PLCduino Architecture

The image above shows the actual PLCduino pinout:

Based on this idea we are designing the schematic of the PLCduino main board. The digital inputs will be opto-isolated and the digital outputs will be divided in two parts: relay outputs (Pin7 & Pin8) and fast transistorized outputs (Pin6 & Pin9)
The analog inputs will have a circuitry based on op-amps to isolate and convert 24V into 5V linearly