Dwyane

Thanks for the reply and sorry for my lack of clarity. I really must post when I'm fresh and not so late at night.

I have the Serin wait and the timeout with a pullup resistor and they work fine with the exception that when the receiver is in fact receiving something the timeout fails. I understand that this is just how it is when using the timeout in Serin. Its essentially the same as if you don't have a pull-up/pull-down resistor to eliminate noise - the transducer line/power supply/component noise with high opamp amplification keeps retriggering the timeout.
SERIN PORTB.0,T300,200,NOSERIN,[CODE],B9

As the receiver is ultrasonic (currently using a 40Khz transducer) I've found that there are many things that emit ultrasonics at or close to that frequency, enough anyway to keep the PIC Serin timeout retriggering. For instance a previous computers power supply two rooms away from the reveiver kept its Receive Indicator LED flickering and the timeout from working. An additional problem is that a transducer will resonate most easily at a particular frequency, 40kHz for example but it'll also resonate at other frequencies just not as easily - a good cause for me to investigate bandpass filters!

This is why I'm after a way other than the program cycle to keep a time count and to turn the receiver off to save battery power when stuck in the Serin timeout.

Do you think the Timer1 part of my first post is a viable option?

Andrew.