AutomationWizard

Yes, you can just stick a 0 in tieback. Your setpoint can be moved into the data structure PD10:0.sp if you're using a pd file type, or look up the word number if it's an integer type. I would not use a PID for this. I would use 100% speed till I got close and then a slow speed till I reached total weight minus some pre-act value. I would also put in some code to adjust the preact value for the next run by 1/2 of the error, so long as the error was within some pre-determined boundries. Using a PID will just screw up and slow down your process.

The very first step of this process is to make a detailed process diagram...

The slot in my M20 works fine. I was a little stiff the first time I put my PCMK into it.

Are you sending an analog signal to your heater or digital? What kind of tollerance do you have on the temperature control?

Kep is the OPC used for connecting Eaton Panelmates to PLCs. It definately works with Allen Bradley. I think Rockwell even sells a version of it.

If all else fails, copy your logic to a new project and download. I had a PLC5 project that was corrupt, and making a new project and copying the logic into it was the only fix that worked. It was doing some very strange things with the IO.

I can't tell for sure from reading your post, but can you see where the data is supposed to be? Is it evident on the client side that something has changed? If you can't tell, then maybe you have two servers and your clients are looking at the other one. Otherwise I'd be looking for some sort of tech note about deleting client cache files. I haven't used ADS since 6.3 because it doesn't work very well.

It sounds like you are using a time proportional PID configuration to create discrete pulses of duty cycle determined by the PID instruction. This is a very good technique. You can probably improve your control with better tuneing of the PID. For more information on PID tuneing from someone who is an expert, see the web site at http://www.controlguru.com/ . You can also change the cycle time of your pulses. Shorter cycle time will likely lead to better control as long as it doesn't get faster than the switching time of your output circuit. There is PID tuneing software called RSTune available from Rockwell, but it isn't a guaranteed fix. You might also want to look into something called pulse width modulation.

16 bits of sequenced data? 16 words of sequenced data? Either way the 1200 should handle it fine if it has enough I/O. AB has the SQO sequencer instruction, but you don't need to use it. Just use an integer for the step the sequencer is in (N7:0), place all your sequencer data in seperate files (say N10 for first 16 bits, N11 for next, etc...), use indirect addressing to mov the data for each word (16 bits) from the data file (N10) mov N10:[N7:0] N7:1, mov N11:[N7:0] N7:2 etc... for each 16 bits of sequenced data. If your IO config and budget allow, consider the 1100. Ethernet comms is much better than DF1. It doesn't have the IO capacity of the 1200 though so be careful if you are using expansion cards.