Using non-standard Ethernet modules with ControlLogix

Hi,

I want to try and use a Ethernet device in my RSlogix 5000 program. As far as I know, no-one has ever used it with a PLC.

The device is a programmable serial to Ethernet converter and has a configurable ip address with software that can be used to change settings and such. It would generally be used in a PC but I'm trying to give it a shot with a PLC.

I've worked with Ethernet/IP modules before, the only thing is that this module/device has 5 ports in (serial) and 1 ethernet port out. I need to be able to read data from each serial device separately. The device it self has pre-assigned port numbers so I can call to receive information from any of the 5 ports.

Normally I would just use a comtrl DeviceMaster or RedLion product, but I'm trying out something different.

Has anyone done something similar?

The Ethernet - serial adapters are designed to create remote serial ports for a computer. The computer would need the software to read the serial port and 'translate' data from it to usable data.

I don't think a PLC would be able to read the data off a device connected as such, if it does see it. It would have to message the device through its serial interface and the data would have to be in an addressable number or bit.

This may be able to do with a PC HMI reading the data and with a DataSubsciber (AdvancedHMI label) relay it to a PLC.

Thank you Aabeck,

This project is a little out of my comfort zone, I generally don't have to deal with weird networking problems like this so forgive me if I sound naive!

Your first sentence it what has worried me the most, being able to actually read the data from the devices when it reaches the PLC. The device has its own software client that would be used on a PC. When I talked to the manufacture they made it sound like you could configure the data output through the converter itself BEFORE sending it to the PLC. I have yet to confirm how that is actually done, i'll probably have to give them another call.

I was hoping I might be able to get around having to send data to the actual serial devices since I don't think I really need to.

The serial devices will automatically send data (Raw ASCII) to the serial>Ethernet converter whenever there is new data to be sent.

The converter will just need to send that data to my PLC so I can record it and maybe find some averages and such. So I'll have the known ip address for the converter. I just need to know which port on the converter corresponds to which serial device.

Honestly, now that I think of it, it almost doesn't even matter if I can or can't differentiate between each device as long as I can reliably get all the data. I would be getting the average from all 5 devices anyways.

Probably could use UDP messaging, I've used it to interact with non-supported devices over Ethernet, RSLogix 500 and 5000. Search the RA Knowledge base, there are a number of different examples offered.

As far as I know, no-one has ever used it with a PLC.

Click to expand...

In my experience, the cost of labor to figure out how to connect a device that is not designed to work with PLCs is far in excess of the differential to buy a Red Lion, *******, HMS, RTA, Digi, Prosoft, or similar device.

While you can theoretically do a lot of stuff with the Raw Sockets feature in Logix 5000, it's a lot of work.

Start by posting the exact vendor and part number of the device, and what Logix 5000 family controller and Ethernet interface module you are using.

Ken Roach said:

Red Lion, *******, HMS,

Click to expand...

They're still not liked here I see.

Interesting... I was referring to the maker of the DeviceMaster.

If the multi-port device accepts incoming serial data and buffers it until you send it a specific read command on a specific TCP port, it might be reasonable to spend the time on the raw sockets software.

My prerequisite remains: Post details on the devices.

If you need a bunch of serial ports in a Logix just use a Point block and use the ASCII modules. They are real easy to use.

Normally those things have a socket server running on them. You should be able to use raw sockets to talk to it.

Jax, I was a big fan of those 1734-ASC modules until the uncovered a low-level conflict between their large-block data transfer and the POINTBus.

IAB will now warn you not to use more than three per adapter. That's fine for most users, but not if you have a large number of ASCII ports.

Red Lion DataStation Plus (or the new DataStations) are my go-to device because of their flexibility and longevity, but there's a lot to be said for the ease-of-use of an RTA gateway, or the widespread popularity of an HMS Communicator.

Thanks for the responses.

I'm using a ICPDAS I-7188E8D. It's a programmable 7 port serial to ethernet converter. The problem with just using point to point that there would be A LOT of wires and PLC cards needed when it is all send and done.

Currently I just have a regular AB 1734-AENT card. I can get something different though. Rockwell mentioned using the open socket feature could possibly work.

Correction,

I have a 1756-L81E controller with a 1756-EN2T ethernet card available.

Ken Roach said:

Jax, I was a big fan of those 1734-ASC modules until the uncovered a low-level conflict between their large-block data transfer and the POINTBus.

IAB will now warn you not to use more than three per adapter. That's fine for most users, but not if you have a large number of ASCII ports.

Red Lion DataStation Plus (or the new DataStations) are my go-to device because of their flexibility and longevity, but there's a lot to be said for the ease-of-use of an RTA gateway, or the widespread popularity of an HMS Communicator.

Click to expand...

That's good to know, thanks.

ICP-DAS sells a lot of very interesting stuff, but their Chinese translations and "it's programmable and can do anything !" approach frequently boils down to "we sold it to your customer, now it's YOUR problem !".

The selectable transmit feature seems straightforward, but at first blush a selectable receive looks like it would be difficult to implement with raw sockets. It's really designed to run the virtual COM port function.

JaxGTO said:

If you need a bunch of serial ports in a Logix just use a Point block and use the ASCII modules. They are real easy to use.

Click to expand...

I used these before also. They work great. This seems like a good consideration for the project. The Controllogix has a good instruction set for ascii data.