🔍 Key Concepts

• Digital Selective Calling (DSC) test procedures in GMDSS equipment manuals • Use of a coast station’s MMSI (Maritime Mobile Service Identity) vs FCC call sign in DSC operations • Purpose and correct use of the DISTRESS button under the red cover vs routine/test calls

💭 Think About

• For a routine DSC test with a coast station, what type of call category is normally used: distress, safety, urgency, or routine/test? • When you place a directed DSC call to one specific coast station, do you usually identify it by its FCC call sign (letters) or by its MMSI (numbers)? • Would a test call ever be sent as an ALL SHIPS call, or should it be addressed to a specific station?

✅ Before You Answer

• Confirm from your DSC radio knowledge which function uses the red covered distress button and whether that is ever used for tests. • Verify how a coast station is uniquely addressed in DSC: by MMSI number or by call sign letters. • Check whether ALL SHIPS DSC calls are appropriate for simple radio checks or if they are reserved for specific types of messages (e.g., safety, urgency).