I have an Allen Bradley SLC-5/03 PLC inside a few machines. i want to turn these PLC racks into remote bases that are controlled by a 1756-L55 5000 series Control Logix. I am currently using profibus to control a number of other bases so I was tring to find out if there is some kind of remote base card that can replace the PLC that uses profibus?

Any ideas?

All the Profibus cards I've ever seen for the 1746 (SLC) platform are scanners, not adapters, so you can't do specifically what you describe.

The principal way to connect 1746 I/O to ControlLogix is to use the 1747-ASB adapter in the SLC racks, and use the 1756-DHRIO scanner on the ControlLogix side.

The 1747-ACNR15 cannot connect to ControlLogix over ControlNet, and there is no 1746 adapter for EtherNet/IP.

This might work, but you would need to keep the 5/03 proceesors too:

http://www.prosoft-technology.com/prosoft/.../slc/mvi46_pdps

Thanks for the quick reply. I have considered that. I am using the Prosoft module to communicate to some old 505 Racks.

The primary reason i am doing this is for consolidation. I dont want a bunch of 500 series PLC's around if i can run everything off of essentially one 5000.

Is there another communication method i should be looking into? I like profibus and I use it for just about everything.




Does the 1747-ASB adapter use DataHighway?

No, it uses the same wire (Blue Hose) but Remote I/O protocol and DH+ protocol are different.
The 1747-ASB is Remote I/O

Why don't you go to Eathernet i/p for you new remote i/o and then bridge profibus on the same rack you have your plc in.

I have purchased these cards to try and get communication via Remote IO. Has anyone ever actually done this? There is 24 dip switches on the 1747 Rack, half of which i am not sure what the purpose is. Which is probably the reason i cant get it to work.

Who has had success with these?

The 1747-ASB was introduced 15+ years ago, so it is a well-understood and successful product, so the short answer is "yes, many users have success with these".

In order to know how to set up the DIP switches and how to configure the 1756-DHRIO scanner, I'd have to have an inventory of your I/O modules and know more about the scope of the network (how many chassis, how far they are from each other, etc).

Start with the user manual for the 1747-ASB adapter, publication 1747-UM006, and the Installation Instructions for that module.

http://literature.rockwellautomation.com/i...um006_-en-p.pdf

http://literature.rockwellautomation.com/i...in014_-en-p.pdf

I generally try to set things up for "1-rack" addressing, where each Logical Group is one physical slot that has 1 word of Input data and 1 word of Output data associated with it.

OK, well after some fiddling around with group numbers and sizes and stuff I got this thing to communicate. I even got the 5000 series PLC to read and write to the rack.


However I have one major problem. After a few minutes or so the communication will drop and the 1747-ASB will read "noc". and the scanner stops functioning. Also, if i am connect to the PLC when this happens my connection locks up until i pull the scanner card out of the rack.

What could be causing this? It must be some kind of configuration or something no?

It sounds more like an installation problem to me; "noc" just means "no communication" and indicates the 1756-DHRIO has stopped exchanging data with the 1747-ASB.

But... are you connected to the DH+ port at the same time you are scanning the RIO port ? MSG programming issues might be able to overwhelm the DHRIO module and "kick you off" the module.

Can you describe or post the logic you are using the send Block Transfers to the 1747-ASB ?

I am not using Data Highway and I not connected to the card at all. I am configuring it by using the eithernet module in the rack and configuring it using rslogix5000.

Its just odd that it loses connection and completely locks up the PLC. I am fairly certain its not a cabling issue because when i manually remove the connector and reconnect it it regains connection. The 1747-ASB says "run" on it when it is running. and everytime to get it back to communicating i need to pop the scanner out and pop it back in and then it works for another few minutes.

Well, we're getting into a different sort of issue, here, one that might be better pursued with ordinary RA Tech Support.

Does the controller actually fault, or do you just "get kicked offline" and cannot re-establish a connection to the controller ?

I have three guesses on what's going on:

1. The block transfer logic you've implemented is overloading the controller's communication buffers, leaving the controller unable to communicate with anything, including the Ethernet module and your RSLogix 5000 station.

2. One of the modules, probably the 1756-DHRIO module, is damaged or defective. If you're not familiar with the "Atmel backplane chip issue", you might have to physically inventory your modules to be sure they're not affected.

3. There's a very strong noise signal coming in through one of the communication ports and interfering with the controller's backplane connection.


My first diagnostic would be to disable the messaging logic that sends block transfers to and from the module, and see if the communications failure happens.

To diagnose the block transfer logic, I would need an inventory of the modules in the 1746 rack and a copy of that logic.

Is there a reason i should have block transfer logic? I have communication with the IO tags without any kind of block transfer logic. I dont have anything programmed to the RIO addresses yet.

There are no atmel parts in this card. I am not sure what else to check for with respect to that.

Could it have something to do with the cabling? Maybe the resistor size? i really doubt it but i figured i would ask. I am just using 100 ohm resistors on both ends.

I think you might be on to something here.

This is what i found in the knowledgebase:


http://rockwellautomation.custhelp.com/cgi...040&p_olh=0