User`s guide

Release E UMC800 Control Builder User’s Guide 237
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Appendix B - Loop Application Examples
Overview
Introduction
The UMC800 supports up to eight control loops with PID or ON/OFF control action. Control loops may be
configured to operate independently or in cascade.
When Ratio control is applied, a ratio and bias adjustment are provided.
When used with the supplementary loop control blocks, digital inputs may be used to set control mode,
select the setpoint source, change control action, and perform other discrete actions.
A mode indication block provides digital outputs to facilitate integrating loop operation with other
functions in the controller.
When configured for dual output (Heat/Cool), each output may be directed to different output types, for
example: Current, Time Proportioning, etc. Two sets of tuning constants for heating and cooling are also
provided.
This section provides examples of Loop Control Applications.
What’s in this section?
The following examples are covered in this section.
Topic See Page
• PID Block Examples
− Example 1 Simplified PID Configuration
− Example 2 PID Block Configuration – Basic
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• PID Control Algorithms Examples
− Example 1 Duplex Control
− Example 2 Cascade Control
− Example 3 Ratio Control
− Example 4 Assigning Alarm Relays to Loop Alarms
− Example 5 HI or LO Input Selection for PID Control
− Example 6 Transferring PID Loop Manual/Auto Status
− Example 7 External Selection Of Controller Auto/Manual Mode
− Example 8 Remote Switching of Control Action and Tuning Constants
− Example 9 Cascade Control of a Boiler Drum Level - Basic
− Example 10 Cascade Control of a Boiler Drum Level - 3 Element Feedwater
Control
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• 3 Position Step Control for Motor Positioning Example 245