Rockwell Automation Publication 1756-UM010C-EN-P - June 2021
15
Chapter
2
Configurable Flowmeter Operation in
the ControlLogix System
What This Chapter Contains
This chapter describes how the module works within the ControlLogix®
system.
In traditional industrial applications, controllers poll flowmeter modules to
obtain their status. Controllers also send commands to the flowmeter
modules. Retrieving flowmeter status and sending commands occurs during
the normal I/O program scan.
ControlLogix CFM modules do not follow the traditional operational manner.
Instead, they use the
for more
information) to produce data without having been polled by a controller first.
Configurable flowmeter modules follow these basic operational steps, as
shown in
.
1. The Logix controller establishes a connection to the module and
downloads configuration via ladder logic and message instructions.
2. Flowmeters transmit input signals to the module.
3. The module calculates volume from accumulated pulse counts as
engineering units.
4. Rather than being scanned by an owner-controller, the module
periodically multicasts its status to the controller. (see
.) The module also multicasts its status to
controllers connected by a listen-only connection (
).
