Omron E5ZN - Page 58

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Shifting Input Values Section 4-1
3. After you have set the input shift values, check Controller readout (A) and
control target temperature (B). If they are almost the same, the tempera-
ture input shift value is correct.
Figure 2 One-point Temperature Input Shift
Two-point Shift Use two-point input shift if you want to increase the accuracy of the readout
values across the range of the sensor.
1,2,3... 1. The Controller readout will be shifted at two points, near room temperature
and near the value at which the temperature of the control target is to be
controlled. For this reason, bring the control target temperature to near
room temperature and to near the SP, and check the control target temper-
ature (B) and Controller readout (A) at both points.
2. Using equations 1 and 2, calculate the upper and lower limit temperature
input shift values from values obtained in step 1.
Figure 3 shows the effect of using two-point temperature input shift.
Figure 3 Two-point Temperature Input Shift
• Use the following equation to calculate the lower limit temperature input
shift value.
• Use the following equation to calculate the upper limit temperature input
shift value.
3. After you have set the calculated values for the lower limit temperature in-
put shift value and the upper limit temperature input shift value, check the
Controller readout (A) and control target temperature (B) at both points.
Controller readout (A)
Temperature readout
after shift (e.g., 120
°C)
Temperature readout
before shift (e.g.,
Lower limit
temperature
input shift (e.g.,
10
°C)
After shift
Upper limit temperature
Input shift value (e.g., 10
°C)
Before shift
Temperature readout of
control target (B)
Near SP (e.g.,
120
°C)
0
Set temperature upper
limit YH (e.g., 260
°C)
Controller readout (A)
Temperature readout
after input shift X2 (e.g., 110
°C)
Temperature readout
before input shift Y2 (e.g., 105
°C)
Temperature readout
before input shift Y1 (e.g., 40
°C)
Temperature readout
after input shift X1 (e.g., 25
°C)
Lower limit temperature
input shift value
0
After shift
Before shift
Upper limit temperature
input shift value
Temperature
readout of control
target (B)
X1 room temperature
(e.g., 25°C)
Near X2 SP (e.g.,
110
°C)
Set temperature
lower limit YL
(e.g., 0
°C)
YL
− Y1
Y2 − Y1
× {(X2 − Y2) − (X1 − Y1)} + (X1 − Y1)
Equation 1
YH
− Y1
Y2 − Y1
× {(X2 − Y2) − (X1 − Y1)} + (X1 − Y1)
Equation 2