Watlow PM PLUS™ 6
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Chapter 9: Applications
Example 1: Single Loop Control
Requirements: One input is required and at least one output adjusts the controlled part of the process.
Overview: Controls one process value to a user entered Set Point based on an control algorithm.
Control loop 1 will control Analog Input 1 to Set Point 1.
Example 2: Sensor Backup
Requirements: Two analog inputs and the enhanced software option are required and at least one output adjusts
the controlled part of the process.
Overview: The Sensor Backup feature controls a process based on a primary sensor on Analog Input 1. If this
sensor fails, then the process is controlled based on the secondary sensor on Analog Input 2.
When function is set for Sensor Backup, the PV Function output equals Source A if sensor of Analog Input 1
reading is valid or Source B if sensor reading is invalid. Control loop 1 will control the valid Analog Input sensor
to Set Point 1.
Sensor Backup
Set
Poin
t 1
Function
Filter
Source A
Source A
Source B
Heat Power
Cool Power
0 to 100%
0 to 100%
Output
Heat
Cool
Output
n
Output
n
Analog Input 1
Analog Input 2
Control Loop 1
PV Function
Control Loop 1
Single Loop Control
Set P
oint
1
Heat
Algorithm
Cool
Algorithm
Analog Input 1
Source A
Heat Power
Cool Power
Heat
Cool
0 to 100%
0 to 100%
Output n
Output n
Chapter 9: Applications
