E14 Community recommendation for ModBus TCP client

Screen is touch, that is about the extent of my knowledge.

It has network capabilities but we currently are not using it. The objective is to extract the scale data and move it to our ERP system.

oh its an embeded linux web server with IO!
maybe ill see one cheap on ebay and really have at the thing
at 4K$ new, ain no way.

I'll necro post.
pymodbus tcp typically does fine.
My boss showed me another library recently that seems to work well... bu t I forgot what it is called.
typicaly, I start with a register map, then build out functions from there. dealing with modbus kinda sucks.
I typicaly build lists, or arrays, while my co-workers seem to like json files. thats a design choice, I favor application development, 
where they favor web development, though either could work. 

A specific application? lol IDK about that, I would just write it. 

out of curiosity, its that a touch screen? is button IO writable?
can you push (load) different screens remotely?
what is the display graphics programed in?
are there other interfaces for programing the display?

Sorry folks I am not necroposting. I recently found a Modbus resource tool that would have been ideal in this project. Command line console for modbus. I can try and remember it for the next time or put it in a place I do remember. 

https://github.com/utilsec/Modbus-Swiss-Army-Knife

The name of the link should tell it all. I tried it with my scale project and discovered that via packet sniffing, it does a lot of communication when it first fires up.

If the end point is missing (i.e. typed in wrong IP) the software doesn't start. If there is a modbus device a text screen appears.

I will close this post by first saying thank you for your input. Sounding out the problem and getting suggestions was helpful in arriving at the solution.

I culled a link for oceancontrol windows GUI client from the link  beacon_dave provided.   shabaz python client established a connection, I just didn't invest in generating a query. It did confirm it was working. BigG  input reminded me of net cat a network test tool I had used many moon ago. I confess net cat was the one I used the most.

Since I was only looking to confirm a connection through the firewall, net cats ease of use made it ideal for quick testing. Supported on windows and linux was bonus. I had to learn the syntax for Windows:( It is not the same as linux.

With a confirmed modbus tcp interface available it is off to configure and test a VPN end to end solution that will connect the company and vendor. Thanks again for you input. 

Ah fantastic. Not that I would know (noob here). Apparently with netcat, you can transmit the structured Modbus application bytes and see if the hardware replies. This completely validates both the firewall rules and the device's availability in one go.

Searching online brought up this page: stackoverflow.com/.../send-modbus-rtu-request-via-tcp-with-netcat-and-catch-the-response

I completely forgot about CLI netcat! I recall you can setup a transmit and receiving end on ports you are examining.

Man I miss tech coffee breaks. All those minds in one place was a great technical pool of knowledge.

I cannot take the credit, AI wrote that code, I merely pointed it at the 1280 user manual, and it spit out Python code, I merely ran it and told it of any errors, so it could correct it. The screenshot below shows what I asked it originally. It's not perfect as you noticed, since it could have provided more helpful output or automatically abort a test rather than hang.

Regarding the TCP connection etc., I'm very familiar with that part only because I ended up developing some products that heavily relied on network features/functions, I believe I would struggle with a lot of it if I had to learn it on my own.

I'm humbled by your knowledge and thankful that you are willing to share.

Many eons ago, when my skins had less wrinkles, I recall training with a senior aviation electronics technician in a course. He took the the time to share his experience. The stuff I learned in that short interaction I have never forgot. 

I can't comprehend how you extracted the information from the manual that enabled you to write code and decode the output for the modbus tcp interface. I'm envious.

I recall listening to a lecturer speaking Russian. I figured if I listened hard enough I would understand Russian. Never understood a word! I have combed the manual and reviewed your code thinking if I try hard enough I will gain the knowledge. It is not working.

If I was forty years younger, I would invest the time. I accomplished the goal. Just have the test the firewall rules set and be done. Thanks again.

I tried you trick of connecting to an IP that didn't support modbus tcp and noted the error. I suspected your code was working. Great work on a first attempt.

I believe the video is where I found the bread crumbs to the site.