All very mysterious. A college project, I assume. But RS-232 is a very handy protocol. Almost universal, even. My own interest (casual, of course) used to be in collecting the pin-outs of the various data interfaces found on the back of various pieces of equipment. For instance, on some infusion pumps you can pick out battery voltage on certain pins. For real fun, you can get bits of kit talking to each other (ie, sharing data) – hardware hacking, you might call it (and before anybody starts moaning – only on condemned junkers, of course). Maybe I’ll restart my collection and write my own pamphlet all about it (…yes, sad I know)!

Yes a school project Geoff. I was more interested in establishing a relatively simple method of managing parameter alarm hierarchies and providing alarm sounds based on the findings of human factors research rather focussing on the RS232 communications. Once I'd got the bi-directional, interrupt-driven, communications functioning, the oximeter alarms/alarm-limits/volume/settings under control and parameter data collection then I was happy.

is there anyway that i might be able to get the communication protocol from you with permission from joe for a particular model of probe?