Tshabalala

Hi, I am trying to control the speed of the Danfoss VLT drive using the LOGO8! PLC. I run the simulation but the drive is not accepting the speed reference I give to it through the softcomfort on simulation.

My 4-20mA output is connected to pin 53 as per datasheet of the VLT drive.

The aim is to have the HMI screen to vary the speed while connected to the LOGO.

I use LOGO!Soft Comfort V8.3 for the circuit diagram on the LOGO8! Standard OBA8

HMI Simatic KP 700 comfort

I have attached my program example.

Your assistance will be highly appreciated.

You write you use a 0BA8.Standard LOGO!.

But in the screewnshot is it a LOGO!8.FS4. 

The simulation in LOGO!Soft Comfort only works on the PC.

How is the real LOGO supposed to output a setpoint?

The 4-20 mA analog input is by the PINs 55 and 60.

PINs 53 and 55 by 0-10V.

I don't know what's then exactly is your problem.

Have you measured the current of the AQ2 output? 

Want you only give a setpoint (0-100%) from the HMI to the analog output?

Or want you use a PI controller, by using a analog input as feedback and set the setpoint for the Pi controller from HMI?