How to set both per-node and global channels

I just installed phpfreechat and it seems to be working fine, but I can't figure out how to get the channels to behave the way I want. I would like to have both a node-specific channel and a site-wide general channel. From what I can tell, node-specific is the default behavior if I don't supply any channel names, but this gets overridden when I add a general channel. Is there a way to get both channels working at the same time?