I once built up a demo project for client that wanted to use use a 40" screen to display advertisements to people trapped in their car when in a car wash (one of the car washes where the car is stationary and the spray heads rotate around it)
My idea was a small Linux based computer running a web server displaying to a full screen browser to which the monitor connected via HDMI. The computer would then connect to carwash PLC via parallel digital inputs. But being a full blown computer I could have easily connected via Modbus/TCP
I only went as far as a getting the demo running before they scrapped the project, but I did source reasonably priced 40" monitors that could run inside a car wash and operate from -30F to +120F, and also some matching computers that could run in the same environment and had 8 suitable digital inputs.