Control stepper motor pump with Arduino Uno, Current/Voltage signal, Square wave

Projects General Guidance
1

Hi all,

I am planning to control a pump (KNF, FEM 1.02 TT.55RC, see link) with my Arduino Uno. It came with a controller (see page 9 link) but this controller needs signals to start the pump. I can either send a 4-20 mA or a 0-10 V analogue signal. Also, a continuous start signal is needed as the pump will not start without that signal. The dispense stroke will start at the falling edge of a signal. I used a simple switch and connected COM pins 2 and 8 on the controller but this will only make the motor rotate for a portion of a revolution and then stop. So I kind of need a signal that simulates that switch frequently which, I guess, is a square wave function.

So my first question is: is it possible to send a 4-20 mA or 0-10 V signal from the Arduino the the controller to control the speed of the stepper motor? If yes, how?

And my second question is: Is it possible to use the tone function to create a square wave signal which will make the pump run continuously? If yes, how would I have to connect it to the controller and what frequency would be best (I guess as high as possible?)? If not, what would you suggest instead?

I have a 24 V, 1 A power supply for the controller and a 9 V, 500 mA power supply for the Arduino Uno. If I get this to work I am planning to control the pump with LabVIEW. For this reason, I have already written software that can control the speed of a stepper motor connected to an Arduino.

Thanks a lot in advance!
Please let me know if you need further information.

ProTob

2

Before getting into your specifics, allow me a question. If you want the this pump to output fluid continuously, why did you buy a precise, single shot pump? Just curious.

Trying to create a compatible programmable analog output from and Uno will require additional components as you must first convert the PWM output to a voltage and then either level shift to 10 volts or convert to 4-20ma. The 0-10 volt version is easier but requires use of the 24vdc supply. Creating 4-20ma can be done with Uno's 5 volt supply but it requires a few more components due to the current source.

Ultimately, you can probably connect the 0-10 volt reference input to 10vdc (using a TL431, LM4040 or other means off of the +24 supply), thereby setting to the maximum metering stroke and then controlling the frequency of the square wave going into the START input put to give the desired flow rate.

3

We got this pump because we are hoping that this pump flows without significant pulsations.

What specific components would be needed?

Sorry I can not quite follow you there. Could you explain this to a beginner? Thanks!
How would you create the square wave?

4

This pump dispenses doses of a liquid by use of a diaphragm, i.e. in strokes. The analog signal tells the controller the amount to dispense, and the Start signal ejects just that dose.