Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 29)

Publication 1785-UM012D-EN-P - July 2005
Understanding Your Programmable Controller 1-11
Using a Controller Channel
as a Remote I/O Scanner Configure a remote I/O channel for scanner mode to read and write I/O
information between a controller and an I/O device remotely located from the
controller.
Remote I/O
Link Cable:
Belden 9463
PLC-5/40
1771-ASB
PLC-5/20
A controller with a channel configured for scanner mode
acts as a supervisory controller for other controllers that
are in adapter mode as well as remote I/O adapter modules.
The scanner-mode PLC-5 controller can:
gather data from node adapter devices in remote I/O racks
process I/O data from 8-, 16-, or 32-point I/O modules
address I/O in 2-, 1-, or 1/2-slot I/O groups
support a complementary I/O configuration
support block-transfer in any I/O chassis
Output Input
PLC-5
Data Table
The scanner-mode PLC-5 controller:
transfers discrete data and block-transfer data
to/from modules in remote I/O racks as well as
to/from controllers in adapter mode.
scans remote I/O buffers asynchronously to the
program scan.
updates the input/output image data table from
the remote I/O buffer(s) synchronously to the
program scan
Controller
-resident
I/O PLC-5 data table
is updated
synchronously to
program scan
(at housekeeping).
Remote I/O buffers
are updated
asynchronously to
the program scan.
Output Input
Remote I/O
Buffer
Remote I/O
Link