Thanks to all I have learned more from this thread than I thought I didnt know.
The domain in this case is the system. Its a networked system of 7 Gent vigilon panels. There are plans to build a mirror image of the building on a site opposite both controlled from the same supervisory pc and I guess this will be domain 2. In this case Node is the particular panel each having up to four loops and the OS is the outstation which may be a detector, call point or interface. As the RP on behalf of this client I now face the job of re-labelling all the device information to make it a little more understandable for the security guys. Just wondering what to do after lunch...
Thanks for this Kurnal. I can now understand the need for a word such as 'DOMAIN' in these circumstances. OS is again a new one on me having normally only seen Device/Sensor etc. on the panels I have worked on. Outstation is a great word and sounds so much better than device. I think I could charge more for installing an outstation than a device, and will now start using it on my quotations!
Anyone else got any examples of 'hi-tech' words being used for simple parts of a fire alarm systems?