Dear all,

Is it possible to make mathematical equations in LOGO?

I have a temperature sensor connected to the logo (4-20) mA.

0,1 mA = 0,78°C

I need to bring a value X to the screen which is:

X = 28 . (1 + 0,00336 . Temperature value)

Thanks for the advice.

Thanks for the reply.

4 mA = -25°C

20 mA = 100°C

Linear correlation.

In fact the formula is:

But you can rewrite it as:

X= 28,084 .[1 + 0,0336.T +

(0,0336.T. 0,0336.T)/2 +

(0,0336.T. 0,0336.T.0,0336.T)/6 +

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T)/24 +

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T.0,0336.T)/120 +

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T)/720 +

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T)/5040 +

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T)/40320+

(0,0336.T. 0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T.0,0336.T)/362880]

So, a lot of calculations to get a precise result. I think this will not possible in LOGO?

There is a linear correlation between the analog input and the temperature conversion.

But there is a non-linear correlation between the X value and the temperature value.

In the formula you can see this is an e - function.

It's the X value I have to bring to the LOGO screen.