Hi,
Yes, but remember that they are all "blocking" commands, that is if you have a SERIN at one place in your program and it's wating for data to come in then your "other" SERIN/DEBUGIN/HSERIN etc is effectively not listening. If you need to be able to receive data from multiple sources simultanously then using interrupts on a PIC with multiple (E)USART is the way to go. On the other hand, if you can communicate with your devices sequentially (first one, then the next, then the next and so on) then you can do it with multiple SERIN/SEROUT.

/Henrik.