User Manual Owner manual

Chapter
2
2-1
Planning to Use Your ControlNet
PLC5 Processor
If you want to read about: Go to page:
Understanding ControlNet I/O
21
Understanding ControlNet I/O mapping 27
Using the ControlNet PLC5 processor in a ControlNet I/O system 213
Converting from a remote I/O system to a ControlNet I/O system 215
The ControlNet system is designed to:
provide high-speed, repeatable, deterministic I/O transmission
allow control and message information to co-exist on the same
physical media
make sure that I/O data transfers are not affected by
- programming-terminal message activity
- inter-PLC processor message activity on the network
Scheduled DataTransfer Operations on a ControlNet Network
ControlNet scheduled data transfer on a PLC-5/20C or -5/40C processor:
is continuous
transmits asynchronous to the ladder-logic program scan
occurs at the actual rate displayed on the 6200 Programming Software
ControlNet I/O Mapping (Monitor) screen in the
Act Net Pckt Time
(ms)
—Actual Network Packet Time—field
In scheduled discrete I/O data transfer, for example, between logic
scans—i.e., during “housekeeping”—the following updates occur:
the gathered input image is moved from a private memory buffer to the
processor’s input-image file for use during the next logic scan
the data from the output-image file is put into a private memory buffer
and is sent during the next scheduled communication
Using This Chapter
Understanding
ControlNet I/O