Prerequisites
Sensor: temperature sensor, measuring range –50 to 100°C
Temperature to be measured 25°C
Order of events with LOGO!Soft Comfort
The sensor converts the temperature from 25°C to a voltage value of 5.0 V.
LOGO! converts the 5.0 V to the standardized value 500.
Using the sensor and measurement range data, LOGO! ascertains the value 0.15 for the gain and the value –50 for the offset.
According to the formula:
Analog value = (standardized value x gain) + offset
LOGO! calculates as analog value:
Analog value = (500 x 0.15) - 50 = 25
Order of events with LOGO!
The sensor converts the temperature from 25°C to a voltage value of 5.0 V.
LOGO! converts the 5.0 V to the standardized value 500.
From the sensor and measuring range data you must establish the values for gain and offset.
According to the formulas:
Gain = (maxSensor – minSensor) / (maxnorm – minnorm)
and
Offset = minSensor – (Gain x minnorm)
it follows that
Gain = (100 – (-50)) / (1000 – 0) = 0.15
Offset = -50 – (0.15 x 0) = -50
According to the formula
Analog value = (standardized value x gain) + offset
LOGO! calculates as analog value:
Analog value = (500 x 0.15) - 50 = 25
Additional examples
Physical quantity |
Electric quantity of sensor |
Standardized value |
Gain |
Offset |
Analog value |
|
0 V 5 V 10 V |
0 500 1000 |
0.01 |
0 |
0 5 10 |
|
4 mA 12 mA 20 mA |
0 500 1000 |
10 |
0 |
0 5000 10000 |
|
0 mA 10 mA 20 mA |
0 500 1000 |
1 |
50 |
50 550 1050 |
1000 mbar 3700 mbar 5000 mbar |
0 V 6.75 V 10 V |
0 675 1000 |
4 |
1000 |
1000 3700 5000 |
-30 °C 0 °C 70 °C |
0 mA 6 mA 20 mA |
0 300 1000 |
0.1 |
-30 |
-30 0 70 |