BC21PopBuf
B = Buffer
C = Calculation functions
The BC21PopBuf functionm extracts a value from a FIFO memory. FIFO memory is implemented using a variable of array type.
IMPLEMENTATION
BC21PopBuf (array, Element, ErrorCode, head, tail)
Parameters:
| IN/OUT | VARIABLE TYPE | EXAMPLE NAME | DIM | |
|---|---|---|---|---|
| IN | ARRGBL / ARRSYS | Buffer | B/W/L/S | Array containing the Buffer |
| OUT | GLOBAL | Element | L/S / W / B | Variable on which you place the value retrieved from the buffer |
| OUT | GLOBAL | ErrorCode | F | Variable containing the error possibly occurred during insertion of the value |
| IN | GLOBAL / SYSTEM | head | L | Internal index |
| IN | GLOBAL / SYSTEM | tail | L | Internal index |
Error
After calling the function if there are any errors the error (ErrorCode) variable takes the following values:
0 - No error, extract data
1 - The FIFO memory is empty
Example
Extracts a data by the buffer queue and places it in the variable “glDato” at every front of the “gfEstrai” variable
MAIN:
IF gfExtract
gfExtract = 0
BC21PopBuf (Buffer, Element, ErrorCode, gl001, gl002)
IF NOT ErrorCode
glDato = Element
ENDIF
ENDIF
Note
-
The use of this function is linked to the BC21InitBuf function that initializes the buffer and that must be called at least once before the BC20PushBuf function.
-
Complementary to this function is the BC21PushBuf function who places a data in the FIFO memory.