kaiser_will

PLC-5 and Omron Ethernet/IP

20 posts in this topic

This might not be workable. In my understanding, the PLC-5's implementation of EtherNet/IP is strictly an implementation of the PCCC protocol using an EtherNet/IP connection and transport set. A PLC-5 can send PLC and SLC addressed reads and writes to PLC and SLC and Logix processors. But a PLC-5 cannot directly read or write a Logix tag; addressing is always translated using the Data File Mapping feature. The PLC-5 does not support Produced/Consumed data exchange of EtherNet/IP, and it does not support EtherNet/IP I/O connections. I know that the MicroLogix 1100 can perform a CIP Generic service, and the SLC-5/05 might be able to as well, but as far as I know the PLC-5 cannot. It's been a while since I examined closely the Ethernet feature set of the PLC-5; I'd be happy to learn that I'm behind the times.

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Short answer: You are NEVER going to get this to work directly. You stand a much better chance of getting everything to work over Modbus (RS-485), DF-1 (serial or other flavor), or Modbus/TCP. PLC-5's can use explicit messaging only. And they use PCCC. SLC's are the same but they can use CSP (but I don't think they can use CIP). Micrologix does CIP or CSP but not PCCC. PLC-5's and SLC's that can communicate via "Ethernet/IP" are encapsulating PCCC (DF-1) packets inside CIP packets using a "vendor specific protocol" within the CIP protocol...in other words, loading the older protocol as a payload embedded inside CIP. Since the tag format of a CLX processor is so alien to SLC/PLC-5, the "translation tool" maps CLX tag names into the older SLC/PLC-5 tag name space. This is similar to the special mapping that is done even on SLC/PLC-5 to communicate successfully to PLC-3....it's a backwards compatibility feature. PLC-5's (and SLC's) CANNOT do producer/consumer messaging, aka "unsolicited" messages. In this mode, at a protocol level, the receiver (consumer) specifies what data it expects to receive and the transmitter (producer) automatically generates the packets at the required rate (RPI). Even IO on PLC-5's and SLC's is "passive". On a RIO network, there is always exactly one "scanner". All IO sits passively. The scanner polls all the IO in turn. It's very convenient and for the most part automatic on a SLC or PLC-5 so you don't have to worry about the details (at least for digital IO), but the requirement that the processor still does all the polling exists. For this reason, PLC-5's and SLC's simply CANNOT, WILL NOT, do Ethernet/IP based IO. And unless the Omron implements the special backwards compatibility CSP/PCCC packets over CIP mode, you stand 0.0% chance of EVER making it talk directly to a PLC-5 or a SLC, or probably even a Micrologix for that matter. If you want to still make this work, here are your options: 1. Insert a CLX processor such as the cheapest CompactLogix or similar that AB makes into the system. You're not going to use it as a CPU. Just set up the translation mapping tool and create some tags. This allows the Omron and PLC-5/SLC hardware to freely read/write the data tables as needed. 2. Use Modbus. Either write serial code on one or both sides to talk using Modbus or buy something like a Digi One IAP or several other equivalent products to act as a protocol bridge. 3. Use Modbus/TCP. For the PLC-5, you HAVE to have a protocol bridge. 4. Use DF-1. Native to the PLC-5 but you will need a protocol bridge (or code) this time on the Omron side. 5. Use discrete or analog IO's (inputs tied to outputs). Ugly but 100% compatibility at the electrical level and frequently faster than any other option, especially if you're not pushing large amounts of data. Final suggestion: just as with every other plant, start making plans to upgrade those old PLC-5's and SLC's to a CLX processor in the future.

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Thank you very much, Paul and Ken. My experience tells me that integrating anything Ethernet/IP with a PLC-5 will not be an easy chore. The suggestion of using a CompactLogix as a Gateway is probably the best solution. I have no details of the full application, as the question was posed as a conceptual one. There are a lot of PLC-5 racks in use out there, with their full replacement not having much financial merit. A Gateway approach keeps the integration simple and lower-cost (less programming covers most hardware costs). Thank you.

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Hi kaiser_will. I know this is a very old post, however did you ever get this to work? I'm trying to read data from a Allen Bradley SLC 5/04 PLC into an Omron CJ1 PLC using EthernetIP, however there doesn't seem to be an easy solution. A colleague suggested using the FINS routing table, but Allen Bradley doesn't use the FINS protocol so I'm not sure if this is possible. Any suggestion will be helpful. Thanks.

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You might find a much easier path is to use a the RedLion Controls DSP protocol converter. http://www.redlion.net/protocol-converters/dsp-series If either the PLC-5 or OMRON hardware changes in the future you will have a device that supports a multitude of protocols. Sells for around $550, great product.

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I do have code to read data from a SLC500 through a NET-ENI adapter. It is explicit Messaging based. It will read memory areas like B, I, F, but not specifically error data, unless you can get the error data into SLC500 memory. As AB does not support FINS, a common protocol like EIP is the only option. SLC500 Explicit Message 105.zip

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Thanks for your response PMCR. I will download the code, test it and let you know the results. I think B, I & F is all I need. I'm only interested in reading the machine fault code and not the PLC system faults. Thanks again!

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Thanks for the suggestion BITS N BYTES . I'll look into that protocol converter as well.

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PMCR, the document indicates that data files must be created in the SLC500 controller as N20:0 - N20:49, F21:0 - F21:49, N22:0 - N22:49 & F23:0 - F23:49. What do I do, if these data files are already being used for something else? Also, how do I read binary data? Thanks.

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The code can be modified to support different ranges in the N and F ranges. I thought I had done B, but I did not, and unfortunately I don't have a NET-ENI adapter any more to test with. The Excel file shows the File Number and Element.  For example, in reading F21, File Number 15 (HEX) is 21 Decimal.  Element Number 0 is the first register. Can you work in the N file, using higher registers, and working with bits in the N files? This is really Rockwell PCCC protocol wrapped up inside EtherNet/IP, and is much more complicated (for me) than EtherNet/IP implementations on CompactLogix / ControlLogix processors.

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I should be able to work with bits in the N file. This seems complicated (for me too) though. My preference would be to probably use CompactLogix as a gateway and then use implicit message between the Omron and the CompactLogix.  Do you have any writeup on the implicit message between CompactLogix and CJ1? I will do some research into this option. Thanks.

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That I have. The only difference between this document (written for a CJ2) is that you will use addresses instead of Tag Names for Omron, as the CJ1 does not support Tag Name communications.   CJ2 to CompactLogix Implicit Messaging Quickstart.pdf

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I did not send these postings.  I am thinking...we got spammed.

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I want to read and write the memory areas inside an OMRON - CJ2M CPU 35 PLC using Ethernet/IP protocol.

I have configured the IP address to Ethernet / IP slot, and able to ping it.

I want to know the protocol specification or request byte structure to read/write the values from/to omron PLC.

 

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This thread started about eight years ago and is specific to the integration between a PLC-5E controller from Allen-Bradley and an Omron controller.

Your question is more general regarding how Omron supports EtherNet/IP, so ideally this should be a new thread in the Omron section of the MrPLC forum.

Writing a comms protocol in any language is difficult;  some of the replies you get are going to be "buy a pre-made software toolbox", and I strongly recommend that you consider that advice carefully.

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In 2008 I configured an early application of an Omron CS1W Ethernet/IP module with a Fanuc robot controller.  Keep in mind that the Fanuc controller communicates via Ethernet/IP by reading/writing blocks of memory.  The CS1 is not the same family as your CJ2 processor, but maybe the work instruction will guide you to a similar success.

Work_Instruction_-_Omron_PLC_Ethernet-IP_With_Fanuc_Controller[1].doc

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On 7/28/2016 at 3:46 PM, kaiser_will said:

In 2008 I configured an early application of an Omron CS1W Ethernet/IP module with a Fanuc robot controller.  Keep in mind that the Fanuc controller communicates via Ethernet/IP by reading/writing blocks of memory.  The CS1 is not the same family as your CJ2 processor, but maybe the work instruction will guide you to a similar success.

Work_Instruction_-_Omron_PLC_Ethernet-IP_With_Fanuc_Controller[1].doc

Hello Kaiser,

Thanks for providing the document. But this document is more towards the commissioning part.

I wanted to know the protocol specification, telegram structure which is sent from PLC to other devices, and from other devices to PLC (Request/response). 

Is it possible for you to record / sniff the packets using some tool and provide me. That would be helpful for me.

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I do not have access to the machine.   We are an integrator and that project was commissioned 8 years ago.  Omron-US is who I would be working with.  Good luck.

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