PNP/PWM guidance needed.

Hello everyone.

I took on a project in order to improve my programmning skills, but I have seemed to stumble across something that is beyond my knowledge.
Basically I am building a controller for a 230 V motor and an encoder for the motor in order to control the movement of the motor.

I found an old inverter scraped from another project, which seems to be able to be controlled by 10 V.
As this is a somewhat old inverter the information avaible on the internet is limited.
I managed to find the datasheet of my specific model, from where I understand how to use the PWM signal to set different paramters in the functions. What I dont understand is how I am to chose what function/program I will be setting my PWM signal within. THe signals it's feeding is PNP.

PWM signals are pretty new to me, and therefore I am not sure if theres is something essential I am missing from the datasheet of how to set the different programs. If someone would have time to glimpse through the datasheet from about page 30-45'ish and give me an opinion or give me a wink in a direction as I have come to a dead end.

The specific model of inverter from where page 30-45 describes the funtions and how communicate with the inverter. But I found a better described version that has same firmware as my specific model.

Better description but not the exact model(Chapter 4):

Any help appriciated and don't hesitate with questions :slight_smile:


Page 30- and chapter 4 seem to be about setting the functions on the inverter with the keypad. No Arduino required.

This is a variable-frequency drive or VFD. You would not normally send that PWM as it is doing the frequency chopping itself.

A PNP transistor would be used in this context as a "high side switch". It sends 10V or 24V to the device to tell it that you want it to do something. The Arduino can't switch anything higher than 5V so you need more transistors to be able to turn the 10V PNP transistor on and off. If you can switch to NPN mode then that's simpler: only one transistor required.

Hello, thx for the reply, i really appriciate it!

I am aware that most of the pages reffer how to program it by keypad, but as I can see this is the only place from where anything related would be. Looking at the other datasheet, it seems to be implied that one chose from these functions where to feed it information from , but I cannot imagine any way that the inverter could actually recieve this info f.x.

1.) F04=000, inverter is controlled by keypad.
2.) F04=001, inverter is controlled by external terminal.

But from your answer im seeing that my understandig was not quite right of how it is operated, so ill hook it up to power and an oscilloscope to get a proper understandig of how this thing actually works.

I am aware that I need to amplify the signals coming from my arduino and the signal has been amplified, but ill try to play around with different signals.

But I think I need to play around with it a bit more to get a greater understanding from what is going on. As of now I am inclined to believe that this inverter is not as "smart" as I originally thought, and therefor the inputs of the inverter can only be used to set parameters within the functions, so to control it i would have to chose the function of the inverter and then let my arduino do it's magic from there. Correct me if im wrong :slight_smile:

Thx very much, keeping my occupied during christmas break. Appriciate it.