Rockwell Automation 1771ACN/B_1771ACNR/B,D17716.5.123 U.MNL CONTROLNET ADAPTER User Manual

Page 41

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Planning to Use Your ControlNet Adapter Module

4–5

Publication 1771-6.5.123 – May 1996

Example: Nondiscrete Output Module Communications

0 1 2 3 4 5 6 7

PLC-5/40C

0 1 2 3 4 5 6 7

1771-OFE

1771 8 Point In

1771-P4S

Empty

Nondiscrete Output Module

1

2

3

1. The processor opens a connection to the adapter for producing the

data for the nondiscrete module.

2. The processor produces the most recent copy of the designated

data table value you specified in your configuration onto the
network at the Actual Network Packet Time.

3. The adapter consumes the packet from the processor, and initiates

a nondiscrete write transfer to the output module. Only 1
nondiscrete write transfer is active to any module at a time.

Nondiscrete I/O data is stored in integer files that you specify in your
ControlNet configuration screen. Each map entry for a nondiscrete
I/O data transfer defines an offset into the Data Input File (DIF) or
Data Output File (DOF) where data is stored.

Using separate data table files for nondiscrete I/O data transfer
allows the processor to present nondiscrete I/O data in the same
manner as discrete I/O data – continuously transmitted and
asynchronous to the ladder logic program scan.

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