ClientReadProperties_NameValueUnitDescription

ClientReadProperties_NameValueUnitDescription (FB)

FUNCTION_BLOCK ClientReadProperties_NameValueUnitDescription

Short description

Updating four specified properties of a BACNET object (read access) Typical application: Querying the properties of an ANALOG-INPUT object via BACNET

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
xEn	BOOL		TRUE	Enable / disable communication ( TRUE = enabled )
itfServer	BACnet.IBACnetServer			Interface variable for referencing the server
xUpdateActual	BOOL		FALSE	Update of actual values ( on each rising edge )
xResError	BOOL		FALSE	Reset of the error outputs ‘eErrorCodeCom’ and ‘eRepyErrorCode.XXX’ (on each rising edge)

Outputs

Name	Data type	Value range	Initial value	Function
dwDeviceID_Fb	DWORD		0	Number of the BACnet target device (range: 0 - 4194302) - feedback
eObjectType_Fb	BACnet.CmpBACnet.IEC_BACnet_Object_Type			Type of the object - feedback
dwObjectInstance_Fb	DWORD		0	Number of the object (range: 0 - 4194303) - feedback
sObjectName	STRING			Name of the object
sValueOutput	STRING		‘’	Display of the output for the current value (PRESENT_VALUE) of the object
xValidValue	BOOL		FALSE	Status of the validity of the current value (PRESENT_VALUE) (TRUE = current value valid)
rValue	REAL			Current value of the property in REAL format (floating point according to IEEE754 - 32 bit)
xValue	REAL			Current value of the property in BOOL format
sValue	STRING			Current value of the property in STRING format (character string)
diValue	DINT			Current value of the property in DINT format (signed integer)
udiValue	UDINT			Current value of the property in UDINT format (unsigned integer)
byValue	BYTE			Current value of the property in BYTE format (integer 0 - 255)
lrValue	LREAL			Current value of the property in LREAL format (floating point according to IEEE754 - 64 bit)
sObjectUnit	STRING			Unit for the current value (PRESENT_VALUE) of the object
sObjectDescription	STRING			Description of the object
xRegToServer	BOOL		FALSE	Status of registration at the BACnet server (TRUE = successful registration)
xConfigObject	BOOL		FALSE	Status of the object's configuration (TRUE = successful configuration)
eState	BACnet.CmpBACnet.IEC_BACNET_STATUS			Status of communication
eErrorCodeCom	BACnet.CmpBACnet.IEC_BACNET_STATUS			Most recent communication error
eErrorCodeDevice	BACnet.CmpBACnet.IEC_BACNET_ERROR_CODE			Most recent device error transmitted by the BACnet target device (BACnet server)
eReplyErrorCode	TYPE_OF_REPLY_ERROR_CODE			Most recent communication error in the reply to one's own request
xAlarm	BOOL		FALSE	General fault ( TRUE = fault )
xAlarmCom	BOOL		FALSE	General fault - communication ( TRUE = fault )
xBusy	BOOL			Communication indicator ( TRUE = communication )

Setpoints / parameters

Name	Data type	Value range	Initial value	Function
tTimeUpdateActual	TIME		T#3s	Update interval for operations influenced by the input 'xUpdateActual' ( 0 = no automatic update, > 0 cyclical update )
dwDeviceID	DWORD			Number of the BACnet target device (range: 0 - 4194302)
eObjectType	BACnet.CmpBACnet.IEC_BACnet_Object_Type		BACnet.CmpBACnet.IEC_BACnet_Object_Type.OBJ_ANALOG_INPUT	Type of the object
dwObjectInstance	DWORD			Number of the object (range: 0 - 4194303)

Function description

General

This function block transfers four predefined properties of an object via BACNET communication (read access). The properties OBJECT_NAME, PRESENT_VALUE, UNITS and DESCRIPTION (as far as possible) are read. The selection of the object to be read is made via the parameters dwDeviceID, eObjectType and dwObjectInstance. The validity of the current value (PRESENT_VALUE) after a transfer is signaled at the output 'xValidValue'. The output with the current value (PRESENT_VALUE) is presented at the output 'sValueOutput' after a successful transfer. \

Enable / disable communication

Enable/disable of communication is done via the input 'xEn' (Default = TRUE = enabled). On each rising edge at the input 'xEn', a transfer of the current value with the current settings is triggered. In the disabled state the outputs assume predefined states, and an unregister from the server takes place at the same time. \

Triggering a transfer

The transfer of the property's current value can be triggered as follows (precondition: xRegToServer = TRUE) \

• every rising edge at the input 'xEn'

• every rising edge at the input 'xUpdateActual'

• periodically at the interval 'tTimeUpdateAvtual' (Default: T#3s)

• once after each download

• once after each change of configuration \

Configuration of the BACNET object

The BACNET object is uniquely defined by the following parameters: \

• Device address 'dwDeviceID'

• Object address 'dwObjectInstance'

• Object type 'eObjectType'\

Feedback of the current parameters

At the outputs with the index '_Fb' the current settings of the BACNET parameters are available for display purposes.\

Output 'sValueOutput'

At this output the name of the output variable containing the valid current value (PRESENT_VALUE) is available after a successful transfer.\

Output 'xValidValue'

At this output the validity of the current value (PRESENT_VALUE) is available after a successful transfer.\

Outputs for the current value of the object

Depending on the validity of the current value (xValidValue = TRUE) and the name of the output variable (sValueOutput) the current value is available at the corresponding output.\

Output 'xRegToServer'

This output permanently provides the status of the internal connection to the BACNET server. Successful connection establishment to the server is a prerequisite for transferring the setpoint.\

Output 'xConfigObject'

This output permanently provides the status of the successful configuration of the BACNET object.\

Display of faults

Fault indication is displayed at the collective output 'xAlarm' (= TRUE). It includes the current states of communication errors (xAlarmCom) and device errors (xAlarmDevice). Communication faults are displayed at the output xAlarmCom with a time delay: gc_Parameters.gc_tOnDelayxAlarmCom (Default = 60s). Device faults are displayed without delay at the output xAlarmDevice. In case of a communication error, an explanatory text for the cause is available at the output 'eErrorCodeCom'. It always shows the cause of the last communication error. In case of a device error, an explanatory text for the cause is available at the output 'eErrorCodeDevice'. It always shows and updates the cause of the last communication error. In case of an error in the reply telegram, an explanatory text for the cause is available at the output 'eReplyErrorCode'.\

Output 'xBusy'

This output signals the active transfer of the current value (= TRUE).\

CODESYS

InOut:

Scope	Name	Type	Initial	Comment
Input	xEn	BOOL	TRUE	Enable / disable communication ( TRUE = enabled )
Input	itfServer	BACnet.IBACnetServer		Interface variable for referencing the server
Input	xUpdateActual	BOOL	FALSE	Update of actual values (on every rising edge )
Input	xResError	BOOL	FALSE	Reset of the output 'eError' (on each rising edge)
Output	dwDeviceID_Fb	DWORD		Number of the BACnet target device (range: 0 - 4194302) - feedback
Output	eObjectType_Fb	BACnet.CmpBACnet.IEC_BACnet_Object_Type		Type of the object - feedback
Output	dwObjectInstance_Fb	DWORD		Number of the object (range: 0 - 4194303) - feedback
Output	sObjectName	STRING		Name of the object
Output	sValueOutput	STRING	‘’	Display of the output for the current value of the property
Output	xValidValue	BOOL	FALSE	Status of the validity of the current value of a property (FALSE = current value invalid)
Output	rValue	REAL		Current value of the property in REAL format (floating point according to IEEE754 - 32 bit)
Output	xValue	BOOL		Current value of the property in BOOL format
Output	sValue	STRING(255)		Current value of the property in STRING format (character string)
Output	diValue	DINT		Current value of the property in DINT format (signed integer)
Output	udiValue	UDINT		Current value of the property in UDINT format (unsigned integer)
Output	byValue	BYTE		Current value of the property in BYTE format (integer 0 - 255)
Output	lrValue	LREAL		Current value of the property in LREAL format (floating point according to IEEE754 - 64 bit)
Output	sObjectUnit	STRING		Unit of the measured value
Output	sObjectDescription	STRING		Description of the object
Output	xRegToServer	BOOL		Status of registration at the BACnet server (TRUE = successful registration)
Output	xConfigObject	BOOL		Status of the object's configuration (TRUE = successful configuration)
Output	eCBMState	BACnet.CmpBACnet.IEC_BACNET_STATUS		CBM - communication status (updates: states DONE, ERROR and ABORT)
Output	eComState	ClientReadProperty_ComStates		Communication status (updates: states No_Execution, Target_Device_Searching, Request_Sending, Reply_Waiting, Finishing)
Output	eErrorCodeCom	BACnet.CmpBACnet.IEC_BACNET_STATUS		Most recent communication error
Output	eErrorCodeDevice	BACnet.CmpBACnet.IEC_BACNET_ERROR_CODE		Most recent device error transmitted by the BACnet target device (BACnet server)
Output	eReplyErrorCode	TYPE_OF_REPLY_ERROR_CODE		Most recent communication error in the reply to one's own request
Output	xAlarm	BOOL		General fault ( TRUE = fault )
Output	xAlarmCom	BOOL		General fault - communication ( TRUE = fault )
Output	xBusy	BOOL		Communication indicator ( TRUE = communication )
Input Const	dwObjectInstance	DWORD		Number of the object (range: 0 - 4194303)
Input Const	eObjectType	BACnet.CmpBACnet.IEC_BACnet_Object_Type	BACnet.CmpBACnet.IEC_BACnet_Object_Type.OBJ_ANALOG_INPUT	Type of the object
Input Const	dwDeviceID	DWORD		Number of the BACnet target device (range: 0 - 4194302)
Input Const	tTimeUpdateActual	TIME	TIME#3s0ms	Update interval for operations influenced by the input 'xUpdateActual'