Watlow CLS200 - Manual (Page 208)

Chapter 10: Linear Scaling Examples CLS200 Series User’s Guide
192 Watlow Anafaze Doc.# 0600-3050-2000
Example 3: A Pulse Encoder
Situation
A pulse encoder which measures the movement of a convey-
or is connected to the controller. The encoder generates 900
pulses for every inch the conveyor moves. You want to mea-
sure conveyor speed in feet per minute (FPM).
Setup
The encoder input is connected to the controller’s pulse in-
put. The INPUT TYPE for the loop is set to PULSE. A one-
second sample time gives adequate resolution of the con-
veyor’s speed. The resolution is:
A DISP FORMAT of -99.99 TO +300.00 is appropriate.
The input readings are as follows:
• At 0 Hz, the input reading will be 0.00 FPM.
• At the maximum pulse rate of the CLS200 (2000 Hz):
Table 10.5 Scaling Values
Parameter Prompt Value
High Process Variable HIGH PV 11.11 FPM
High Sensor Reading HIGH RDG 2000 Hz
Low Process Variable LO PV 0 FPM
Low Sensor Reading LO RDG 0 Hz
1 pulse
1 second
--------------------------x60 seconds
1 minute
---------------------------------x 1 inch
900 pulses
-------------------------------x 1 foot
12 inches
--------------------------- 0.006 FPM =
2000 pulses
1 second
----------------------------------x60 seconds
1 minute
---------------------------------x 1 inch
900 pulses
-------------------------------x 1 foot
12 inches
--------------------------- 11.11 FPM =