For installations where more than 8 inputs and/or outputs are required at a site, the 8 way expansion boards can be connected. Up to 3 additional expansion boards can be connected, providing up to 32 inputs and/or outputs at a location. Each additional expansion board is connected via a communication cable. The most common application for the expansion boards are in pump sheds, where multiple valves are wired back to a pump site, where pump control and monitoring is required in addition to multiple valve control.