Rockwell Automation D17846.2.4 CONTROLNET KT EMULA - Manual (Page 9)

Publication 1784-6.2.4 - September 1997
Chapter
1
Overview of the KTCX Card
Environment
What This Chapter Covers To build a driver that handles all the conditions of your system, you
must be familiar with:
• ControlNet

Network Environment
• Hardware and Software Interface of the KTCX Card
• Data Flow From Application to KTCX Dual-port Interface to
Network
• KTCX Card Requirements and Operating States
ControlNet Network
Environment Read the following sections before building your driver:
• The ControlNet System Overview
• Node Addressing and Node Table
• Control and Configuration of Programmable Controllers
• Off-link Messaging
The ControlNet System Overview
ControlNet networks allow you to combine the benefits of several
networks into one. I/O, PLC interlocking, peer-to-peer messaging,
and programming can all be handled on the same link. The
ControlNet network's 99 nodes, redundant media, high throughput
and determinism, allow your network to handle large distributive
processes, large amounts of remote and analog data, and high-speed
discrete remote and analog data.
The KTCX card connects the host to a ControlNet network environ-
ment. The KTCX card's KT Emulation allows unscheduled messag-
ing and programming to be handled on the ControlNet network.
Unscheduled messages are performed during the unscheduled time in
the network update interval and are non-deterministic. The traffic
load of your scheduled messaging determines how much time is
available for unscheduled messaging. More information on unsched-
uled messages can be found in the ControlNet Network System Over-
view (1786-2.9).
Figure 1.1 outlines the configuration of a typical ControlNet network
environment.