1756-DHRIO 'Routing Table' to Ethernet ?

I have a customer that has a older system has several 5/04's using DH+ to older HMI (s) on a DH+ network

I am not sure of the exact configuration as far as how many nodes but they are looking at changing their 5/04's to 5/05's the issue is they can not replace the HMI nor can they get into the code.

So to save money and not reverse engineer the HMI and rewrite the code their thought was to use a 1756-DHRIO and ENBT as they were told by AB's tech support that they could set up a 'routing table' on one of the channels

I have used a few DH+ to Ethernet bridges in the past but never used the routing tables, looking over the manuals ( 3-2 http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um514_-en-p.pdf ) not sure if this is what they are looking for... I see a lot of messaging but I don't think this is a message, its more of a pass-threw

Would this work?

Thanks for your help!

Bump... anyone, even a WAG would be nice

I'm not 100% sure but I don't think this would work. From my recollection, the routing table in the DHRIO is used for identifying different networks and assigning them link IDs to allow MSG instructions to flow through the different network architectures. I'd have to think that at a minimum some sort of channel configuration in the HMI's would have to be done, unless it's using a DDE/OPC server like RSLinx.

Like I said though, I'm not sure and will be the first one to admit that I'm way off here.

Not a Portal to Narnia

When you browse a DH+ network, the addresses you see (0-77 Octal) are the Local Station Addresses.

But the DH+ protocol also includes in every packet a Remote Station Address, a Remote Link ID, and a bit switch to designate the packet as a Local or Remote message.

In the old days, this allowed you to link DH+ networks together and send a message from a PLC on one DH+ to a PLC on a different DH+ by designating the whole path from the local network, through the linking device, to the remote network. RSLinx Classic is particularly adept at sniffing out those links and browsing through them.

The Routing Tables in the 1756-DHRIO do the same thing but instead of having a DH+/DH+ link device, they can make any CIP route over ControlNet or EtherNet/IP or the ControlLogix backplane into a Link. Think of it as a hyperspace jump from one DH+ to another, rather than a little footbridge.

From the perspective of a PLC or HMI or computer on a DH+ network, the 1756-DHRIO and whatever is behind it looks exactly like an old-fashioned DH+ remote link. That means that the PLC or HMI or computer needs to fashion its packets to include not just the Local Station Address but also the Remote Link ID, the Remote Station Address, and the Local/Remote flag.

Because your HMI is on a local DH+ network, it's almost certainly sending locally-addressed DH+ messages. If you cannot modify or reconfigure it, you cannot change it to send remote-addressed DH+ messages (if it even supports them).

The question, then, is "can I configure the 1756-DHRIO so that a local DH+ message to one if its channels gets sent directly to an SLC-5/05".

Unfortunately for your application, no.

What Rockwell chose to do with the 1756-DHRIO was to take Local DH+ messages and route them to a backplane slot (the default was Slot 0).

This allows you to install a ControlLogix CPU in Slot 0 and have it respond directly to DH+ messages that were pointed at a local DH+ node (like a PLC-2/3/5).

If you were replacing the SLC-5/04 controllers with ControlLogix, the HMI on DH+ would work, unmodified.

There may be third-party devices that allow a "1:1" translation between Local DH+ and Ethernet, but I'm not familiar with them.

Thank you all very much, this will truly save my customer some time and money

Thanks again!

The Plc Kid said:

http://prosoft-technology.com/proso...e_gateways/ethernet/ethernet_ip/an_x_ab_dhrio

Click to expand...

I used the ANX DHRIO recently and highly recommend its use.Very easy to configure and worked like a champ.

So that's two recommendations for the AN-X, but they are presented without commentary about whether the device is appropriate for this specific application.

I'm a big fan of the QTS-built modules and have used other models (the RIO and GEnius) successfully.

Here's the question: Does the AN-X-DHP have a "routing table" or "1:1" feature that will allow it to forward an incoming local DH+ message to a single EtherNet/IP device ?

I don't think that the Prosoft solution will work. It's an Ethernet TO DH+, and like Ken said, you need a DH+ TO Ethernet.

The Prosoft card works in both directions. The AX_X shows up as an Controllogix rack on Ethernet. I am not sure about the routing. My app was a ABB robot on RIO to a Compactlogix L32E.
Link to user manual.
http://prosoft-technology.com/proso...e_gateways/ethernet/ethernet_ip/an_x_ab_dhrio