This page is NOT recommended NOR is it supported.
Having said that, it works for me.
Anything in this section is officially unsupported. If you need help, it will have to be from the user community in the DIY subforum only. Do NOT ask for help in any other subforum. It will likely be ignored. While these configurations work today, there is no guarantee that they will continue to do so.
Rocrail DIY Forum
Accessing both I2C buses (unsupported)
At this time, only one I2C bus can be accessed by rocnetnode. It is possible to access both I2C buses on a Rpi but to do so requires than more than one instance of rocnetnode running. To have two (or more) instances start at boot time, two files have to be modified. They are /etc/init.d/rocnetnoded and /opt/rocnet/rocnetnode.sh. To run a second instance manually:
sudo /opt/rocnet/rocnetnode -l /opt/rocnet -i rocnetnode2.ini&
To start the 2nd instance manually in the background so that you can close your telnet session:
sudo nohup /opt/rocnet/rocnetnode -l /opt/rocnet -i rocnetnode2.ini > nohup2.out 2>&1&
The requisite changes to the two startup files are fairly obvious. If you need help, please post to the DIY forum.
There is no reason why more than 2 instances cannot be run. For example: A third instance could be run that would access devices on one of the two SPI buses.
MCP23S17 SPI 16 port expander