DSC is the marine
version of SELCAL for aviation. It is - ignoring the emergency
functions for a moment - a "speed dial" type convenience.
- - You gather from other friendly boats their MMSI numbers and enter them into the DSC library with a short "word" to identify the entry - like "Bob" or "Joan" or a short version of the boat's name.
- - When you want to "call" them you find a VHF
channel that is not in use or reserved and set your DSC radio
for that channel. Then activate the DSC call function, select the "word/name" and again press the DSC call button. Your radio will automatically call the other selected boat's DSC radio and if they have their radio turned on, re-channelize their radio to your operating channel along with sound a "telephone" type ringing noise
from their radio. When they "answer the phone" by depressing their mic button, you are "live" and can carry on your conversation.
- - This system bypasses all the needs to wait for and getting on a net to try to contact your friends. It operates similar to a telephone "speed-dial" in that you select their name and press a button and everything else is automatic (as described above).
- - As to entering other MMSI's such as USCG and others you need to get their MMSI number which they may or may not make available to the public.
- - Of course when you first get the radio you need to "program" in your own MMSI number which can be found on your "Ships Radio Station Authorization" (radio license) in the 10th block down counting from left to right then down. It is labeled "Ship Station Identity". If that block is blank then you need to get a MMSI from the FCC or use a service
like BoatUS to get one.
- - Likewise your friends need to locate their own MMSI from their ship radio license
and exchange that information with you.
- - As to your question #2, you can download a free NMEA
reader like: NMEALOGR from a Google
Search and then install the program and connect the NMEA
output from your radio to your computer. It will then display what is coming out of the radio's NMEA - if anything. You can also download free GPS
reader like VisualGPS and that will probably also display the NMEA sentences coming from the radio. Additionally the GPS
NMEA readers can be used to see if your GPS is functioning and outputing data.