Signal conditioning and hardware-software scaling with acecatech App

Here we are given a transmitter that transmit current signal 4-20ma, we are to interface with a PLC that accept 0-10v only. we are going to demonstrate how we are going to condition the analog current signal and convert the current to voltage signal as well as compensate for this in the software scaling all with the aid of the ACECATECH Application 1.3 and 1.5.

first of all we scale and convert our analog current signal to voltage signal using acecatech App 1.3. the circuit for this signal conditioning is already provided. What we are going to do is to enter our parameters and generate values for our new voltage range, our resistor as well as its power dissipation.

current to voltage hardwar

enter all the parameters . ie current iput range: 4-20ma, controller voltage range 0-10v

we obtain the following results
new voltage signal lower range: 2v
new voltage signal upper range: 10v
resistor resistance value: 500Ohms
resistor power dissipation: 0.2W
Hence we need a shunt resistor of resistance 500ohms and power dissipation of 100mw across the PLC . We are advised to use a precision resistor so a resistor of 1/4W, 500Ohm 0f 0.1% will be OK.
we are also advised that the new range does not scale completely to the controller’s range and we may loss some resolution as much as 20% (that is design for you, yuo loss some and you gain some) and we will be needing ACECATECH APP 1.5 for hardware-software intermediary scaling. so we proceed with this in our next step.

Our new scale of 2-10v does not exactly match the PLC 0-10v resulting to the loss of bit resolution to a maximum of 20% as explained previously. this will accordingly result to error of equivalent magnitude at the lower range of the signal. hence the compensatory re scaling at the software level.
we enter our parameter including the raw input range for our PLC which we will assume 0-27648 for a s7 1200 Siemens PLC with 16 bit resolution. we go to ACECATECH APP 1.5
we have the following results.
upper range of controller New raw value: 22118
lower range of controller New raw value: 5530
so we use this range as the range for our raw value in our PLC program.

for inquiry or consultation you can mail: