ControlLogix MSG setup

I need some help on setting up messaging between a ControlLogix and a Thermo Scientific Hydrocarbon Analyzer. I am connected by ethernet the Protocols supported are TCP/IP, Modbus and Geysitech (Bayern-Hessen). Not sure what the last one is but it states TCP Communications. Will any of these work over ethernet to the CLX?

Thanks,

Kevin

I think it will work if the Analyzer can do CIP messaging. I'd call the Analyzer manufacturer and ask them for ideas or expamples.

TCP/IP is only a transport; the application protocol is what matters.

It is unlikely that Thermo Scientific has implemented CIP objects or Logix tags.

The easy way to approach this is to use a Modbus gateway device from RTA, Digi, GridConnect, or HMS Fieldbus.

The hardcore way to do this is to use the 1756-EWEB and explore the application protocol of the analyzer using the "Raw Sockets" feature.

I was thinking about using the EWEB module so that if I want to tie anything else in later I will not be limited to Modbus.

Thanks

The Thermo analyzer will respond to Modbus TCP message. I've done it so many times and it worked quite well.

Wow, I am looking at trying to do this next week. I have a EWEB module installed in my CLX rack. What do you use? I am currently using the streaming data protocol but all I can do is view the status string. I am very interested in knowing more about how you are doing it. I have been looking for some books on how to saet up Modbus TCP. I never remember what type of set up I need (Master or slave,Server or client). If I remember correctly I need the PLC to open the ports and request coils. This is something new for me.

Thanks for responding!

Kevin

Kev,

I've never used the EWEB module although it looks quite interesting, I may call Parijat to find out more later.

Back to our scenario, we had in the past use the Prosoft MNET module for MBTCP. Do not use the streaming protocol, just switch to Modbus in the Thermo interface, BTW the Geysitech is absolutely useless here however, it does expose more features than the standard Modbus. Put in the desired Ethernet address and it should go. The Modbus TCP implementation (to me)is 100% identical to Modbus RTU Serial in terms of querying data, one may argue the protocol transport layer is different but we will not discuss that here.

One suggestion before doing anything, download a free version of Kepware OPC Server, configure it for Modbus TCP and test it with the Thermo analyzer first. One thing to remember, in the OPC config don't forget to put in the Device ID on top of its IP address otherwise it will not work.

Once you had established comm. with the Thermo, you just simply put the ball on Parijat's court at this point. I am not familiar with the EWEB but I assume that it is similar to other Modbus TCP client tools. I would put their tech support on the phone and walk you through the rest.

We are in the process of evaluating the Brad Comm. Modbus TCP module for CLX, it is a little expensive, how much does the EWEB cost?

The Eweb was around $2500 if I remember correctly. If I understood Modbus I think I would be able to add the code but there are still some things I need to learn. Rockwell has some examples of modbus code but is as if the analyzer is opening the ports and so on (master I guess). It needs to happen the other way. And if you have any questions, tech support will tell you that they can not answer any questions about the code. Where in Ca. are you. I am a native from Ventura, Ca.? Don't tell anyone in Oregon, they don't seem to like us Ca. folks! Any interest in writing the code?

Kevin

Kevin,

Questions:
1) Are you using the 51 i series?
2) Are you more like a PLC programmer or a C programmer?

Doing Modbus comm. in the CLX has nothing to do with ladder logic know how, your mind set must be more like C proramming. From what I've seen, the Parijat seems quite nice with that special add-on instruction set, although the combined cost of the EWEB and Parijat tools are way too much money. Other than that, it doesn't look tough at all.

We had mentioned that the reason for using the EWEB is so that you can talk to something else other than Modbus, are you really? Every time you wish to do that, you are adding another level of complexity. If you already purchased the modules then we just need to move forward.

I run a compliance software company in LA and we are quite busy. Are you doing this for your company as a one time project? What did you have in mind when you asked "Any interest in writing the code?"

BTW, we are in Huntington Beach, CA.

Yes it is a 51i and I am more like a PLC programmer. We had an eweb module so I put it in the rack and played around with it for a day or so and was able to get the eweb module to open the streaming data port and I capture the stream every 30 seconds. I then decode the data and store it in the respective locations. I work for a lumber mill in Oregon as a programmer and we installed a MACT emmisions scrubber system. This is the only unit we have and we want to get better control over the FID unit. I was thinking it would be cool if there was a AOI for the ControlLogix that could be imported into the program. I have not found anyone that has an AOI for this tyoe of Modbus setup. Depending on the price we might be interested in having someone write the code. It would make it easier if who ever wrote the program knew what a 51i was. It may not matter...

The EWEB module is only connected to the FID unit.

Kevin

Kevin,

I don't think you want to pay me for this type of interface, it just doesn't seem logical. For $500 you can get a CLX component from Parijat, Texas and you should be good to go. Their component i believe is an AOI.

I will check your post to see how you progress...