Using a PLC to control an analog driver board

[hapetter]

Hi.
Im going to control a galvanometer (control of a mirror - set position (angle), set velocity, position feedback) with an analog driver board. The driver galvanometer is controlled like this:

analogue input (selectable +/-3, 5, 8 or 10V).

The position output is always +/-3V. Depending on the tuning, this corresponds to a certain scan angle. I.e. +/-3V are equal to +/-30 deg opt. Half of the command input signal results in half of the position signal and half of the scan angle. Also, depending on how your command input signal looks like, the scanner will react to it. I.e. if you command a triangle waveform with a certain frequency, the scanner will follow the commanded signal with a constant velocity. If you command a jump (step waveform), the rotor/mirror will also jump to a certain position (jump size depends on amplitude of your commanded step).

So my question is (newbie...).

I like constant velocity
Can I use a PWM signal? If so. Can you explain how to use this signal to set a setpoint (position) and velocity.
Should I control the position in open or closed loop?
How should I design (code) the driver output (+-10V) in software?
Thanks!

Best Regards
Hans Pettersson

 

[djs]

I looked at the manual you provide the link to. There are several inputs, one of which is the position command. This needs to be driven by a differential DC voltage. Total range is +- 3 volts. There is also a an output from the controller, differential +-3 volts for a position feedback.

First you need to you need to find an analog output card for your PLC that has differential voltage outputs. Most PLCs have differential voltage input cards.

Be aware that PLCs have an associated scan time. Outputs are updated at this scan time interval. Therefore any outputs will be stair case format.

 

[hapetter]

Thanks! I found out how to do