Is it necessary to use a sound card to ingest the EMWIN signal?
No. A sound card was used in the prototype to function only as an analog-to-digital converter. It was proposed simply because it is readily available, of relatively low cost, and will plug into a PC that is needed to run the software that will process the digital output from the sound card. A potential manufacture may of course elect to use other design approaches to avoid the use of the sound card. Some older sound cards will not work. However, at least 5 types were tested by NESDIS and 4 of the 5 were found to be reliable. Refer page 18 of the 19.2 specification.
