Communicate with off-site machinery - suggestions


so I'm working with an OEM, who would like to start renting out machines. In turn they would like to be able to monitor them remotely. Run time, product count, etc...

I'd like to set them up with an Vision screen to monitor stats for each machine, allow access to write to the plc if need be, and even access it in the case of troubleshooting.

What would be the best away to accomplish this, as I don't know where the machines will be placed.

Would cellular modems cover connectivity needs?


I may need two methods. I thought cellular would be a good option, but I can't guarantee signal available.

But I'm not super familiar with them, how do I buy a plan for them? How do I connect? can it act as comms for igntion and if I want into the plc?

I looked into some cellular modem and satellite options a few years back for mobile plants, but we ended up continuing to work with clients to connect via their networks in one form or another instead as our equipment was pretty consistently connected to customer networks.

Short version is yes, cellular modems can give you the connectivity you want (where wireless service is available). Connection will likely be via some sort of VPN. Others on here have made extensive use of them and shared more details. Some posts that may be helpful:

If you can't get wired or cellular connectivity, would something like StarLink mobile work (assuming your equipment is above ground)? It looks like it should soon provide global coverage with a single system at a reasonable per unit cost (much more affordable than anything I could find to cover our equipment on some continents when looking into satellite options years ago).

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I think both are viable. I will have to talk more with the OEM about their customers. I think cellular might be best.

I don't want them to rely on the customers infrastructure for rented equipment. Like I don't want a customer to be able to lock them out cause we go through their network.

I'll still have to learn more about the cellular networks and connectivity with them.

I do the very thing you are describing, albeit the equipment is ours and we don't rent it out, we use it on our own projects.

I've gone through many iterations to get to where we are now. Started out with raspberry Pi's and nod red for local access via the inbuilt dashboard. VPN was over hamachi, connectivity either via local wifi or cell using twillo sim cards.

As the the machines grew and got more complex to meet our customers depends we needed a better HMI then what node red could offer. I tried many devices and they worked but it was just a little clunky.

All the data was being sent over MQTT back to our main ignition server so we could see what the machines were upto and send messages back if we wanted to change a set point or something. I still needed to solve the issue of having a better HMI for the machine but remain portable and easy to scale across all our portable machines. I wanted the HMI to be in tablet form and not a fixed hmi, which would have been easy as all our machines use siemens plc's and parts etc and the larger static machines use siemens HMI's. But on the smaller portable machines there isn't and real estate for a 15" HMI.

In the end I weighed up the costs and tried out edge. I originally stayed away from this route due to costs, a PI and node red at the time was 40-50$, now a pi will set you back 100-200$ if you can find stock. A edge license can be 1-2k depending on what licenses you need, across 30-40 machines that's expensive. The intermediate HMI solutions i tried like maple systems servers etc were 500-700 depending on spec. So I wasn't far off the edge costs so decided if we are going to do it, may as well do it properly.

So our final solution is edge, hosted on a PI, amazon firetablet with perspective side loaded for local access and a wifi / cell modem with fail over which includes VPN (Stridelinx). The machines send the data back using MQTT transmission on edge to our main ignition server. Local access is using the firetablet with edge set to perspective, I can also VPN in and load up the hmi remotely.
Edge only allows one project so to make it easier I used EAM. I have one project that covers all the machines, so all the screens for all the machines are in folders to keep it organized, when the user connects to the machine (the stridelinx vpn also has a hotspot mode) and opens perspective it looks at a OPC value in the PLC to determine what type it is then loads up the appropriate home screen. So that project is developed on our main ignition server then pushed out to the edge devices via EAM. Data comes from the PLC's via OPC so designing the screens on the main ignition server is a little tricky as all my created OPC values are faulted. I tried to keep some what of a standardized list of OPC values across the machines, so value 1 is serial number, value 2 is machine type, etc etc.

So far it has worked well, and realized that with EAM you can move licenses around. So say we have 40 machines but really only 10-20 are used at a time I can swap licenses around to keep initial costs down. Good thing is you can set all this up in trial mode to test it out before spending a cent, well apart form the hardware.


@craigb the machines have mostly Delta HMIs, and Delta PLCs.

I just need a dashboard for the OEM to monitor stats, uptime etc.... A VPN so I can access when people are having trouble.

MQTT might be viable for data to Ignition. What are the cost related to MQTT i'm not familiar with it, but hear a lot about it.

I'm not familiar with the Delta PLC's, quick google search shows they use modbus.

Assuming you already have a ignition server, it would be about 4k to add MQTT (Engine and Distributor). Don't quote me on that though.

You could use something like this

This will talk to the delta plc and give you MQTT out the box. Couple that with a cell/wifi modem / router and your good to go.