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.