Why does Contrologix seem to be unpopular?

[Alan Case]

I found the learning curve not that great. (to get started) I was able to start writng a working program within a few hours. The thing was now that I look back at it I realise I was not using the processor or the command set to its fullest potential. To become a guru can and will take a long long time because the package can do so many things in so many different ways. They will all give a result but there usually is a better way. Structure is so much more important than an SLC/PLC, both data and program structure. Regards Alan Case

 

[grs]

UDTs

Use UDT's and/or arrays to organise your data and RSLinx can retrieve them as blocks or they can be 'produced' as blocks.

FYI, I did a project a year or so ago that used UDT's for all transmitters and found out that there's a little checkbox in RSLinx that will allow faster update times for UDT's. Under 'Communications>Configure CIP Options...' select the 'Connections for ControlLogix Processor' tab and make sure you check the 'Optimize User Defined Data Types' box.

I saw a drastic increase in the update times on the HMI once I did this.

 

[akreel]

Using ControlLogix carries no obligation to use ControlNet - I prefer ethernet.

But, the ethernet connection still uses an Allen-Bradley message string. See Tom's comment on proprietary protocols. Some people think plugging a CAT5 cable into stuff makes it universally compatible.

 

[akreel]

Alan,

You read my mind. Getting a program started and making lights blink on and off is not too difficult. Of course, I've done some brand-hopping and I've become pretty comfortable with learning new software.

On our project, we will be testing those advanced/better methods you mentioned. I'm really excited to see what we can do!

AK

 

[Norbert J. Gallagher]

operator and dog scenario

Hopefully, the final result will be the operator & dog scenario: The ideal control room has an operator and a dog. The operator is there to feed the dog. The dog is there to bite the operator if he touches anything.


Ha, Ha, Ha!
I love it!

 

[Gerry]

?

But, the ethernet connection still uses an Allen-Bradley message string. See Tom's comment on proprietary protocols. Some people think plugging a CAT5 cable into stuff makes it universally compatible.

And, your point is...??

I prefer ethernet over controlnet because

• I don't need a special interface for my notebook PC - just use the built-in enet port or wireless
• I don't need a special interface for the HMI - just use the built-in enet
• I don't need RSNetworx to configure & schedule the network
• CAT5/RJ45 is easier to deal with than coax/BNC

 

[corkers]

Gerry,

I think you make very valid points here, but some important things to note, I disagree with your point on RJ45 CAT 5 being easier to deal with in my experience coax is far more robust, easier to terminate WELL, and are far less likely to interfered with by the IT department. Weve all had experiences with dodgy patch leads, roll your own etc...

The other important point is that many times ethernet interfaces are used over the corporate LAN, making it dependant on shareing the bandwidth avilable with all other users... not the most desireable. Not to say this is always done.

I think these to protocols complement each other very well and we specify that all PLCs be configured with ControlNET for remote rack comms, Ethernet for HMI/plantwide access (monitoring and programming), devicenet for comms to VSDs etc and DH+ /RIO for legacy comms with other PLCS/SCADA.

cheers

Corkers

 

[CaseyK]

My omly logical reasons are cost and unfamiliarity.

I can do as much with other branks of equipment (and usually more) for a lot less $$$. Last time I compared, GE was about 1/8 the cost of A-B.

I used A-B exclusive for eaight years. Budgets take over, about 25% demand A-B, 25% would like it, and 60% won't pay the extra.

Maybe someday someone will require it, I'll get to play with it, and I'll be a big fan.

until then, Brand GE, Brand X, or Brand Y.

regards....casey

 

[dash]

[...I don't need RSNetworx to configure & schedule the network ...]

For now, but they seem to be leaning that direction. Have you checked out the RSNetworks for EtherNET/IP? They are moving to where the newer ethernet modules for CLX act more like a master scanner. You configure the devices through RSNetworks & download the scanner image to the ethernet module.

Darren

 

[akreel]

And, your point is...??

Nothing, except that you quoted Tom's statement about not wanting to be locked into a proprietary (or brand specific) protocol. Putting ControlLogix on ethernet doesn't get around that issue.

Side question:
Can anyone cite an ethernet protocol for control that is fairly universal (accepted by a large number of devices, of different brands)? Has Modbus/IP grown up yet?

AK

 

[dash]

I would say that Modbus/TCP/UDP has more support, but with GM stating that EtherNet/IP (not TCP/IP, but as defined by ODVA) is now required for integration into new factories. I have seen more devices come out recently that support the EtherNet/IP (CIP) protocol than the Modbus/TCP.

Just my opinion (& you know what they say about opinions, especially when dealing with engineers )

Darren

 

[Peter Nachtwey]

Has Modbus/IP grown up yet?

Side question:
Can anyone cite an ethernet protocol for control that is fairly universal (accepted by a large number of devices, of different brands)? Has Modbus/IP grown up yet?
AK

No it hasn't. At best it is everyone's second choice. There are a couple issues that must be solve before anyone can consider Modbus/TCP a first line protocol:

1. Limited address space. This is a KILLER.
2. No definition for how floats and longs get passed. The smart people just make sure their products can pass floats and ints between a Modicon PLC and their product.
3. No UDP for I/O transfers. TCP is NOT the best for all types of transfers.

Our product is connected to PLCs using Ethernet/IP far more often than Modbus/TCP. We implemented Modbus/TCP because it is easy. Not because it is best.

Where did you get that picture of the sign to Boring, Oregon? Did you take it yourself?

Another question for Steve Bailey or anybody else that knows, does GE have their version of Modbus/TCP running yet? The last time we checked the GE9030 still had some basic bugs in its Modbus/TCP.

 

[RichBlunt]

I have worked on a lot of contrologix stuff, most of it is weld/body shop type equipment, but I have done two jobs that were not, and the contrologix made things easy. One was a VIN stamping application, connected to a panelview via ethernet. Ethernet IMHO is the only option, screw controlnet. The other application was a servo type deal, and again, very easy, the contrologix has built in motion instructions, and its on motion card.

I would use contrologix on anything, and especially anything where communications between processors or processors and some kind of application like RSView. The ability to make a tag, produce it on one end, and consume it on the other is just so easy.

It can be overpowered and overpriced, but if you factor in how fast you can get things straightened out and debugged. OR factor in how much maintenance time another platform may create, I think CLx will win out. I can usually walk up to a contrologix program, and within minutes know what is going on, and how it is program philosophy is working.

Hell, after doing it for so long, I just like being able to create small routines of a few rungs, instead of like two or three huge files that usually happen with other PLC5/SLC500 apps.

 

[SNK]

In our plant we have decided to go all Contrologix.
We support over 75 processors in-house, and all new equipment is spec'd with Contrologix....or Siemens....damn@@@

We currently have 6 machines using Clogix, all great. Yeah, we have to train again...but the basics are all there if you know slcs. Just add another 16bits and more cool stuff. Just try to explain the tag issue to someone that doesn't understand the difference between a word and a bit. Ethernet capabilities are far greater, and yes as is the cost.

I agree to stock spares is getting crazy for two or three platforms. I thought that we would never get rid of PLC-5's. I am now down to ONE!!

 

[awmasparky]

After working with plc2,5 and a number of slc's and a few others, I will take a clx anytime. Since I have not had any real training on any of these controllers I find that clx is very easy to pickup and start programing, communications is also much easier for me. I find clx is easier to use and I dred the times I have to get into any of the others now. We have 4 small wastewater plants in our group and I am changing to clx anytime I get the chance.

Now if I could just figure out how to do this produce and consume thing.