ST_FileRBufferHead

Ring buffer file header status. This structure is used by the function block FB_FileRingBuffer. This structure is read when the ring buffer file is opened and saved in the ring buffer file when it is closed. This structure is always updated when data sets are read/written.

TYPE ST_FileRBufferHead :
STRUCT
    status   : DWORD := 0;(* buffer status flags Bit 0 = 1 => Opened, Bit 0 = 0 => Closed, Bit 1 = 1 file corrupted, all other bits are reserved *)
    access   : UDINT := 0;(* access counter, increments every time the buffer is reopened *)
    nID      : UDINT := 0;(* user defined value *)
    cbBuffer : UDINT := 16#100000;(* max. buffer size (1MB) *)
    nCount   : UDINT := 0;(* number of fifo entries *)
    cbSize   : UDINT := 0;(* current (used) file buffer data byte length *)
    ptrFirst : UDINT := 0;(* seek pointer start position of first (oldest) buffer entry *)
    ptrLast  : UDINT := 0;(* seek pointer end position of last (newest) buffer entry *)
    rsrv0    : UDINT := 0;(* reserved *)
    rsrv1    : UDINT := 0;(* reserved *)
    rsrv2    : UDINT := 0;(* reserved *)
    rsrv3    : UDINT := 0;(* reserved *)
END_STRUCT
END_TYPE

Value	Meaning
status	Status flags. Bit 0 = 1 => file is open, bit 0 = 0 => file is closed. Bit 1 = 1 => file is corrupt (was not closed properly, or the maximum buffer size does not match).
acces	Access counter. This counter is incremented whenever the file is opened.
nID	User-defined 32-bit value.
cbBuffer	Maximum ring buffer file size.
nCount	Current number of stored data sets.
cbSize	Current number of stored data bytes.
ptrFirst	File pointer position of the oldest data set.
ptrLast	File pointer position of the latest data set.
rsrv0..rsrv3	Reserved

Requirements

Development environment	Target platform	PLC libraries to be integrated (category group)
TwinCAT v3.1.0	PC or CX (x86, x64, Arm^®)	Tc2_Utilities (System)