Rockwell to GE

[Ron_Smith]

Just a couple of questions, I've been a Rockwell Automation enthusiast for years (Logix 500, Logix 5000), but I now have a lucrative offer with GE. Never written a GE Fanuc PLC program... but I've worked with many other platforms, PLC Direct, Mitsubishi, ect... any surprises to encounter? Can't imagine anything GE could throw at a programmer that Allen/Bradley hasn't already, but I figured I would ask anyway.  ?

Of course I'm going to do the necessary homework, just figured you guys could help me dodge a few curve balls. It's all CNC control and basically troubleshooting the machinery... improvements to enhance productivity will come later. 

Be gentile... I'm an Allen/Bradley guy sticking his toe into GE waters... Lol. ?

Ron

[Steve Bailey]

Will you be working with GE/ GE Fanuc PLCs or the ladder logic in the CNC controllers? GE and Fanuc went their separate ways at the end of 2012.

The biggest hurdle to overcome when moving to a new brand is the tendency to try to make the new platform behave like the one you're already familiar with and the frustration when it refuses to.

The GE 90-30 is similar in capability to the SLC500 platform. The Rx3i is similar to the CompactLogix. The VersaMax platform is similar to the Micrologix line.

The curveball you're most likely to encounter first is that timers in GE don't have a .TT or a .DN bit associated with them. You place a coil instruction following the timer and that serves as your .DN bit. If you absolutely, positively have to use the .TT bit, it is the most significant bit of the third %R address associated with the timer. Also, the first of the three %R addresses used by the timer corresponds to AB's .ACC word and the second %R address corresponds to AB's .PRE word.

I have many years of experience with GE products, so if you come across some logic that you can't figure out, post it here and I'll try to help. Feel free to contact me by private message if your client objects to posting the code to a public forum.

[Ron_Smith]

Your questions are my questions. 

Sounds like it's an older GE Fanuc/PMC setup... this seems very similar to things I've done with ControLogix and Kinetix 6000 multi-axis drives. Not getting much useful info until I can put my eyes on the hardware, but I appreciate your input! More to follow...

 

[Steve Bailey]

I don't have much experience with the ladder logic in the Fanuc PMCs. I only have hands-on experience with a few and in those cases there was also a PLC involved so I never had to modify the ladder in the PMC. The part programs in those controllers are written in G code.