ST_BACnet_GlobalAdsBuffer

Data structure of the global PLC ADS buffer. This buffer is used by the following function blocks for buffering the ADS data stream for reading and writing of complex properties:

• FB_BACnet_EventMessageTextsProperty
• FB_BACnet_ExceptionScheduleProperty
• FB_BACnet_LogBufferProperty
• FB_BACnet_ObjectListProperty
• FB_BACnet_RecipientListProperty
• FB_BACnet_WeeklyScheduleProperty

The buffer size is 8 kbyte. Function blocks that use the buffer prevent simultaneous access using the function TestAndSet from the library of the same name. However, this means that multiple read or write access operations with above function blocks are not processed in parallel, but sequentially. The access control is handled internally in the function block.

TYPE ST_BACnet_GlobalAdsBuffer :
STRUCT
  bTestSet : BOOL;
  iLocked  : DINT;
  arrData  : ARRAY[0..8191] OF BYTE;
END_STRUCT
END_TYPE

bTestSet: Lock bit of the function TestAndSet.

iLocked: Current blocked data size in the buffer.

arrData: Data buffer (8192 byte).