Shifting The Input Value (Input Compensation) - Omron CJ Series Operation Manual

Shifting the Input Value (Input Compensation)

4-1 Shifting the Input Value (Input Compensation)
Example Application
1,2,3...
68
• The input value is shifted by the "input compensation value" for all points
in the sensor's range. For example, if the input compensation value is set
to 1.2 ° C and the original process value is 200 ° C, the value after compen-
sation will be 201.2 ° C.
Temperature
Upper
After
limit
compensation
Input
compensation
value
0
• The initial setting of the input compensation value is 0.0 for all loops.
1. In the following diagram, the temperature sensor is some distance from the
workpiece that is being controlled and the reading from the temperature
sensor must be adjusted to reflect the actual temperature at the workpiece.
(The reading from thermometer (B) shows the true temperature at the
workpiece (C).)
2. The input compensation value is just the difference between the work-
piece's temperature (B) and the Temperature Control Unit's reading (A).
Figure 2 shows the process values before and after compensation.
Input Compensation Value = Workpiece's temp. (B) - Unit's reading (A)
3. After setting the input compensation value, compare the temperature dis-
played on the Unit (A) with the temperature indicated by thermometer (B).
The input compensation value is correct if the two readings are approxi-
mately equal.
100
(B)
Thermometer
Unit's temperature
reading (A)
Temperature after
compensation (e.g., 120 ° C)
Temperature before
compensation (e.g., 110 ° C)
Lower limit input
compensation value
(e.g., 10 ° C)
Adjusted Temperature Readings
Before
compen-
sation
Input
100% FS
Furnace
(C) Workpiece temp.
System Configuration
After compensation
Input compensation value (e.g., 10 ° C)
Before compensation
Thermometer reading (B)
SP region
(e.g., 120 ° C)
Section 4-1
(D) Temperature sensor
(A) Temperature
Control Unit