Hi, I need to build a daligateway that has a power supply to power the dali bus line with a limited current. Also communicating slaves thru that bus line. Sometimes technicians can accidentally put 220VAC to the bus. In this term, circuit should detect the 220VAC and protect itself and it should also communicate with slaves while 220VAC not connected to this line instead of devices communicated thru this bus. You can see simple Dali comminication and current limiter circuit below. Bridge rectifier is used to prevent wrong polarization but i will not use it, because the device will be the source. Any ideas?