Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 30)

Publication 1785-UM012D-EN-P - July 2005
1-12 Understanding Your Programmable Controller
A controller transfers I/O data and status data using:
Using a Controller Channel
as a Remote I/O Adapter Configure a controller channel for adapter mode when you need predictable,
real-time exchange of data between a distributed control adapter-mode
controller channel and a supervisory controller. The remote I/O adapter
channel exchanges data with a supervisory controller.
•
discrete
transfers data transfers of 8 words per rack
occur automatically on the remote I/O network
•
block-transfers special data transfers that require ladder logic
instructions to achieve the transfer
allow a transfer of a maximum of 64 words of data
also used to communicate information between a
scanner channel and an adapter-mode controller
channel
Remote I/O
Link Cable:
Belden 9463
PLC-5/40
1771-ASB
PLC-5/20
In this example, a PLC-5/40 controller channel is
the supervisory (scanner-mode) controller of the
1771-ASB module and the PLC-5/20 controller.
Connect the controllers via the remote I/O link.
The adapter-mode PLC-5 controller can monitor
and control its controller-resident local I/O while
communicating with the supervisory controller via
a remote I/O link.
You can monitor status between the
supervisory controller and the adapter-mode
PLC-5 controller channel at a consistent rate
(i.e., the transmission rate of the remote I/O link
is unaffected by programming terminals and
other non-control-related communications).