I have about 50 industrial machines (mostly CNC controlled by a PLC). They have ethernet jacks, with an existing IP address set. I need to connect them to the main building's network (which uses an entirely different IP scheme). I have accomplished this with a few machines by installing an industrial router in the machine, and using the router's NAT to bridge the two networks. It works well, but requires a router that costs around $400, requires an electrician to install, and requires downtime on the machine.
However, each of these machines has a Samsung Galaxy Tab A8 or Samsung Active Pro tablet mounted to it, connected to the building's WiFi. I have full control over the tablets, I can root them if needed.
I am wondering if I attach an ethernet adapter to the tablet's USB-C port (I've found a few that have pass-thru charging), then plug the ethernet cable into the CNC/PLC if there is a way I can bridge the wireless connection, and also have some NAT to do the address translation and forward the needed ports.
Changing IP addresses on the machine is not an option, and altering the building's network is not an option.
I have no need for DHCP, and only a couple of devices are on the ethernet side.
Has anyone done this?
I am fully aware that wiring each machine would be ideal, but it is not feasible. To show why, I’m putting some numbers below. This application is theoretical at this point, we have a small amount of data we want to relay to an on-site server, which is then parsed and displayed on the tablets. If the testing works, we’d look into customized android powered hardware in place of the tablets.
50 machines total (at this site) $2,000 per minute downtime
30 minutes required to install cable (remove guarding and wire covers, run through tracks, replace covers)
$60,000 downtime (30 min x $2,000) $250 per cable to run $2,500 two engineers to review changes to networking and resign/recertify safety)
$62,750 / machine $3,137,500 / site
So they can spend 3 million per location and risk angry customers from downtime or they can relay some data via some android tablets.
The data is not mission critical, it is used to monitor efficiency. If there are network issues the worst that happens is the data is reported when the connection is restored.