Read Data File: Fread(700) - Omron SYSMAC CJ - REFERENCE MANUAL 01-2008 Reference Manual

File Memory Instructions

3-26-2 READ DATA FILE: FREAD(700)

Purpose
Ladder Symbol
Variations
Applicable Program Areas
Operands
1100
Name
Accessing File Flag A34314
Number of Data to A346 to
Transfer A347
EM File Memory-related Words and Bits
Name
EM File Memory For- A34306
mat Error Flag
EM File Format Starting A344
Bank
Reads the specified data or amount of data from the specified data file in file
memory to the specified data area in the CPU Unit.
FREAD(700)
C
S1
S2
D
Variations Executed Each Cycle for ON Condition
Executed Once for Upward Differentiation
Executed Once for Downward Differentiation Not supported.
Immediate Refreshing Specification
Block program areas
OK OK
C: Control Word
As shown in the following diagram, the first digit indicates whether the source
Address
ON when file data is actually being accessed.
Use this flag as an execution condition to pre-
vent a file memory instruction from being exe-
cuted while another is in progress.
The contents of these words indicate the sta-
tus of data file transfers.
When an FREAD(700) or FWRIT(701) instruc-
tion is executed, the number of words or fields
to be transferred is written to these words. The
value is decremented by 1 as each word or
field is transferred.
A346 contains the rightmost 16 bits and A347
contains the leftmost 16 bits of the 32-bit
binary value.
Address
ON when there is a format error in the starting
bank of EM file memory.
Contains the starting bank number of the EM
Area that has been formatted for use as EM
file memory. Contains FFFF when none of the
EM Area has been formatted.
To convert the EM Area for use as file memory,
the PLC Setup's EM File Memory setting must
be set to 1 and the EM File Memory Starting
Bank (0 to C) must be set. All EM banks from
the starting bank to the last bank will then be
formatted for use as file memory.
C: Control word
S1: Number of words and
First source word
S2: Filename
D: First destination word
Step program areas Subroutines
OK
Section 3-26
Operation
Operation
FREAD(700)
@FREAD(700)
Not supported.
Interrupt tasks
OK