I'm building a network of controllers for big building and I want to use 4 SBC66EC boards to exchange information over Ethernet. I'm doing this because there are already Ethernet cables running all across the building back to a router.
I have each board reading a cluster of sensors and controlling a cluster of actuators. This is quite straight forward.
Now I want to control all 4 boards through 1 board. The master board will send my inputs and a few sensor data to the other 3 boards and they will send the sensor readings and status of the actuators back to the master to display on a webpage.
I tried to implement this by getting the boards to send webserver HTTP commands with Java script then I realised they will not communicate if the webpages are not open.
Can someone please guide me in the right direction to set up the communication using Ethernet? What protocol shall I use and how do I get started?