A relay module is a separate hardware device used for remote device switching. With it you can remotely control devices over a network or the Internet with additional IO.
24 Digital Input multiplex provides a single analogue output (0-10V or 4-20mA)
Digital Input Multiplexer converts 4 digital input signals into a single multiplexed voltage analogue output and is compatible with nearly all BMS controllers.
8 Digital Inputs to 1 Analogue input multiplexer