL' to 'FAULT')
2. The current value of 'rPresentValue' exceeds the upper limit 'rFaultHighLimit\_IN'. (stOutputs.Reliability = 'OverRange') (event status from 'NORMAL' to 'FAULT')
Conditions for the 'FALSE' state
In all other cases. (event status from 'FAULT' to 'NORMAL')
Absolute limits of 'rPresentValue'
The output 'rResentValue' accepts values between the two absolute limits (each inclusive) regardless of the input at 'rPresentValue\_IN'.
1. Absolute lower limit for 'rPresentValue': parameter 'rMinPresValue\_IN'
2. Absolute upper limit for 'rPresentValue': parameter 'rMaxPresValue\_IN'
Status bit 'InAlarm'
Conditions for the 'TRUE' state
1. The current value of 'rPresentValue' falls below the lower limit 'rMinPresValue\_IN' and/or (stOutputs.Reliability = 'NoFaultDetected') (event status from 'NORMAL' to 'INALARM')
2. The current value of 'rPresentValue' exceeds the upper limit 'rMaxPresValue\_IN'. (stOutputs.Reliability = 'NoFaultDetected') (event status from 'NORMAL' to 'INALARM')
In addition, the parameter 'rDeadband\_IN' must be considered as follows:
Example: 'rMaxPresValue\_IN' = 98.0, 'rDeadband\_IN' = 1.0 The alarm state is active at 'rPresentValue' > 'rMaxPresValue\_IN'. The alarm state is no longer active at 'rPresentValue' < ('rMaxPresValue\_IN' - 'rDeadband\_IN').
Example: 'rMinPresValue\_IN' = 2.0, 'rDeadband\_IN' = 1.0 The alarm state is active at 'rPresentValue' < 'rMinPresValue\_IN'. The alarm state is no longer active at 'rPresentValue' > ('rMinPresValue\_IN' + 'rDeadband\_IN').
Conditions for the 'FALSE' state
In all other cases. (stOutputs.Reliability = 'NoFaultDetected') (event status from 'INALARM' to 'NORMAL')
Monitoring of the lower and upper limit can be enabled/disabled by respective option switches ('xLowLimitEnable\_IN', 'xHighLimitEnable\_IN').
To transmit an alarm/event to a Notification Class (NC), the option switches 'xEventDetectionEnable\_IN', 'xEventEnableOffNormal\_IM' and 'xEventEnableNormal\_IM' must be activated.
InOut:
| Scope | Name | Type | Initial | Comment |
| ----------- | ------------------------------------- | ----------------------------------------------------- | -------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Input | `itfMasterConnector` | IMasterForServerObjectsPOU | | Input for the interface of the FB ‘MasterForServerObjectsPOU’ |
| Input | `xInit` | `BOOL` | FALSE | Reassignment of all properties (write values/states and update outputs) (on every rising edge) |
| Input | `rPresentValue_IN` | `REAL` | 0.0 | Setting the value of the output 'rPresentValue' with the
priority 'diPriority\_IN'
|
| Input | `udiObjectInstance` | `UDINT` | 1 | Object instance of the server object to be created |
| Input | `sObjectNamePrefix` | `STRING(254)` | ‘’ | Optional prefix for forming the object name — CONCAT(sObjectNamePrefix,sObjectNameText) |
| Input | `sDescriptionPrefix` | `STRING(254)` | ‘’ | Optional prefix for forming the description — CONCAT(sDescriptionPrefix,sDescriptionText) |
| Output | `eObjectTypeFb` | `BACnet.CmpBACnet.IEC_BACNET_OBJECT_TYPE` | | Type of the object - feedback |
| Output | `udiObjectInstanceFb` | `UDINT` | | Object instance of the server object to be created — feedback |
| Output | `rPresentValue` | `REAL` | | Value of 'PresentValue' (Relinquish-default: S /
Priority array: S+C / Out-Of-Service: S+C)
|
| Output | `xPresentValueOverride` | `BOOL` | | Status of the override of the output ‘rPresentValue’ ( TRUE
= override active )
|
| Output | `stProperties` | SRV\_AV\_SMALL\_PROPERTY\_OUTPUTS | | Structure with the current states of selected properties |
| Output | `xRegistered` | `BOOL` | FALSE | Indicates successful registration of the server object |
| Input Const | `eSelectPopertiesToCheckChanges` | ServerObjects\_Select\_Properties\_To\_Check\_Changes | ServerObjects\_Select\_Properties\_To\_Check\_Changes.PresentValue\_only | Selection of properties that are continuously checked for changes on the input (index '\_IN') and changed in the server if necessary
1. ServerObjects\_Select\_Properties\_To\_Check\_Changes.No\_property:
No property is checked
2. ServerObjects\_Select\_Properties\_To\_Check\_Changes.PresentValue\_only:
Only the properties 'PresentValue' (input 'rPresentValue\_IN') and 'Reliability' (input 'eReliability\_IN') are checked
3. ServerObjects\_Select\_Properties\_To\_Check\_Changes.All\_properties
All properties (inputs with the index '\_IN') are checked
|
| Input Const | `eTriggeringUpdateActual` | ServerObjects\_TriggeringUpdateActual | ServerObjects\_TriggeringUpdateActual.CENTRAL\_TRIGGERING | Definition of the trigger for cyclical updating of the outputs
NO\_TRIGGERING: no cyclical update
LOCAL\_TRIGGERING: cyclical update (time duration: tTimeUpdateActual)
CENTRAL\_TRIGGERING: cyclical update (time duration dependent on the number of server objects)
|
| Input Const | `tTimeUpdateActual` | `TIME` | TIME#3s0ms | Update interval for updating the outputs |
| Input Const | `rRelinquishDefault_IN` | `REAL` | 0.0 | Specification of the value of the output ‘rPresentValue’ at the
lowest priority if the priority array is not
populated
|
| Input Const | `diPriority_IN` | `DINT` | 16 | Priority for the input ‘rPresentValue\_IN’ ( 0 - 16, 0 =
none, 1 = highest, 16 = lowest )
|
| Input Const | `eAccessRightEventDetectionEnable_IN` | `BACnet.CmpBACnet.IEC_BACNET_ACCESS` | BACnet.CmpBACnet.IEC\_BACNET\_ACCESS.BACNET\_ACCESS\_HIDDEN | Definition of the access right for the property 'Event Detection Enable' by a client |
| Input Const | `eAccessRightEventEnable_IN` | `BACnet.CmpBACnet.IEC_BACNET_ACCESS` | BACnet.CmpBACnet.IEC\_BACNET\_ACCESS.BACNET\_ACCESS\_HIDDEN | Definition of the access right for the property 'Event Enable' by a client |
| Input Const | `eAccessRightNotifyType_IN` | `BACnet.CmpBACnet.IEC_BACNET_ACCESS` | BACnet.CmpBACnet.IEC\_BACNET\_ACCESS.BACNET\_ACCESS\_HIDDEN | Definition of the access right for the Notification Type by a client |
| Input Const | `eAccessRightTimeDelay_IN` | `BACnet.CmpBACnet.IEC_BACNET_ACCESS` | BACnet.CmpBACnet.IEC\_BACNET\_ACCESS.BACNET\_ACCESS\_HIDDEN | Definition of the access right for the time delay by a client |
| Input Const | `eAccessRightNotificationClass_IN` | `BACnet.CmpBACnet.IEC_BACNET_ACCESS` | BACnet.CmpBACnet.IEC\_BACNET\_ACCESS.BACNET\_ACCESS\_HIDDEN | Definition of the access right for the Notification Class by a client |
| Input Const | `rFaultHighLimit_IN` | `REAL` | 100.0 | Definition of the upper limit of the value of 'rPresentValue' before
activation of the status bit 'Fault'
|
| Input Const | `rFaultLowLimit_IN` | `REAL` | 0.0 | Definition of the lower limit of the value of 'rPresentValue' before
activation of the status bit 'Fault'
|
| Input Const | `xHighLimitEnable_IN` | `BOOL` | FALSE | Enable/disable of the limit 'rHighLimit\_IN' (TRUE =
enable)
|
| Input Const | `xLowLimitEnable_IN` | `BOOL` | FALSE | Enable/disable of the limit 'rLowLimit\_IN' (TRUE =
enable)
|
| Input Const | `rDeadband_IN` | `REAL` | 1.0 | Definition of the value of the property 'rDeadband' |
| Input Const | `rHighLimit_IN` | `REAL` | 99.0 | Definition of the value of the property 'rHighLimit' |
| Input Const | `rLowLimit_IN` | `REAL` | 1.0 | Definition of the value of the property 'rLowLimit' |
| Input Const | `eReliability_IN` | `BACnet.CmpBACnet.IEC_BACNET_RELIABILITY` | BACnet.CmpBACnet.IEC\_BACNET\_RELIABILITY.RELIABILITY\_NO\_FAULT\_DETECTED | Definition of the current state of the property ‘Reliability’ |
| Input Const | `rPresentValueDeviation` | `REAL` | 0.5 | Definition of the deviation (symmetric, plus/minus) of the
value at the input 'rPresentValue\_IN' from the previous value,
|
| Input Const | `xOutOfService_IN` | `BOOL` | FALSE | Forced override for the output 'rPresentValue' with the
highest priority ('xOutOfService' = TRUE) (Only for
Value-Objects)
|
| Input Const | `eUnits_IN` | `BACnet.CmpBACnet.IEC_BACNET_ENGINEERING_UNITS` | BACnet.CmpBACnet.IEC\_BACNET\_ENGINEERING\_UNITS.UNIT\_DEGREES\_C | Definition of the value of the property 'eUnits' |
| Input Const | `rCOVIncrement_IN` | `REAL` | 1.0 | Definition of the value of the property 'rCOVIncrement' |
| Input Const | `rResolution_IN` | `REAL` | 0.1 | Definition of the value of the property 'rResolution' |
| Input Const | `rMaxPresValue_IN` | `REAL` | 100.0 | Definition of the value of the property 'rMaxPresValue' |
| Input Const | `rMinPresValue_IN` | `REAL` | 0.0 | Definition of the value of the property 'rMinPresValue' |
| Input Const | `xEventDetectionEnable_IN` | `BOOL` | FALSE | General enable/disable of event detection (TRUE = enable) |
| Input Const | `xEventNormalEnable_IN` | `BOOL` | FALSE | Enable/disable detection of transitions to the state 'Normal' (TRUE = enable) |
| Input Const | `xEventFaultEnable_IN` | `BOOL` | FALSE | Enable/disable detection of transitions to the state 'Fault' (TRUE = enable) |
| Input Const | `xEventOffNormalEnable_IN` | `BOOL` | FALSE | Enable/disable detection of transitions to the state 'Off-Normal' (TRUE = enable) |
| Input Const | `eNotifyType_IN` | `BACnet.CmpBACnet.IEC_BACNET_NOTIFY_TYPE` | BACnet.CmpBACnet.IEC\_BACNET\_NOTIFY\_TYPE.NOTIFY\_TYPE\_ALARM | Definition of the type of the associated Notification Class |
| Input Const | `udiTimeDelay_IN` | `UDINT` | 0 | Definition of the value of the property ‘udiTimeDelay’ in seconds |
| Input Const | `udiNotificationClass_IN` | `UDINT` | 40 | Definition of the number of the associated Notification Class |
| Input Const | `sDescriptionText` | `STRING(254)` | ‘’ | Text part of the description |
| Input Const | `sObjectNameText` | `STRING(254)` | ‘’ | Text part of the object name of the server object to be created |
| Input Const | `xEn` | `BOOL` | TRUE | Enable / disable communication ( TRUE = enabled ) |