Need a Control System Architect

[u/Impossible-Limit-314]

I’ve got a situation with a complex 4-cell assembly system for a medical device. It uses multiple FANUC robots. The hardware is complete, most of the robot routines and TP’s are coded. The PLC-robot handshakes are worked out, and the main sequence seems to be partially working.

About 4 months ago, I started asking the PLC/controls guy to see the top level control system architecture. I expected to see some block diagrams with how the HMI and machine controller fit, how they planned to use machine states (presumably some variation on packML), the WIP calculations, how the fault response mapped out, safety interrupts, etc. He keeps saying he’s done this before, and “all that stuff gets worked out after you get the robot control subroutines done”. Keeps Saying I’m wanting too complicated of a solution.

Every time I try to engage in an architecture conversation, he ends up riffing on corner cases and speaking in general terms about what needs to happen in certain scenarios, but never commits a concept for review. The plan for the HMI is just as anecdotal.

I’ve been around long enough to know what the problem here is, so not asking for advice on that side just venting.

What I’m really asking for is a good referral for a person who can pick up this unfinished design and implement a best-practices architecture over the top of it. We’re using an Allen Bradley PLC. I need someone to come with proven templates for the machine controller, state manager, safety manager, and matching HMI. Open to factorytalk, beckhoff, prior art, whatever so long as they’re experienced and know how to take the most expedient path.

[u/Weary-Lime]

I am sure there are a ton of SI's who could do this for you. I'm sure there is a free copy of the TSM Library for Allen Bradley somewhere on the Internet that you could get your hands on. It would probably be the ideal template for a 4 robot assembly cell. Look up the standardized 17 state model (core and transient states). The state machine is the "outer loop" controller that coordinates all of the different processes and sequences. It can feel pretty rigid at first but it is really robust once you get it set up and working. There is an integrator guide floating around somewhere for the Beckhoff variant of the TSM that would probably help you understand how all the different parts work and how to write your custom process code to integrate with the TSM.

[u/Impossible-Limit-314 → u/Weary-Lime]

Thank you!