Allen-Bradley 1756-CFM, Руководство пользователя

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Rockwell Automation Publication 1756-UM010C-EN-P - June 2021 45
Chapter 3 Configurable Flowmeter Module Features and Operational Modes
Trickle Function for Totalizer Mode
The trickle function is used with the filler function to improve volume
repeatability in a filling application. The trickle function requires two filling
lines and an optional discrete module to activate the trickle valve. Activation of
the valve should be sized for worst case volume at least 100 ms based on typical
program scan = 5 ms and an output module RPI = 25 ms.
For most of the filling process, the full flow state is assigned to one of the
module’s outputs. For more repeatable fills or to prevent overfills, the
pretrigger feature helps make sure that the full flow valve turns off before it
reaches the
Fill Transition or Fill Total Target volume.
When the filling application reaches the user-defined Fill Transition point, the
trickle Totalizer mode changes the application from the full flow line to the
trickle flow line. This slower line allows the application to finish the filling
process without any waste.
For more information on the Fill Transition feature, see page 51 .
The filler function can be used in any of these conditions:
• Starting with the trickle flow
• Filling with the full flow only
• Restarting the timed trickle flow
• Starting the trickle flow prior to the fill transition
• Restarting full flow while in trickle flow
Using the Trickle feature in previously mentioned conditions requires specific
configuration changes.