I/O System Recommendations

We are looking to add a 16 tank farm, which will include a CIP set and a valve matrix of approximately 80 valves.

Our existing tanks do not use a matrix, so the I/O count is relatively low and is accomplished using a few POINT I/O racks, each with about 20 modules and configured in a ring. Control is done with 1769-L33ER.

The matrix will require 480 DI and 240 DO (3 DO actuation, 6 feedback per valve). Since POINT only offers up to 8 point modules, I think I need a solution with higher I/O density, ideally 32. So here is where I have some questions:

For this project, I'll need a controller with over 4MB program memory (we nearly maxed our 2MB). While the newer compactlogix controllers have this, there seem to be some compatibility issues with POINT IO and our 1769-L33ER CompactLogix controller according to this article: https://rockwellautomation.custhelp.com/app/answers/detail/a_id/772353 so I think sticking with the older line will be safer.

The older 1769 CompactLogix max out at 3MB which is insufficient. Instead I was thinking of using a 1756-L73 ControlLogix that we have on hand. I would just put the matrix on local IO, but the largest chassis is 17 slots and would not accommodate all of the matrix IO that I need. Can a ControlLogix directly control a remote CompactLogix rack? Am I wrong in thinking that I can put a bunch of CompactLogix modules on an adapter and treat it like a higher density POINT I/O rack?

So in summary, does this set up make sense and would it be compatible with my existing system? Again, this will all be connected to the existing ring.


Thank you for your time.

For the valve matrix, go with AS-Interface and save yourself a lot of trouble.

http://www.ifm.com/ifmus/web/pmain050_010_010.htm

Two AS-I masters would take care of your valves (63 each) and then some, it's a 2-wire control network. Your valves would need AS-I modules in the heads.

I typically don't put analog on AS-I networks, just had some performance issues with it, but if you're just monitoring a tank farm you could get away with it.

Others with more experience can answer, but may I suggest that you contact
your local rep and have him bring their plc specialist there to see your setup and discuss the I/o to help define the scope and possible solutions.

james

Thank you for the replies!

The AS-I suggestion seems to be just what I need. I have no prior experience, but we do use AS-I on some of our conveyor systems, so its something I need to familiarize myself with.

The matrix we have is used from a dairy facility. There is a large (1.5 inch) trunk cable with drops to each valve with a 4 pin connector. I am not sure what I/O system this is. The connectors/cables are in bad shape so I figured we would replace them.

Any idea if this could be adapted to an AS-I network?

That is just a "standard" M12 connector, and isn't specific to any networking protocol.

Could be DeviceNet, do you see thick gray cable, or anyplace that says "DeviceNet"?

Could just be IO wiring...

Look at the valve control tops, if it's been used you may not have any option but what is there, unless you wanted to replace control modules (if possible). If there is an AS-I/DeviceNet control module in the valve, should be obvious.

AS-I cable is pretty easy to identify, typically yellow with a keyed shape to it. Look at the information on the link I provided earlier.

Perhaps I am thinking about this the wrong way, so correct me if I'm going down the wrong path. I have been perusing the link you provided, but maybe interpreting it incorrectly.

-I would need a AS-I master in my controlLogix chassis, likely the U71005 as it provides two masters. http://www.ifm.com/ifmus/web/asi-BplaneMasters.htm.
-The keyed yellow cable would then distribute power and communications to Field Modules.
-Finally, from each field module, a cable with M12 connectors would connect to each valve.

You're saying that each valve needs to have special AS-I control modules in addition to the field modules? Something like this?: https://www.alfalaval.us/products/fluid-handling/automation/control-unit/thinktop/

I looked over the matrix again. There is no branding on the cabling. What seems to be the control module is not well labelled, but it does have LED indicators for A and B. This would suggest AS-I addressing with A/B selector, correct? I have attached a few pictures of the module for reference. Per assembly, there are three of these, one on the top, bottom, and drain.

My hope would be to have the matrix on a self contained AS-I network adapted to our Ethernet/IP, while the tanks and CIP set would be on POINT I/O to keep that standard throughout our facility. (So just digital IO on the AS-I)

Thank you for your expertise!

Those pictures are hard to tell for sure if it is an AS-I top or not. Thinktops would be AS-I capable, same with GEA Tuchenhagen TVIS, Sudmo...etc

I prefer the AC1422 master, it's a dual master so you would only need 1, plus it's Ethernet/IP so it can reside in a control panel near the manifold rather than at the ControlLogix panel. You want it mounted as close as possible as distance considerations do come into play. It also requires a specific power supply, probably the AC1258 if you go dual masters .

You also need flat cable to M12 connectors, and short M12 cables from the flat yellow trunk to the valve. NOTE: If you get really creative with the trunk layout, you can skip the small M12 cable and go truck --> flat to M12 connector --> Valve top.

EDIT: You'll also want a hand held addressing tool. I always buy one for a project, and leave it with their maintenance team after commissioning.

Paully's 5.0 proposed AS-I networking should be viable and I've seen it done frequently; it would be the most cost efficient solution save the kinda steep learning curve for first-timers.

I would personally go the AB way.

If you have a bunch of 1769-I/O32 modules (15 Input and 8 Output), a couple of CompactLogix power supplies and a 1769-AENTR sitting around you could run them off a 1756-L73 via a 1756-EN2TR EtherNet/IP bridge; you will need to setup two banks, one with 11 modules + the 1769-AENTR + PS and another one with 12 slots + PS (expandable up to 16).

However, why not go entirely PointIO? You are going to use a 1756-L73 (no known PointIO issues) and you could run up to 64 modules for each PointIO bank (1734-AENTR + PS); 8 x 64 = 512 IO points for each bank.

You could either add another 1734-AENTR for another 64 module bank or you could use a bus extension cable (1734-EXT1(3) and add another PS with a bank of 64 modules to the existing EIP 'Rack'.

The 'footprint' of 4 PointIO adjacent modules is smaller than the one of a 32-point 1769 module and the implementation costs are significantly lower.

dmargineau said:

I would personally go the AB way.

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Curious, how would you handle the actual physical installation? That is a a huge manifold, and each valve would require multiple cables (4 conductor for solenoids, 8 conductor for feedback). Cables would probably be installed in tray cable, so they needed to be rated for that, and wash down.

That is a lot of cable, and I don't think you could run everything back into a single panel location without creating a traffic jam. You would have to split the IO racks into multiple panels to distribute the cable efficiently. Even then, seems very expensive in cable and labor for the install.

Too many questions

Why does it all have to be home runs? Why not have one small I/O panel for each, say, 2 or 4 tanks? Would the added cost of a panel + AENT be more or less than the cost of the cable + trays/conduit? We know nothing of the physical layout. One advantage of a distributed system is that you can LOTO one section and still keep running on the rest. How often is this needed? Dunno.

How many spares are needed? What is the likelihood that instead of 5 valves per tank, someone someday will want a sixth?

What kind of valves are these (and why 3 DO per valve? Open/Close/Lift?). If they're solenoid, maybe something like an SMC EX260 can handle the DO load and even the DI.

There are many ways to skin this cat. All will work. There may be a "most cost effective" solution out there, but how much money will be spent chasing it? And in the grand scheme of design + installation + maintenance, how much does saving a few hundred bucks on the hardware really matter?

Aardwizz said:

Why does it all have to be home runs? Why not have one small I/O panel for each, say, 2 or 4 tanks? Would the added cost of a panel + AENT be more or less than the cost of the cable + trays/conduit? We know nothing of the physical layout. One advantage of a distributed system is that you can LOTO one section and still keep running on the rest. How often is this needed? Dunno.?

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The biggest hurdle is this 80 valve cluster, this is a large amount of IO in a very small space.

Aardwizz said:

How many spares are needed? What is the likelihood that instead of 5 valves per tank, someone someday will want a sixth?

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+1 for a networked option

Aardwizz said:

What kind of valves are these (and why 3 DO per valve? Open/Close/Lift?). If they're solenoid, maybe something like an SMC EX260 can handle the DO load and even the DI.

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Probably a mix-proof/PMO (Pasteurized Milk Ordinance - US). These valves will have solenoids and FB devices all contained in the valve top hence the large IO count. 3 DO - Main Valve actuation, Upper Seat Lift, Lower Seat Lift. DI would be the associated feedbacks.

Aardwizz said:

There are many ways to skin this cat. All will work. There may be a "most cost effective" solution out there, but how much money will be spent chasing it? And in the grand scheme of design + installation + maintenance, how much does saving a few hundred bucks on the hardware really matter?

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OP needs to figure out what type of valves he actually has since its purchased "used". That will limit his options. If he has DeviceNet or AS-I control modules in the valves, there is your answer. If not, discrete IO wiring it is.

Paully's5.0 said:

Curious, how would you handle the actual physical installation?

That is a lot of cable, and I don't think you could run everything back into a single panel location without creating a traffic jam.

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A Point I/O 'Rack' could contain up to 99 modules (792 I/O) which can be 'split' in up to 5 banks using Expansion Power Modules (1734-EP24DC) and 3 or 9 foot Expansion Cables (1734-EXT1-3); several adjacent enclosures should be able to mitigate any cabling/wiring installation issues.

Dryhops,

In my past experience I would try to stay away from networking the valves. One cup of water may take the whole network down.
Generally mixproof valves only have 2 solenoids per head- Valve divert and seat lift (this will be commend with other valves in the circuit with airlines).
The feedback is usually only valve diverted as the seat lift is only pulsed for a short duration

I am tumbling with the same decisions, I need to setup remote IO in a large production area, probably looking at around 200 inputs and 80 outputs, 10% will be analog.

I will be using a compactlogix L3 processor but are not sure what remote IO system to go for, my gut feeling is to stick to DeviceNet and Flex IO, i know this inside out and has been using this (seems like all my life) so the thought was if there was something new and better on the market, my local sales rep. is not the sharpest (they read about a PLC's in a magazine)

But all the new stuff I see coming out are all with connectors, I have never understood the need for this in the field, cables never have the right length

PS: My installation is in a very corrosive environment, with water, salt and various chemicals in the mix.

What do I do, stick with the good old stuff ??

Use Ethernet IP remote I/O - way to go. I am using Omron but AB, Schneider and the like have it available as well. Works great - have used it on about 40 projects now without issue.