Rockwell Automation 1336T PLC Comm. Adapter, Series B, FRN 2.xx-3.xx - Manual (Page 45)

Chapter
3
Publication 1336 FORCE–5.13 –– September, 1998
Using Remote I/O
Communications
This chapter provides information that can help you understand and
use the remote I/O (RIO) communications. This chapter covers the
following topics:
•
understanding RIO communications
•
transferring data using discrete data transfer
•
transferring data using block transfer
•
using RIO redundant mode
•
using RIO scanner mode
When you configure the PLC Communications Adapter Board for
RIO communications, the drive looks like a remote I/O chassis to a
PLC. This allows you to use either discrete message transfer or
block transfer to communicate with the PLC.
With discrete message transfer, the PLC controller’s I/O image table
is used to transfer the data that the drive needs to have continuously
updated.
With block transfer, data is sent between the drive and PLC
controller when requested. Block transfer is the transfer of data, in
blocks of data up to 64 words. For additional information about
using block transfer routines, refer to your PLC user manual.
You can configure channel A, channel B, or both channels for
Allen–Bradley RIO communications. The communications method
that you choose (either RIO or DH+) determines which parameters
for the PLC Communications Adapter Board are defined.
Chapter Objectives
Understanding RIO
Communications