Modbus devices -- what do you use?

Hi OptoFans,

Which Modbus devices have you used and for what applications? Please give part numbers and serial vs. TCP, as much detail as possible. Were they easy to configure? Reliable? Something you’ll use again and/or recommend? Do share!


I use ABB VFD’s to drive the motors in our machines, preference being ACS 850 but also ACS 550. The ABB’s have an ethernet adapter module and they use Modbus TCP to communicate.

I also use National Instruments Vision Inspection software (Vision Builder for Application, aka VBAI). It allows communication with other software via Modbus TCP.

They have both been very reliable, and once I adapted the Modbus Integration kit to my needs, configuration has been fairly straightforward. I have been able to use standard ethernet switches to manage communication between the PAC controller and these and/or other ethernet controlled devices (using more customized protocols), along with PAC Display. It makes wiring and troubleshooting communications much easier than it used to be.

The Modbus TCP control of the VFD was a recent experiment, most of the machines use hardwire control. I like it, and intend to use it in future builds.

I would like to build a gas pressure manifold using valves that can be set with Modbus TCP, but haven’t spent enough time researching to see if they exist commercially.

Related to OptoMary’s question, note that Opto released the updated groov View 2.3 in 2015 that adds Modbus/TCP support. groov View can now communicate directly with Modbus/TCP devices over an Ethernet network. It’s a free update if you have a current maintenance plan.

Get the latest version of groov View at You’ll need your MyOpto login.


  • David

FYI - since our Ethernet brains have a built-in Modbus/TCP client, that means you can now also go direct from groov to, say, and SNAP-PAC-EB1 or -EB2 (no controller needed in the middle).

I just added a button that will do a hardware reset of an Ethernet brain, and of course I can read/write to my analog/digital points and even the scratch pad areas…

First post here… I’m fairly new to Opto22, but spent many years working with Bristol Babcock ACCOL based equipment. Lately I have been working on Rugid RUG9s. Just started picking up Otot22 witha new employer and I really lke it.

I don’t use Modbus yet, but am looking forward to trying to connect a controller to my water company’s master RUG9 to get the data out of it easier.

Hello SLOweather,

Welcome to the OptoForums! Thanks for posting. Are you using [I][U][B]groov[/B][/U][/I] at all?

If you’re new to Modbus + Opto, I’d recommend checking out this page: [U][B][/B][/U] especially [B][U]this Tech Note on using Modbus[/U][/B] with OptoStuff.

All our PACs act as Modbus slaves right out of the box, and if you need one to act as a master, we have options for that too. ([I]groov[/I] 2.3 will also act as a master right out of the box too.)

Of course, if you get confused at any point, there’s lots of friendly folks here on the OptoForums who are happy to help!


ABB drives with ethernet module. As [B]sensij[/B] pointed out, it’s tcp. I am trying to decide if the groov modbus would serve me better then going through the snap pac like I am currently.

Hi nickvnlr,
I bet it would just take a few minutes to set up and try… are you using the PAC for something else?
Did you see Ben’s video showing how fast it is to set up?
We’d be happy to help you get it going if you have any trouble/questions!

I checked it out and it did seem much simpler than going through the snap pac, but I have already done the work on the snap pack and I am using pac display in addition to my groov box. So, in my situation, I am not sure how useful it is yet. Can I manipulate the groov controls/modbus through pac display? If so, this may be an easier way to add additional modbus drives.

I’m not sure I completely understand your question here, but groov & PAC Display don’t really have a way of communicating w/each other. So I think you’re right, might not get you anything on this project. Keep in mind of the future, though!