Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules User Manual
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Rockwell Automation Publication 1756-UM058G-EN-P - November 2012
Glossary
minor revision
A module revision that is updated any time there is a change to the module that
does not affect its function or interface.
multicast
Data transmissions that reach a specific group of one or more destinations.
multiple owners
A configuration set-up where multiple owner-controllers use exactly the same
configuration information to simultaneously own an input module.
network update time (NUT)
The smallest repetitive time interval in which the data can be sent on a
ControlNet network. The NUT ranges from 2 ms to 100 ms.
owner-controller
The controller that creates and stores the primary configuration and
communication connection to a module.
program mode
In this mode the following events occur:
•
Controller program is not executing.
•
Inputs are still actively producing data.
•
Outputs are not actively controlled and go to their configured
Program mode.
rack connection
An I/O connection where the 1756-CNB module collects digital I/O words into
a rack image to conserve ControlNet connections and bandwidth.
rack optimization
A communication format in which the 1756-CNB module collects all digital I/
O words in the remote chassis and sends them to controller as a single rack image.
remote connection
An I/O connection where the controller establishes an individual connection
with I/O modules in a remote chassis.
removal and insertion under power
(RIUP)
ControlLogix feature that allows a user to install or remove a module or RTB
while power is applied.
removable terminal block (RTB)
Field wiring connector for I/O modules.
requested packet interval (RPI)
The maximum amount of time between broadcasts of I/O data.
run mode
In this mode, the following events occur:
•
Controller program is executing
•
Inputs are actively producing data
•
Outputs are actively controlled
service
A system feature that is performed on user demand, such as fuse reset or
diagnostic latch reset.
system side
Backplane side of the interface to the I/O module.
tag
A named area of the controller’s memory where data is stored.
timestamping
A ControlLogix process that stamps a change in input data with a relative time
reference of when that change occurred.