Automation Direct & Rockwell Allen Bradley Communication

[ElieR]

Hello,
I have a main Rockwell Allen Bradley PLC (1756-L7) connected to a Stratix Switch (1734-US8T).
I need to implement a remote station using Automation Direct PLC to communicate with this PLC.

What is the most suitable AD PLC type and hardware needed and is there any example of communication program between the two parties?

[RBPLC]

I'm not an AB guy but I'm assuming because it's AB you'll be looking the run EIP communication on the Logix. Since you referred to the Logix as the main, I'm assuming that your AD PLC will be the Server/Adapter. Either the Productivity line or the BRX line would potentially work in this configuration. The Productivity supports Explicit and Implicit EIP but the BRX currently only supports Explicit messaging. If you're looking at doing something besides EIP, both support Modbus and custom messaging. It's likely if you're using the AD PLC as remote I/O that either could potentially work for your application. The Productivity 1k, 2k and 3k use the same programming software and the BRX is comparable in price to the 1k/2k. See links below for videos to help you decide. IMO, if you've never used either, the Productivity is easier to get going with but the BRX offers more programming horsepower but has a steeper initial learning curve. However, if you're already use to AB, the BRX is more similar with memory allocation, UDT's etc. The youtubes have quite a few videos on both platforms and cover a good portion of setup/operation for each.

https://www.youtube.com/watch?v=qqtmmN6pnzk&list=PLPdypWXY_ROraJkEd8Bvc31827BfKMc14&index=1
https://www.youtube.com/watch?v=p3K3WbX406E


 

[ElieR]

RBPLC,
thank you for the reply,
Correct I was thinking to use the Ethernet IP Communication.
While Rockwell told me they do not specify server or client in their software, I found the attached file and I am wondering if those are the correct steps to configure the  as server (Slide 3).
I am willing to send a setpoint value from the main to the AD and receive back some actual values, will the H2-DM1E be a good choice?
Thank you,
ER

[RBPLC]

Sounds like Explicit communication is acceptable so therefore the BRX should work. The second video linked shows in video form what the PowerPoint is conveying. For a new installation the H2-DM1E would not be recommended by most people. The H2-DM1E provided an updated processor for older DirectLogic hardware but uses the new DMD programming software. The BRX line (configurator linked below) is the recommended hardware for new installs. Both the BRX and H2 use the same Do-More-Designer software for programming. Depending on your I/O count the M, 10 or 18 series would probably a good starting point. The 10 series is limited to 2 I/O expansion modules where the M and 18 series can have 8 expansion modules. Coming from AB, you certainly wouldn't be accustomed to it, but the second link below is the download page for DMD software which is FREE (yeah I know, really, I just go to the download page and download it and use it?). Try out the software and see if it's something you would want to use. If you've got the Logix available you can run the DMD Simulator to make sure you understand how to set it up properly and when you get your hardware, you'll already have the programming figured out. Like I said, the only caveat would be if the Logix only runs Implicit EIP (I just don't know enough about it) then it wouldn't work. Host is currently working on Implicit EIP with other additional functionality that will hopefully be released in the not-too-distant future.

https://www.automationdirect.com/do-more/brx/config
https://support.automationdirect.com/products/domore.html

 

[ElieR]

I had a small experience with DMD v2.6 but with the H2 PLC.
Now, I have selected the BX-DM1E-36ED13 since I need 2 AO channels and additional Digital ones.

Below is the link for Rockwell reply,
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1086445

I believe the logix PLC work with explicit messaging.

But could you let me know why you concluded that explicit is enough knowing that those shared variables should be real time updated.

[BobO]

I had a small experience with DMD v2.6 but with the H2 PLC.
Now, I have selected the BX-DM1E-36ED13 since I need 2 AO channels and additional Digital ones.

Below is the link for Rockwell reply,
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1086445

I believe the logix PLC work with explicit messaging.

But could you let me know why you concluded that explicit is enough knowing that those shared variables should be real time updated.

Define "real time". The EIP client/server functions in Do-more are pretty fast, but implicit is usually faster.

[ElieR]

BoBO,
I meant by "real time": continuously being updated since they are operation variables and not configuration ones.
we don't need extremely fast communication which I believe this is what you considered in implicit.

[BobO]

BoBO,
I meant by "real time": continuously being updated since they are operation variables and not configuration ones.
we don't need extremely fast communication which I believe this is what you considered in implicit.

I just did quick test, have a BRX read from its onboard EIP server as fast as possible. It's running 185 transactions per second.

[ATU]

If update time is a top priority, there are tricks that you can do.  Much of it depends on what else is going on in the Logix processor. Use the native port on the CPU if you have one. You can also do multiple simultaneous MSG instructions. The CPU will buffer them and they will execute faster than using one on alternate scans. Also there is a CONNECTION checkbox in the communication's tab. Check that box and it will maintain a connection with the BRX. That way it doesn't close the connection after each transfer. The BRX EIP server does an excellent job. I have it collecting data in several installations from Compact Logix and Control Logix PLC's .  I have more trouble with the AB side than the BRX, so you have to monitor for an ERROR on the AB side and restart the instruction.

Here is a document you need to download.

 https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwj3k8ah073oAhXCnOAKHc8RAPcQFjAAegQIARAB&url=https%3A%2F%2Fliterature.rockwellautomation.com%2Fidc%2Fgroups%2Fliterature%2Fdocuments%2Fpm%2F1756-pm012_-en-p.pdf&usg=AOvVaw0UAxFrBITvx3KVlzXKAGWE

[RBPLC]

RBPLC,
thank you for the reply,
Correct I was thinking to use the Ethernet IP Communication.
While Rockwell told me they do not specify server or client in their software, I found the attached file and I am wondering if those are the correct steps to configure the  as server (Slide 3).
I am willing to send a setpoint value from the main to the AD and receive back some actual values, will the H2-DM1E be a good choice?
Thank you,
ER

I took "willing to send a setpoint" to mean that your process wasn't very fast and assumed that Explicit would be plenty fast enough. I don't have extensive experience with EIP but the distinction between the two usually becomes a bigger issue when trying to coordinate motion which does require high speed comms. I believe what you're describing can be done with EIP, Modbus, custom etc. If we were really talking about high speed and performance, the discussion wouldn't be about EIP anyway it would be about EtherCAT.

[ElieR]

The hardware that will be used from the Logix side is:
1756-L71S (PLC)
1756-EN2TR (Ethernet/IP Card to communicate with 2 Power Flex drives & 1 HMI ),

[DLTimmons]

Forget Modbus Ab does not use it. You have to get a ProSoft third party card and they over lap all data types. Coil 1 is bit 1 of resister 1 and input coil 1 and bit 1 of input register 1. A real Pain!

[Bolt]

I feel bad posting this here, as I think the BRX is a GREAT PLC.  But others have mentioned Productivity units, so I'll throw the CLICK out there.

https://www.youtube.com/watch?v=fcWbGf73ldc

[Controls Guy]

Forget Modbus Ab does not use it.

Not natively, but there is an AOI available to do Modbus/TCP iirc.  Plus the Prosoft modules aren't really bad, I've done the older PLC/SLC versions quite a few times.

[DLTimmons]

I was working with a compact logix. the prosoft worked you had to do a lot of work to make sure that your modbus data was addressed in different area of the prosoft memory.  This was a large system with 2 PC's, 5 Domores , 5 click's, 20 VFD (Modbus was the only option on the drives)  all communicating with each other. The PC tied back to a server running the plant operation software. This was before domore could do EIP.