Analog encoder and v570

[Gregor]

Hey smart people

I need to update an old machine. In that machine is an electric motor which is controlled by 2 contactors to spin CW and CCW. The motor pulls up or put it down a metal rail. I need to control that motor with PLC. This is already done but with buttons, and now they want to set the distance.

Exemple: in position 1 need to be in upper position, position 2 is middle, and 3 is down.

I have an analog encoder RM36Cx, here is a picture on output signal.

The motor does 5,5 turns from upper position to bottom position, bbecause of this I have360° encoder

Any idea on how to implement in PLC program? This is first time I doing something like this, so any help is welcome.

Thanks

[Joe Tauser]

You'll need to set up and analog input in the PLC and use comparison blocks to control your outputs.

If you don't have any PLC experience, I'd start by downloading the Visilogic software and spending some quality time looking at the tutorial videos-

https://www.unitronicsplc.com/videos-and-tutorials-visilogic/

You'll need to pick a PLC model to do this.  Look at the models available based on I/O and what screen size you want.

Joe T.

[kratmel]

You must do some investigation of your system:

- how long is travel distance?

- is it brake used in motor setup?

- is it overtravel present after motor stopped?

- what +- distance error is possible in new application?

 

You need to build absolute positioning system - after sysytem restart with one turn linear encoder used in 5.5turn setup - you  need to set "zero" position.

Is it possible to use homing in your system?

 

As for me - using of direct linear potentiometer - is the best solution.

https://www.ebay.com/itm/Linear-Potentiometer-Position-Travel-Sensor-with-Rod-End-Joints-0-to-8-Range-/331032223707

You must calculate real resolution in your setup and ask customer about needed acсuracy.

Use your encoder is also possible, but you must solve some not simple logic and learn how to calculate position in simulated multiturn encoder.

 

 

 

 

[Gregor]

Hey all

 

I did a little work from my first post

Will this work?

 

In program we have 2 examples. One is top rail and one is side rail. 

Top rail need to do around 5turns of shaft to come from upper position to bottom, and side rail needs only 1 turn.

I attached the program and the wiring diagram for end switches.

TEST_formum ANG.vlp