My first clx project (network help)

I am in the process of planning my first clx project and have what I think should be fairly simple questions.

I am planning on using a 1756DHRIO card. One channel will be used for RIO comm to some 1794 I/O, the other I am planning to set up as DH+ for a couple of PV 600's.

Should be fairly straight forward however I would like to tie the DH+ to our existing plant DH+ which contains a couple of PLC 5's, Slicks, programming computer etc...

My questions are are;

Will this work?
Will I be setting up the DHRIO card as a scanner or as an adapter?

I would just like to confirm that this will be a valid configuration, I can do the homework to figure out how to make it work when I get in a little deeper.

thanks in advance for the help

In a nutshell yes.

One channel can be your DH+ connection, the other your R.I/O scanner. Checkout the manual for the 1756-DHRIO module.

Bear in mind there are limits on the RIO channel, 32 rack connections and 16 Block Transfers.

I would strongly advice you to go on controlnet, You can consider gateway for interconnecting with your existing plant network

It makes sense to use one channel of the DHRIO module to tie into your plant's existing DH+ network.

If the plantwide network is running at 57.6 kb/s, then there's no problem, but if you somehow have it running at 230.4 kb/s, you need to make sure you get a Series C DHRIO module and only use Channel A.

I recommend against attempting to economize by also making this one module your I/O scanner and local HMI link. You're probably going to be disappointed with the performance of the DHRIO with two PanelViews and everything else attached. The module has a little less horsepower than the PLC-5's DH+ implementation, and wasn't meant to be the principal means of connecting to the Logix controller.

Look into using a Logix-native network like ControlNet or EtherNet/IP for your PanelViews and your I/O.

If you have an existing Remote I/O in place - use DHRIO.
If this is a new installation - try to stay away from RIO and DH+.

For HMI use Ethernet, for I/O control ControlNet or Ethernet.

For HMI use Ethernet, for I/O control ControlNet or Ethernet.

Click to expand...

I agree with this statement By Contr_Conn.
You should have 1756-ENBT in the same chassis that your
processor is in. This way you will be able to pull in the maximum
amount of data at the fastest speed into your PV.
In fact there was an article in the AB Journal a while back
showing this to be an ideal way of getting data into an HMI.

I agree, go Ethernet. you risk having a slow panelview on a DH+ network. We use a lot of control net and if I could go back I would have used Ethernet IP, but it wasent available them Control net is sometimes temperamental. In large systems you really have to manage your connections and RPI's. This may be true for ethernet IP as well.

One other thing, I would keep your I/O, panelview, drives , etc off your main control network (if you have one). Use two ENBT's in that case.

I have only one caution about Ethernet IP and it has nothing to do with the media or performance of Enet/IP but its a human issue.

Use the industrailly hardened connectors, the ones with the screw down dust cap over the RJ45 connector and industrial din rail type switches, because if your IT people see what looks like an office hub they will go ape about an unauthorized network and the next thing you know you will be inovlved in a never-ending power struggle against a bunch of boneheads who have no clue how to control a piece of equipment but who are well situated to make your life miserable.

Do I sound like I am speaking from experience?

I agree with Alaric. A factory I know are asking for industrial Enet connectors so the network does not look like ethernet to keep the IT morons out of the automation side. Regards Alan

Thanks for the advice, the reason that I decided to go with DH+ panelviews is that it is kind of a plant standard here and I already have spares for the 600, also as of right now I have no easy way of getting an ethernet drop near the processor while I can tie into the DH+ no problem (for programming). The reason I decided on RIO for the remote racks is that the number of them is limited as is the I/O and since I already had to buy the DHRIO card it seemed like the way to go. Also in the future I would like to start pulling off some of the 1771 RIO racks off of the 5's and this seemed like it would be one viable (cheap) option.


I have purchased an ENBT card for the project, I am using to talk to a Delta RMC 100 hydraulic motion controller. I would like to eventually get an ethernet drop down there and tie into the plant ethernet network but will keep seperate for now until I find out the proper way to isolate the control from the plant network (a switch I would assume) and as always I am short on time and budget.

I also had to buy a DNET card, originally I was going to use the ENBT to talk to a couple of freq drives from a certain drive manufacturer. Found out after placing the order (and too late in the project to cancel) that their drives only talk Modbus TCP, so devicenet is my only other option.

Sure hope that a spark chaser like me can make the transition from logix 5/500 to 5000 in a hurry.
I will keep everyone posted on how it goes.

p.s we only have on IT guy and he knows enough to keep the heck out of my stuff, you guys do have a valid point though