FB_BACnet_Loop_DRV_EX

FB_BACnet_Loop_DRV_EX 1:

Application

The function block FB_BACnet_Loop_DRV_EX can be used for reading access to a BACnet object of type Loop. In contrast to the standard or _EX version of the function block, the control algorithm is implemented within the BACnet stack (see also FB_BACnet_Loop_EX). The Loop object is therefore in control mode, even without an executable PLC program.

VAR_OUPUT

bReady                    : BOOL;
fSetPoint                 : REAL;
fControlledValue          : REAL;
fPresentValue             : REAL;
fPropBand                 : REAL;
bOverridden               : BOOL;
bOutOfService             : BOOL;
bFault                    : BOOL;
bInAlarm                  : BOOL;
bOpenLoop                 : BOOL;
bCommFailure              : BOOL;
bOtherFault               : BOOL;
eEventState               : E_BACNETEVENTSTATE;
bAckedTrans_ToOffNormal   : BOOL;
bAckedTrans_ToFault       : BOOL;
bAckedTrans_ToNormal      : BOOL;
tObjectID                 : T_BACnet_ObjectIdentifier:=16#FFFFFFFF;
bError                    : BOOL;
nErrorId                  : UINT;

bReady: Notification of general readiness. If this output is set, the other status outputs are valid (PresentValue, Overridden ...). If the output is FALSE, the corresponding function block FB_BACnet_Device does not report "Operational", or the block instance was not linked correctly in the TwinCAT System Manager.

fSetPoint: Feedback of the controller specification (W, set value).

fControlledValue: Feedback of the current process parameter (X, actual value).

fPresentValue: Feedback of the current control output (Y, control value). Attention: Present_Value and Controller_Variable_Value can easily lead to confusion (see also BACnet specification DIN EN ISO 16484-5 for BACnet object Loop and properties Present_Value, Controlled_Variable_Value and Controlled_Variable_Reference).

fPropBand: Feedback of the current control output in percent (-100%...+100%) in relation to the minimum and maximum control output (properties Minimum_Output and Maximum_Output).

bOverridden, bOutOfService, bFault, bInAlarm: See BACnet specification DIN EN ISO 16484-5 for BACnet object Loop and property Status_Flags.

bOpenLoop, bCommFailure, bOtherFault: See BACnet specification DIN EN ISO 16484-5 for BACnet object Loop and property Reliability.

eEventState: See BACnet specification DIN EN ISO 16484-5 for BACnet object Loop and property Event_State.

bAckedTrans_ToOffNormal, bAckedTrans_ToFault, bAckedTrans_ToNormal: Flags of property Acked_Transitions (see BACnet specification DIN EN ISO 16484-5 for BACnet object Loop and property Acked_Transitions).

tObjectID: Object ID of the BACnet object (object type and object instance).

bError: An error is pending.

nErrorId: see global constants BACnet_Globals.

VAR_IN_OUT

Device               : FB_BACnet_Device;

Device: Specification of the instance of the local corresponding BACnet server block. For each BACnet adapter one BACnet server is possible. See FB_BACnet_Adapter and FB_BACnet_Device for further information.

See also