Dillemma: DC Motor Control vs. Torque Sensing

[ndzied1]

The Pico GFX-70 has a PWM output already if that is the model you were looking at. I have used it to drive stepper motors through a drive.

It has ramps but you cannot change a motion on the fly.

 

[JonHopper]

The GFX70 is unnecessary for our application as the HMI is going to be done separately anyways. The standard Pico controller has been what I've been looking at.

I've got a quick question about the Pico, if anyone has much experience with it. From the AB site i've gathered that it has very limited possiblities when it comes to ladder logic, namely its limited to 3 input conditions and 1 output per rung. However the new picosoft pro 6.2 software says it allows the Pico controllers to have much more complex diagrams. Does anybody know the limitations on ladder logic programming for the Pico controllers with the newest (or newer) PicoSoft Pro software?

 

[ndzied1]

The best place to get information on the pico is probably here:
http://www.trainingscenter.moeller.net/index.html

It is made by Moeller/Eaton and branded by Allen Bradley.

 

[Peter Nachtwey]

Why didn't you say you were designing a product?

In that case copy as much as you can from a kit and you can afford to put more time into the development of the product and it sold many times verses a system that is sold once.
Go here
http://www.ti.com/corp/docs/landing/f280xx-piccolo/index.htm
We bought a kit that had two DC motors and the source code to make it run in a few different modes. Our kit cost $400 but it is worth it. THe clark and park algorithms are already coded. The schematics to the board are provided. Just copy and modify for the application. Chances are you will not need the PLC unless you need something that is field programmable.

I didn't find the same kit that we bought list on this web page. You may need to look a bit. Also, TI has lots of good info in their application notes area. I know they have an application on BLDC PWM control.

 

[JonHopper]

Thanks a lot for the information, I will look around for the kit you're talking about.

The only reason I need a PLC is that the control program is going to be slightly more involved than I originally thought, plus a lot of the motion controls and force / torque sensing I will be doing is going to be experimentally calibrated and I am going to need to program and reprogram this thing quite often when I am in the shop with the first prototype.

The Pico is too limited, 3 contacts and an output per rung will not allow me the functionality I need. I'm currently looking into other options, and let me tell you, I had no idea there were so many different PLC companies. Thanks for the help everybody.

 

[ndzied1]

I think someplace like Newark.com would have kits like this.

When we use the pico/easy we just organize each complicated rung into a series of shorter conditional rungs. Depending on how many rungs you have it's not as limiting as you may first think.

But for sure, something like a MLX would be easier to work with...

 

[JonHopper]

MLX is too expensive, although I would like to use rslogix as it's what I am comfortable programming with.

I've decided to go with AutomationDirect. Either a CLICK or a DL06, haven't quite decided yet... I'd really like not to pay $400 for programming software... I'm just doing a bit more research on the CLICK to see if it will work properly, but as of right now, it looks like it will. The only thing I am concerned about is the analog input module. Does anybody have experience with this? I suppose I should start a new thread...