Best Used Robotic System for Computer Interface

[rljohns]

Feel free to move this post if it's in the wrong place!

I'm a graduate student looking to buy a used robot for my thesis work.  I've worked with both ABB and UR systems in the past (new systems), communicating primarily via ethernet connection.  I won't be doing a lot of the same task over again, but rather, would like the flexibility to generate robot commands from CAD programs and to integrate sensors/feedback loops, etc.  With newer systems, this is a pretty straightforward process:  I just generate a text file with robot script (generally a lot of "movel" commands with some additional I/O), send it to the robot at a given port and wait/react to sensors on the PC side.

Now, however, I'm looking to get a system of my own, and have a very low budget (around $8000).  It would seem that based on that price range, I'm pretty much limited to used Nachi and ABB systems.  My question is, can anyone provide any information or advice on PC integration into older systems? 

What I can gather (from speaking with ABB reps) is that I would need a controller that is at the S4C+ or newer generation with an ABB to make this happen.  Before that it seemed it was all serial communication that would limit potential data trasfer/speed (but these older systems are much more in my price range).

On the Nachi side, I spoke with a rep who said this type of interface wasn't possible on any of their controllers (AW or AX), but I have a hard time believing this.  Does anyone have any experience with PC interfacing with an AW control?

Any advice of information would be very much appreciated.  It's rather difficult to find information on the potential for interface with these older machines, especially given price and tolerance requirements.  Any experience whatsoever would be great to hear!

[TygerDawg]

Too bad your budget is so limited.  Staubli CS8 systems would be much better suited for what you are trying to do because of the powerful VAL3 language and wonderful connectivity through ethernet.  Used CS8 systems are rare, but one occasionally finds them at auction.  The older CS7 versions are almost as good, but then you would face possible spare parts & support issues.  Adept & Epson have smaller 6-axis systems with good controllers.  If you don't need 6-axis motion and only want to develop algorithms, then perhaps you might consider Adept/Epson/Yamaha SCARA systems with their powerful languages and connectivity.