Fifof (Fifo Format) - IDEC MICROSmart FC6A Series Ladder Programming Manual

23: F D
ILE
Introduction
This chapter describes the file data processing instructions that handle the FIFO (first-in first-out) data structure. FIFOF (FIFO
Format) instructions initialize the FIFO data files storing the data. FIEX (First-In Execute) instructions store new data to the FIFO
data files, and FOEX (First-Out Execute) instructions retrieve the stored data from the FIFO data files. The first data to be stored to
the FIFO data files by FIEX instructions will be the first data to be retrieved by FOEX instructions.
NDSRC (N Data Search) instructions search a designated value through a specified range.

FIFOF (FIFO Format)

FIFOF(W)
*
Valid Devices
Device
N (File Number)
S1 (Source 1)
S2 (Source 2)
D1 (Destination 1)
D2 (Destination 2)
For valid device address ranges, see "Device Addresses" on page 2-1.
Special internal relays cannot be designated as D2.
Since the FIFOF instruction is executed in each scan while input is on, a pulse input from a SOTU or SOTD instruction should be used.
Valid Data Types
W (word) X
I (integer) —
D (double word) —
L (long) —
F (float) —
P
ATA ROCESSING
S1 S2 D1
*** *** ***** *****
Function
File Number
Quantity of data registers per record
Quantity of records
First data register to store FIFO data file
FIFO status output
When an M (internal relay) is assigned as the D2, three internal relays starting with the device assigned by D2
are used.
When a D (data register) is assigned as the D1, S1×S2+2 data registers starting with the device assigned by D1
are used.
FC6A S MICROS
ERIES
I
NSTRUCTIONS
When input is on, FIFOF instruction initializes an FIFO data file. Each data
D2 file has unique number 0 through 9. A maximum of 10 data files can be used
in a user program.
I Q
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L P
MART ADDER ROGRAMMING
M R T C D P
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— — — — X —
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M FC9Y-B1726
ANUAL
Constant Repeat
0-9 —
1-255 —
2-255 —
— —
— —
23-1