FB_BACnetAV1201

Functional description

This function block generates a BACnet analog value object and provides write and read variables for the object within the PLC.
This function block is the "smallest" version in terms of functionality.
Alternatively the following versions are available:

• FB_BACnetAV1202
• FB_BACnetAV1203

The parameters, which can be written from the PLC, can also be written from the BACnet side; the last change is always the valid one. These parameters are transferred from the PLC via ADS and into the PLC via a cyclic interface. On the PLC side, all parameters have an additional Enable input: when the respective Enable input is set for the first time (rising edge), the value at the parameter input is transferred in any case; subsequently, if Enable is set, it is only transferred if it changes, in order to reduce the ADS traffic. If the Enable input is not set, no transfer takes place.

VAR_INPUT

bEnPrioA  : BOOL;
rValPrioA : REAL;
usiPrioA  : USINT;

bEnPrioA: enable for writing

rValPrioA: value that is written to priority usiPrioA in the priority array.

usiPrioA: selection of the priority (1..16) to be written

VAR_OUTPUT

rPrVal    : REAL;
stStaFlg  : ST_BACnet_StatusFlags;
dwObjId   : DWORD;
bErr      : BOOL;
udiErrId  : UDINT;
udiErrArg : UDINT;

rPrVal: current value of the analog value object - read directly from the BACnet

stStaFlg: output structure of the BACnet status

dwObjId: BACnet object ID of the analog value object

bErr: indicates a general error in the function block. The cause can be in BACnet, in the ADS data exchange, or due to incorrect parameterization.

udiErrId / udiErrArg: contains the error number and the error argument. See error codes.

VAR_IN_OUT

stComnMsg : ST_BA_ComnMsg;
fbDvc     : FB_BACnet_Device;

stComnMsg: reference to the connection structure for the collective message function block FB_BA_ComMsg.

fbDvc: reference to the function block of the BACnet device object

Requirements