Omron Sysmac CJ Series, Operation Manual

Page: 91 / 117

68
Shifting the Input Value (Input Compensation) Section 4-1
4-1 Shifting the Input Value (Input Compensation)
• 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.
• The initial setting of the input compensation value is 0.0 for all loops.
Example Application
1,2,3... 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.
Temperature
Upper
limit
100% FS
After
compensation
0
Input
compensation
value
Before
compen-
sation
Input
(C) Workpiece temp.
(D) Temperature sensor
(A) Temperature
Control Unit
Unit’s temperature
reading (A)
(B)
Thermometer
100
Furnace
Temperature after
compensation (e.g., 120
°
C)
Adjusted Temperature Readings
Temperature before
compensation (e.g., 110
°
C)
Input compensation value (e.g., 10
°
C)
After compensation
Before compensation
Thermometer reading (B)
System Configuration
SP region
(e.g., 120
°
C)
Lower limit input
compensation value
(e.g., 10
°
C)