Retrieving infos from multiple PICs on a bus/chain

[flotulopex]

Hello,

I'm building up a system using twenty-two PICs ("sensor") connected to one PIC ("master").

The distance between each "sensor" PIC is two meters so the bus or daisy-chain will be around 25 meters long, end-to-end to the "master" PIC.
<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=2084&stc=1&d=119234804 4">
The "sensor" PICs control photodiodes and have to provide a binary value to the "master" PIC anytime it has changed. They also have to provide their ID (i.e. PIC's #).

The "master" PIC will gather and convert this info to an 0V to 10V information for the BMS (Building Monitoring System = alarm visualisation system).

Since I have a few of them in my drawer, I have chosen 10F202 PIC as the "sensor" PICs and will see if the same one can be use as the "master" one.

Question: to get me started correctly, how do I connect the PICs (I2C, SPI,..?) and how am I retrieving their information?