So I am after tests. I did test 2 times: one time on stable 2.563 and second on latest beta 2.2703. Both failed but here are the results

:
I connected my S0 meter to PiFace Digital2 input 0 (schematic from domoticz wiki, source +12V) and Photo Sensor is connected to input 2 (source 3.3V).
Stable 2.563:
I can see RFXMeter icons in Device window and after enabling them they report each 10 seconds but they does not increment / count.
If I add S0 meter input into Domoticz (called: 0_test_S0) there are not any rising/falling edges.
Photo:
However on my multimeter I can see drops from 0.5V to ~0. And there is a beep sound

I am curious if this voltage - in period when there is no impulse - is not too low? I used this schematic
http://www.domoticz.com/forum/download/file.php?id=188 and of course 2N7000 is onboard.
I also tried to run your pfinit.py and I had seen blinking leds,then restarded domoticz with no success.
My last observation, If I click on Photo Sensor input icon (2_test_photo_sensor) I can see rising/falling edges so Domoticz see impulses, photo:
but RFXMeter still does not incerase.
Beta: 2.2703:
I can not see RFXMeter icons, only "Lighting 1" icons. The RFX are just simply not present in Device window. Initializing PiFace from python script does not improve situation

.
I would like to try your exact beta version, could you please give me a link to download it? Because I just only see v2.2703.
Thanks
Maciek
RPI2 + RFLink + PiFace D2 + Aeon Z-Wave Gen5 + Foscams FI9821P&R2 + MySensors + UPS APC Back-UPS 950VA
RPI2 + RFXtrx433e + Foscams FI9821P + MySensors + UPS APC Back-UPS 950VA
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