Direct Logic 205 PLC controlling a stepper motor to be controlled by an Analog Voltage

[RPosty]

Looks like I got in over my Head, I had used Click PLC's before so thought I could handle this project.

Goal: Use a capacitance sensor module that produces a 0-10V signal to determine position and maintain it. The sensor uses an Analog output where 1V = 1mm. If has an Analog Input used as a reference. I put in 1V it will provide an opto output stating it is in position when the the output matches. it also has a Vdif analog output that is + or - the difference from reference.

So I purchased a DL205 w/ DL262 CPU, an F2-8AD4DA-2 for the Analog inputs and outputs. An H2-CTRIO-2 for the stepper control to control a simple Sure step STP-DRV-6575 with STP-MTR-23055 motor.

I Configured the workbench for a step and direction motor. Drive is set up and self tests fine. but I am having trouble on where to begin with the ladder. They have an example, but unless I purchase the full software, I can't open it because it is more than 100 words. I am guessing because of all the included details.

what I want to do is:
when above the reference voltage drive the motor until it is in position then maintain the position. sounds simple , but this manual looks like greek to me.

any tips you think will help me is appreciated. i will search these forums to see if its been covered

thanks so much


"I am stuck on Band-Aid brand, 'cause they are stuck on me"

 

[thebard3]

Sounds like a simple PID function should work.

Brad Waybright

It's all okay as long as it's okay.

 

[itsmoked]

First tip. Stay away from the DL series because you have to pay for the SW. :/

thebard is probably correct but to help you get off dead center I'd cobble some ladder logic up that is rudimentary, just run a straight Bang-Bang.

A: Read the analog data
Compare the read number to the desired number.
IF greater than reverse direction
ELSE don't reverse direction
GOTO A:

This will probably cause erratic control but from this you will get a feel for the dynamics and can quickly improve the control. From here you'd probably want to work in a PID. There are a lot out there to choose from find one for the DL series.


Keith Cress
kcress -

http://www.flaminsystems.com