FIFO

FIFO (FB)

FUNCTION_BLOCK FIFO

FIFO is a First-In First-Out memory with x storage locations for INT data. The two outputs xEmpty and xFull indicate when the memory is empty or full. The input xReset clears the entire contents of the memory. The FIFO is written with an INT by setting TRUE on the xWrite input. A read command is executed by setting TRUE on xRead. Reading and writing can be performed simultaneously in one cycle. The block reads or writes in every cycle. The FIFO can be controlled via 3 methods mRead, mWrite, mReset.

InOut:

Scope	Name	Type	Comment
Input	iDataIn	INT	Data to write into the FIFO
Input	xRead	BOOL	Read control
Input	xWrite	BOOL	Write control
Input	xReset	BOOL	Reset control
Input	aiFifoBuffer	POINTER TO INT	FIFO with x slots
Output	iDataOut	INT	Data from the FIFO that were read
Output	xEmpty	BOOL	xEmpty = TRUE means: memory is empty
Output	xFull	BOOL	xFull = TRUE means: memory is full
Output	diDataNumber	DINT	Number of data items in the FIFO