With 2 x 3 in. board size, Ethernet (IP)-controlled IA-3721-E includes 2 relays, 2 digital inputs, Ethernet port, and built-in Peer-to-Peer function with communication health report function. Stand-alone operation negates need for host computer, and P2P System comprised of IA-3721-E controllers may be added to any existing facility (without changing any parameter) using any copper, fiber, or wireless network.