Direct connections – Rockwell Automation 1756-HSC ControlLogix High Speed Counter Module User Manual
Page 56
Rockwell Automation Publication 1756-UM007C-EN-P - November 2011
56 Configure the 1756-HSC Module
A remote chassis, also known as a networked chassis, contains the
1756-HSC module but not the module’s owner-controller. See
for
important information about running RSNetWorx™ software with a remote
chassis.
The illustration shows how the module communicates with its
owner-controller. If connections are severed or compromised, the
1756-HSC module performs as configured, either setting all outputs to reset
(On or Off) or continuous operations.
Module Communication with its Owner-controller
A module’s communication, or multicasting, behavior varies depending upon
whether it operates in the local chassis or in a remote chassis. The following
sections detail the differences in data transfers between these setups.
Direct Connections
A direct connection is a real-time data transfer link between the controller and
the device that occupies the slot that the configuration data references. When
module configuration data is downloaded to an owner-controller, the
controller attempts to establish a direct connection to each of the modules
referenced by the data.
Path No.
Description
1
Controller transfers configuration data and commands to the module.
2
External devices generate input signals that are transmitted to the
module.
3
Module converts signals, stores values, and controls output without being
updated by the controller.
4
Controller stores the counts or frequency values in descriptive and easily
understood tags.
5
Ladder logic program can store and move data before the inputs trigger
new data.
44779
Logix Controller
1756-HSC Module
1
2
3
4
5
Tags
User Program