Schneider electric zelio compact plc modules schneider electric sr2a101bd this zelio logic module is a compact smart relay designed for simple control systems the unit has 10 io 6x discrete inputs4x relay outputs and a supply voltage of 24v dc the module also has large lcd screen that makes the system easy to use the module is easy to install and program using either fbd or ladder and the zelio soft 2 programming software is intuitive to use zelio logic smart relays are operationally