Instruction Manual

Chapter 3: Operating with AnaWin 3 PPC-2000 User’s Guide

110 Watlow Anafaze Doc.# 30002-00 Rev 2.3

Figure 3.10 Relationship between the Master

Channel’s Process Variable and the

Ratio Channel’s Set Point.

Setting up Ratio Control

To set up ratio control:

1. Set up the master channel as you would for a standard

closed-loop application. See Setting up Control Channels

on page 92.

2. Set up the ratio channel as you would for a standard

closed-loop application.

3. Make the following additional settings on the ratio

channel:

a. For Set Point Source select the analog input that should

be used to determine the set point (the PV Source of the

master channel).

b. Set the Set Point Ratio and Set Point Offset to create the

desired relationship between the analog input’s value

and the ratio channel’s set point.

c. Set the Min Set Point to the lowest set point value the

ratio channel should ever have.

d. Set the Max Set Point to the highest set point value the

ratio channel should ever have.

Set Point of the Ratio Channel

(Engineering Units)

Max Set Point

SP Offset

Sensor

Master Channel’s Process Variable

Sensor

Min Set Point

High

Range

Low

SP Offset + Master PV * SP Ratio

(Engineering Units)