Technote #11 - Determining the PLC Tools SIM-ALP2 0-20mA Engineering Units from 4-20mA scaling parameters
The SIM-ALP2's mA Engineering Units are based off of a low scale value at 0mA and a high scale value at 20mA. To determine the 0mA value based off of a 4-20mA range use the following calculator or the formula below the calculator.
Milliamp mA Scaling Calculator
Engineering units at 4mA:
Engineering units at 20mA:
0mA value =
Formula to calculate mA scaling
- Eu = Engineering Units
- Eu0 = 0mA Engineering Units
- Eu4 = 4mA Engineering Units
- Eu20 = 20mA Engineering Units
Eu0= Eu4 - (Eu20-Eu4)/4
Eu0= (Eu4 *5 - Eu20)/4
Both do the same.
Example 1: You need to simulate a pressure sensor that outputs 0-100psi.
Eu 4mA = 0, Eu 20mA = 100
Eu 0mA = -25
Example 2: You need to simulate a length measurement sensor that outputs 100-300 inches.
Eu 4mA = 100, Eu 20mA = 300
Eu 0mA = 50
Once you have calculated the Eu 0mA, simply enter this in the Low Scale and enter Eu 20mA in the high scale.