ok so i have a ckt iam trying to understand they have a SN6517B with its B pin connected to the Emitter and the A pin connected to the Base and the collector is connected to ground.This transceiver is used for transmission of DMX data.What exactly is this transistor doing and why would they put it on the signal lines?thanks
http://www.ti.com/lit/ds/symlink/sn65176b.pdf
https://www.fairchildsemi.com/datasheets/BS/BSS64.pdf
http://www.ti.com/lit/ds/symlink/sn65176b.pdf
https://www.fairchildsemi.com/datasheets/BS/BSS64.pdf