Free Modbus Driver in .Net

S

Stephen McLain

Hey there. I'm the original author of this thread. I'll go ahead and provide an update.

After posting this and following the advice of the members here, I continued to search for a free solution out there, but I never made any progress. I ended up walking away from the project. I'm now managing the department I was working in at the time of this posting.

We're still facing a situation that threatens to make our HMI software obsolete. We did, and currently still do, utilize Modicon Momentum PLCs that communicate across Ethernet. The HMI we use is National Instruments' Lookout, version 5.1. Lookout has been nearly abandoned by NI in favor of their Labview product. This version of the Lookout software does not work with Windows Vista, 7, or 8 and is becoming obsolete.

Newer versions of Lookout have managed to come out, but the upgrade expense is very high--I'd have to buy all new licenses. I also simply wished to have more control over my HMI design and was, therefore, most inspired to pursue my own development path.

We are an OEM company with multiple deployed units (and therefore licenses). The cost of purchasing a new license for each system adds up to be rather prohibitive. This led me to search out an open source or free option.

Many of the solutions proposed within this thread were very promising, and I've revisited them. However, they've remained untouched for quite sometime now (MBLogic for instance), or they're dead ends that just lead to paid options (nmodbus and kepware). The open source projects were intriguing, but I really didn't want to assume work on an HMI solution that has already been tailored by its developer for his or her specific needs and subsequently left to die.

My major hang-up is that I think it should be so easy. All I should need is to reference a dll, have documentation to call its methods, and off we go.

Right now, I'm trying to figure out if FreeModbus on SourceForge is what I'm looking for. It's current, and as of this writing was last updated 15 hours ago.

So, that's where I'm at. Can I offer any kind of solid advice or breakthrough wisdom to solve your problems? Not yet. If I ever do, though, I'll be sure to post about it here...in detail, so you guys have real instructions that you can use.

Hope you're all doing well. And, if your issues have come to resolution, please, let us know about it!
 
Just seeing if you have an update. I need a .NET control for an SLC500 through TCP/IP. I am looking at the pay-for solution from AutomatedSolutions, but the licensing is so crappy. I can't even get a custom build working with the demo because they lock it off. Anything with that level of license verification will never be used in my code. I need it to always work, not just work when it feels like it is licensed.

If nobody has done it yet, I guess I will have to roll my own. It is surprising nobody has a high level driver for these things.
 
Hello,

Automated Solutions trial software is not restricted in any way. It is fully functioning for 30 days.

If you are experiencing problems just contact Technical Support by phone or email. Trial Edition tech support is free and available M-F 8-6 PST.

When you build your project after purchasing a development license, runtime licenses are built into your executing assembly and work 100% of the time. Standard MS component licensing is used and we have not had an issue for 20 years.

For the trial edition, the only thing you need to do to deploy to another PC is to run the trial edition setup program on the runtime PCs. Your applications built with the trial edition will run for thirty days. Again, this additional step is not required after you purchase a development license.

-Mark
http://automatedsolutions.com
 
I wrote a simple Modbus RTU dll for use with .NET. All function codes are there and there is also simple functions for conversions such as bit packing and short to float. I know that you're looking for Modbus TCP/IP but maybe someone else can use this.

It is available for download here:
http://sites.google.com/site/shortbusdll
 
My dll ShortBus provides Modbus master functionality for RTU and TCP/IP, as well as slave simulation for RTU. It is easy to use and has good documentation. Compiled versions are available for .NET 3.5, 4.0 and 4.5. CE versions for 2.0 and 3.5 are available but don't have the TCP/IP functionality at this time. I also have a free master scanner tool (comparable to ModScan) that reads from RTU and TCP/IP slaves.

It is available for download here:
http://sites.google.com/site/shortbusdll
 
M

Matt Gristwood

Hi.

I know it's a long time since anyone replied to this post but figured I would try and help. Have you looked into AdvancedHMI? This is completely free built in Visual Basic and has wonderful support. Go to AdvancedHMI.com and check it out.
 
> My dll ShortBus provides Modbus master functionality for
> RTU and TCP/IP, as well as slave simulation for RTU. It is

I downloaded it and it looks very nice. Very professional documentation, not something that you see all that often.

I was concerned about the lack of licensing terms, I understand that it's freeware, so I would assume that includes its inclusion in for-profit programs is permitted?

>It is available for download here:
>http://sites.google.com/site/shortbusdll

Your links on the left are broken, to download your packages I had to click on the ones to the right.

Thanks for the programs, I've got a few abandoned Schneider PM's here at the house to try it on. :)
 
The link issue is with Google Sites, since the right links work I won't worry about it.

As far as licensing goes, it is free to use as desired (but the source code is not provided).

> Your links on the left are broken, to download your packages I had to click on the ones to the right.

> Thanks for the programs, I've got a few abandoned Schneider PM's here at the house to try it on. :)
 
Hi there,
I've sent you a couple of emails regarding shortbus.

Is it possible to change the starting address from 40001 to 0?

Please get in touch :)

Thank you

Regards
Darren
 
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