4-channel binary input at 230V AC 35mm dil-rail housing

Caution when working on 230V AC power, it is extremely dangerous!

For reasons of space was a 4 out of fold development input for 230V AC.
its switching threshold can by changing the pull-up resistors in the range of
24V AC to 215V AC can be varied.
Its input current at 230V AC is approximately 2mA. He has a capacitor power supply,
thus the losses are negligible.
If we replace the WIMA capacitor C1 through a
Resistance can be operated with the relevant input DC 12-30V
But now .... only time to Schematic of a single input

At the terminals on the right the input voltage is applied. C1 and R1 are used as a resistor. About D1 is the
capacitor C2 charged. In case of negative half-cycle to terminals X21-1 and X21-2 blocks D1.
The capacitor C 1 is now transhipped via D2. R2 is used to current limitation the optocoupler and reduces ribble extent that downstream of the Schmitt trigger by the ripple does not switch. I.e. the ripple must be less than the hysteresis of the Schmitt trigger.
The input and switch-off level kan be seen in Table below:

I opted for 10kOhm, here the input switches at about 110V.
But it's something that must now complete schematic ago: