Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers User Manual
Page 100
Publication 1785-UM012D-EN-P - July 2005
7-2 Communicating with a PLC-5 Adapter Channel
Configuring
Communication to a
PLC-5 Adapter Channel
Because a PLC-5 controller adapter channel is more intelligent than a
1771-ASB module, data communication and configuration tasks are handled
differently for adapter channels.
The supervisory controller or scanner channel and the adapter-mode
controller channel automatically transfer discrete data and status between
themselves via the supervisory controller’s remote I/O scan.
Discrete data and block-transfer status bits are transferred between a remote
I/O scanner’s I/O image table and an adapter channel via the adapter
channel’s discrete transfer configuration files, which you define on the adapter
channel configuration screen.
Remote I/O Scan
Program Scan
Housekeeping
Buffer
Remote I/O
I/O Image
Table
Logic
Scan
During each remote I/O scan, the supervisory processor transfers
2, 4, 6, or 8 words*depending on whether the adapter-mode
processor is configured as a 1/4, 1/2, 3/4, or full rack.
The adapter-mode processor transfers 2, 4, 6, or 8 words*depending
on whether it is configured as a 1/4, 1/2, 3/4, or full rack.
Supervisory Processor in Scanner Mode
PLC-5 Processor Channel in Adapter Mode
Discrete Transfer
Configuration Files
Update
I/O image
a
write outputs
b
read inputs
Update
I/O image
a b
a
write
outputs
b
read
inputs
Buffer
Remote I/O
Data Exchange
Discrete
Data and
Status Bit
Exchange
I/O Image
Table
a b
Housekeeping
For the Scanner Channel to Communicate with a PLC-5 Controller Adapter
Channel, Do the Following
For More Information, See
1.Define the communication rate, its address, and rack size (number of words to transfer). page 7-3
2.Define the discrete transfer configuration files, which are the files from which the
adapter controller channel gets the data sent by the supervisory controller and puts data
into for the supervisory controller.
3.If you plan to block-transfer data to the adapter channel, define the block-transfer files
and configure the block-transfers.
4.Connect the remote I/O cable.
your controller installation
instructions