Networking Legacy Allen Bradley Devices

3 posts in this topic


In a certain area of our facility we have several machine that manufacture a handful of products. These machines were built at random intervals starting in the late 80's and consequently have a range of different PLCs that are used to control them (SLC 500 to ControlLogix L61).


The other areas of our facility use a server that has a historian installed (Canary) and the client (Axiom) is installed on our computer so we can view data trends in real time.


 I would like to network our PLCs mentioned in the first paragraph to this historian to gather production and maintenance data.


I know that I need to network these devices through an OPC server (which we have).


Several of these devices have been connected through DH+ and/or Ethernet networks in the past but are no longer connected.


We recently connected some of the DH+ Devices to the Ethernet network (just to see if we could) with a Prosoft AN-X2-AB-DHRIO.


My questions are:


  1. Are there any best practices for networking devices with different protocols, i.e. DH+, Ethernet, etc.?
  2. Is the way we have it set up now (with the Prosoft DH+ to Ethernet bridge) a robust (scalable, etc.) solution?
    1. Is there a better way to do this?
  3. Is it worth getting EtherNet/IP cards for the PLCs that don't have them?


If anyone has any experience with a similar scenario, insights/advice would be much appreciated

Share this post

Link to post
Share on other sites

For capturing manufacturing data, utilize the hardware you have.  Legacy processors often support DH+ networking.  However, DH+ networking tools are not plentiful but do exist (Ethernet/IP networking tools...a patch cable and a PC).

What is your project budget?  If there is no budget or you have to keep costs down, utilize the hardware you have.

Implemented a similar solution some years ago...islands of machines with PLCs, nothing talking together; networked processors via DH+ back to a networking bridge Logix PLC that hung off of an Ethernet network.  DH+ Networking lessons learned is attached (there are some gotchas).

First...start small.  Get the network up and running with 1 machine.  Verify.  Expand the solution.

Second...what data should be archived, archive duration, backup data archives, datapoint duration (Delta-T - the time span between datapoints), have you calculated hard drive space needed, when will the data archives max out the drive capacity.  Often, managers want the data when there is a problem but may have no interest when all is well.  The DH+ network I built was a tool designed for Maintenance Techs to quickly connect, access correct program archives, access troubleshooting materials.

DH+ Networking.doc

Share this post

Link to post
Share on other sites

This is awesome. Thank you for sharing. HUGE help.

1 person likes this

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now