Plc-5 programming – Rockwell Automation 1794-IF4I, -OF4I, IF2XOF2I, -IF4IXT, -IF4ICFXT, -OF4IXT, IF2XOF2IXT FLEX I/O Isolated Analog Modules User Manual

Page 35

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Publication 1794-6.5.8 - January 2010

Module Programming 35

Figure 1.3

PLC-3 Family Sample Program Structure for a 1794-IF2XOF2I Module

PLC-5 Programming

The PLC-5 program is very similar to the PLC-3 program with the
following exceptions:

block transfer enable bits are used instead of done bits as the
conditions on each rung.

separate block transfer control files are used for the block
transfer instructions.

EN

BTR

BLOCK XFER READ
RACK:
GROUP:
MODULE:
CONTROL:

02
02

0

#B9:0

DATA FILE:
LENGTH:

#B10:0

7

EN

BTW

BLOCK XFER WRITE
RACK:
GROUP:
MODULE:

CONTROL:

02
02

0

#B9:0

DN

DATA FILE:
LENGTH:

#B11:0

7

B9:0

05

Block Transfer
Read Done Bit

ER

Enable

Done

Error

12

15

13

Enable

Done

Error

02

05

03

Block Transfer
Write Done Bit

1

3

DN

ER

B9:0

15

Program Action

At power-up in RUN mode, or when the
processor is switched from PROG to RUN,
the user program enables a block transfer
read.

Thereafter, the program continuously
performs read block transfers and write
block transfers.

Note: You must create the data file
for the block transfers before you
enter the block transfer instructions.

2

14

B10:5

15

13

Power-up Bit

FP Bit

CF Bit

B11:6

15

IC Bit

B10:5

B10:5

Then it initiates a block transfer write to
configure the module and send data values

This rung toggles the Initate Configuration
bit from 0 to 1 to 0

L

14

B11:6

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