Industrial Ethernet - War Ended ?

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Thread Starter

Alvin

Dear A-List Members, After few years of war, some manufacturers start to claim their product bla-bla-bla is the de-facto open standard, the terminator of all other automation fieldbuses/networks. Besides the argument that whether one single Ethernet can be the everything for all automation applications and network hierarchy, I am wondering the current status of the Industrial Ethernet: how many standards published? up to which layer? how about the acceptance of users (in US and EU)? Anybody can give me a vender-neutral overall picture of IE? Best Regards, Alvin
 
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Peter Nachtwey

1. There is no real standard. Each PLC manufacturer has its own way of communicating over Ethernet. 2. Based on our experience, the AB SLC and PLC5 Ethernet are the most popular. Ethernet/IP is a distant 3rd because it is so new. Modbus/TCP, Automation Direct are a very distant 4rd and 5th. Modbus/TCP seems to be supported by more third party manufacturers of I/O but they seem to be used mainly by soft plcs. HMI companies usually support Modbus/TCP and the Allen Bradley protcols. My company makes motion controllers that can communicate with many different PLCs and soft PLCs, and HMIs using Ethernet. We are non denominational because we support PLC5, SLC5/05, Control Logix, S7, TI505, Modbus/TCP,Omron and Automation Direct Ethernet appilcation protocols. I would say that makes us unbiased because we will do what the customers demand.
 
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> -----Original Message----- > From: Alvin [mailto:[email protected]] > Sent: Tuesday, February 27, 2001 6:06 AM > To: [email protected]-CONTROL.COM > Subject: COMM: Industrial Ethernet - War Ended ? > > ... I am wondering the current status of > the Industrial Ethernet: how many standards published? up to which > layer? how about the acceptance of users (in US and EU)? > > Anybody can give me a vender-neutral overall picture of IE? Everyone has their angle - mine is the retrofit of legacy serial devices + a bias to what I see & hear here in the USA (cannot say much about what's happening in EU). But here's my list: 1) Modbus/TCP - easy to do, probably has largest # of products available from the most vendors and will be around a long time. Unfortunately, the "owner" has decided not to add the few minor innovations required to make it a long-term world-class Industrial Ethernet protocol. It will always be a good "register poller", but don't expect it to be used for serious future distributed processing - in fact Schneider themselves have thrown their hat into the NDDS ring for this. But if you have a register-based product and plan to implement only 1 protocol, Modbus/TCP is the best first effort which will give you the largest market opportunity. You'll find it easiest to do and troubleshoot - easiest to "cut your teeth" on. 2) CIP/Ethernet/IP - complex and object oriented, but once you're past that first huge learning curve the results are pretty powerful. It's greatest strength (the "objects") is also at the moment its greatest weakness as few legacy products organize their data in such small atomic chucks as single-register or single-bit objects. Sure, the CIP protocol has "answers" for this problem - but it's just to add more complexity at the moment. It inherited a fairly ugly "encapsulation protocol" designed to solve many problems OUTSIDE the CIP world (does MORE than it needs to), but that's water under the bridge. Once you've got that into your firmware, it's just something that bugs an R&D guy who believes he could have done better himself. One strong advantage of CIP over Modbus is that it allows remote nodes to "query" and discover what data is available. Modbus/TCP still required the user to fully "config" that info coil-by-coil and register-by-register. If you're solidly in the AB/Rockwell world or DeviceNet, then Ethernet/Ip (with it's free source code at odva.org) is something to start on. If you're aiming at the wider market, then it makes a good 2nd protocol after Modbus/TCP to work on. It's my 'core' 2nd protocol on my future work. 3) FF/HSE - although touted from the early years as the "only protocol you'll need", they seem to have stepped back and now say it's a good protocol for the process industry and linking higher applications to H1 Fieldbus and linking together remote H1 buses. I agree. FF's design seems to be cleaner than CIP, but then what would you expect from something that dragged on for so long in committee verse got out and actually went to work? If you intend on linking/using FF/H1 Fieldbus, the FF/HSE is a good tool - however you'd also be wise to put in simple old Modbus/TCP for the greater mass market sales. (I see one of the strongest FF/HSE suppliers does this - instead of creating full FF objects, they just offer the key FF blocks for operations under HSE, but use Modbus/TCP as the bulk "remote configuration" protocol - no doubt this is in part because older generations of these products used Modbus. But it makes more sense to me to leave it that way) In the early days FF tried to consider how to make HSE "real-time/scheduled" like the H1 - I believe they wisely just gave up and said "HSE is Ethernet - don't expect it to do what Ethernet itself cannot do". 4) ProfiNet - still a vapor concept (the last talk I heard mentioned "open source" and "DCOM" and "OS independent" all in the same breath. I believe it will eventually come along & I'll consider supporting it as a 3rd core protocol - ProfiBus has a serious installed base. But this delay will HURT ProfiNet and allow Ethernet/IP to gain a wider following faster than it would if ProfiNet was a serious competitor. 5) GE's EGD - Ethernet Global Data. This is GE-Fanuc's "future", but so far they've shown little interest in world-domination or support by other vendors. It's a nice simple "producer/consumer" model. Check with GE if this market is important to you What else? 6) UPnP - some hope this will obsolete/kill-off all the previous, but it's advocates don't even begin to understand what a serious, safe, let's-not-kill-workers-or-million-machines industrial protocol requires. It also requires huge network traffic to accomplish what Modbus/TCP or Ethernet/IP can accomplish in perhaps 1/100th of the same volume. I believe UPnP has a wonderful role to play in management/maintenence of industrial networks - keep an eye on it, but it's got a long way to go before it can actually "control" anything with real-world consequences. Best Regards Lynn August Linse, Senior Product Application Engineer 15353 Barranca Parkway, Lantronix Inc, Irvine CA 92618 [email protected] www.lantronix.com Tel: (949)300-6337 Fax: (949)453-7132
 
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Andrew Piereder

Peter's ranking reflects my own experience, although I am getting more and more requests for Modbus TCP/IP. Andy Piereder Pinnacle IDC
 
Hi, Lynn, Thanks for your such detailed information. But I am a system integrator, not a developer. As I can conclude from your email, the war is just started, far from being ended (of course, I understand there will be no real end, like the fieldbus war). The reason we were confused is that certain Ethernet device maker claims that their product is the open standard (unfortunately they didn't even mention any standards in your list), that any other vendor who are not able to connect to their product or who are not the member of certain trade group is proprietry. It sounds that the Industrial Ethernet war has already been terminated by their technology. Best Regards, Alvin
 
PROFInet is more than a vapor concept. Go to www.profibus.com and check what will be demonstrated at Hanover Fair. "In the joint PROFIBUS booth at Hanover you will be able to see the first PROFInet-products of different manufacturers (at least 5) in a live application. You will also see the respective engineering tool, with which the engineering of the live application is realized. Experts from the different companies will be in the booth to answer all your questions on the new PROFInet standard, its advantages and application."
 
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> PROFInet is more than a vapor concept. Go to www.profibus.com and > check what will be demonstrated at Hanover Fair. You will not find any detailed engineering specs or descriptions of Profinet here however. In my view the inability of the PNO to get information out to the general public in a timely manner is a big disservice to the both Profibus and the Profibus-using general public. It is not limited to profinet either ... > "In the joint PROFIBUS booth at Hanover you will be able to see the first > PROFInet-products of different manufacturers (at least 5) in a live > application. You will also see the respective engineering tool, with which > the engineering of the live application is realized. Experts from the > different companies will be in the booth to answer all your questions on > the new PROFInet standard, its advantages and application." How many questions are we likely to have about a standard we have not seen ? Mike Davies Senior Software Engineer Eurotherm Faraday Close Durrington Worthing West Sussex BN13 3PL Tel:- 44 (0) 1903 837908 Fax:- 44 (0) 1903 837939 [email protected]
 
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