PLC Recomendations...

Hello again all,

i was looking for some recomendations on a job/jobs im working on. I was approved for 2 jobs with different time frames, first i was approved to upgrade the ficility from older AB controllers to ControlLogix, which i still have about 7 months to complete. More recently (yesterday) i was approved on 3 new block measuring machines. The current system i was working on was an old SLC 5/03 that had one DC input card (IV16) one DC output card (OB16) and a NI4 Analog card. the 5/03 had 8k memory which was not enough for one machine as there is 31 different size blocks all with its own tolerance limit for 9 points of data. so i maxed out my 8k, 16k would be perfect. Now this project is due near the end of May...now comes the fun part

keeping in mind that i am going to have to use whatever PLC i select here as remote I/O when i do the control logix switch, what are my options....

we have 3 lines with 3 analog laser sensors above each line (looking down), 1 computer running rsview32 and 3 monitors. (the computer with rsview32 is what they want me to use as HMI for all 3 lines.)I would also like all 3 stations linked together via ethernet.

at first i thought micrologix 1100 for each station, but when converting to CLX i will not beable to use this will i?? I just dont want to buy 3 plc's then have to throw them in a box a year later.

what do you guys think??? also sorry for the extremely long post, just trying to eliminate any questions about the job at hand.

juts so that I understand you correctly.
You need to wire 3 individual machines with its own i/o and CPU right now.
Later the i/o has to be connected to a central ControlLogix CPU as remote i/o.

Well, that sounds very reasonable. But that requirement highlights a huge gap in AB/Rockwells product portfolio.

If you use MicroLogix, you cannot really reuse code (not without a lot of adaptation), and you cannot reuse the PLC hardware.

If you use CompactLogix CPU and CompactLogix i/o, you can reuse the code, but you cannot reuse the 1769 i/o (because there is no adapter modules for connecting 1769 i/o to Ethernet/IP or DeviceNet).

You can use CompactLogix CPU and Point i/o via Ethernet/IP. Then you can reuse both code and i/o. Since you mention ML1100, I guess that this is way above your price point.

What AB/Rockwell should have done, was to have a small and affordable Point CPU that runs "real" Logix code for connecting Point i/o directly.
Similar to the now cancelled Flex CPU (which was too expensive).

Yes you are right where i am thinkin......the project engineer didnt really takin PLC into account when me put in his cap so now im dealing with limited funding. this is why i am thinking ML1100 but as you stated, it looks like it may be my only option, as they want to stay with AB plc's but what stinks about this is what i mostly need is my analog signal and the 1100 only has 2 analog inputs and that is voltage where i need current. so to buy the expansin aswell at $350 a piece im not even using much of the controller and to me just seems like overkill and a waste for a controller that will only be around for a year. not to mention theres 3.

Yes i could leave the controllers in just link them via ethernet to a switch that the CLX is on but then if there was a problem up or down stream the main plc woldnt know it...can a ML and CTLX talk to eachother?

can a ML and CTLX talk to eachother

Click to expand...

Yes. But only messaging. It is a cludge if you ask me. Not recommended for proces critical signals.

Get Point i/o.
Connect it to a single CompactLogix or ControlLogix CPU. If you have a spare CPU that you can use temporarily, it will not cost you that much.

ok so i just got word that they want to go ahead and get the control logix main station to control this project first. so i guess now the question is do i still get point i/o or can i just build a single rack that can run all 3 machines (now possibly 4)?

I would definitely put the i/o close to the machine.
So my vote goes to Point i/o.