$ cat /media/1wire/10.BCD8ED010800/temperature
$ cat /media/1wire/10.BCD8ED010800/power
power file shows that it's powered parasitically.
I don't know how many sensors I can connect to 100 meeter cable before I have to add additional power, but if I got reading from 100 meeter cable, then I am sure I get readings of many sensors with external power. Just found guidelines page. In my case, I probably need total of 50 meters of wiring.