Connection interface for modular electronics

[DanioIO]

Hi,
Im trying to make a simple modular device one master board and couple of slaves. Im currently stuck at the interface which would be used to communicate between master and slaves - i need two way communication. All modules will be connected in parallel using only two wires.
I though about using I2C SRAM buffer on every module so the master can read data from this memory, but i cant find any memory that supports more than 4 addresses - does any one know and module which i2c address can be choose by the user? I could implement this memory on a microcontroller acting as an i2c slave but this solution has one problem - i need two i2c interfaces one for the master and one for the slave.
Does any one know any way to connect master to couple of slave using only two wires and a data buffer?

[Tandy]

You could use SPI and create a shift register cascade on the boards so you can select each one by stepping through the shift register to active each boards chip select.

[magetoo]

Does any one know any way to connect master to couple of slave using only two wires and a data buffer?

CANbus?  It's widely used in automotive, some microcontroller families have it as an option.  Here is a decent intro to CAN.

(I'm ignoring the RAM/buffer part of what you said, because I have no idea if that's necessary or just something you made up on the spot to help solve the problem.  CAN does have "remote frames" though, which can do something similar.)

Or along the same lines, maybe LIN, which I don't really know much about.

It would help if you told us a bit more, like distances involved, data rates, hobby or industry, and that sort of thing.

[lapm]

I think we need a bit more information about use of this connector...

Whats sort of distances you are looking for and what sort of speed you need? Also how many signals you need to get over from master to slave?

Distance effects what is reasonable system to use to get this data over...