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Digital Selective Calling capable?
Does your marine VHF radio have a red flap labeled DISTRESS? If yes, then you most likely have a radio capable of Digital Selective Calling (DSC). The DSC capable radio supports a host of safety and convince features. The most important feature is that the radio can quickly send out a formatted digital distress call to the Coast Guard and all DSC radios near your location. The formatted data digital message will include the hailing vessel’s name, GPS location of the vessel and the nature of distress. This would be the quickest way to get a response to an emergency.
Another communication feature of the DSC capable radio is the ability to call other DSC radio or a group of radios selectively. This feature is similar to a texting, where one selects one or more phone numbers, composes a message and sends the message. A receiving phone gets the massage and gives an alert. The DSC capable radio process is similar. One selects a MMSI number from the radio’s stored MMSI list, composes a message (the message could be to join the caller on channel 9, 68, 69, 71, 72 or 78 for a conversation) and sends the message. The message will be sent on channel 70 (channel 70 is reserved for digital calling only! No voice calling allowed on channel 70). The selectively called DSC always monitors channel 70 and when a message directed to the radio or an emergency message is received, the radio sounds an alarm (audio tone) and display a message. The selective calling feature is just one of the host of options available to DSC capable radios.
Radios with DSC need two additional installation procedures:
1) All owners of DSC radios MUST obtain a MMSI Identifier.
http://www.boatus.com/MMSI/MMSI/ObtainMMSI#! or by calling 1-800-563-1536,
2) Radio must have access to a GPS location.
The position of the vessel can be obtained by the radio from an internal GPS (if equipped) or external GPS. If the radio has an internal GPS then one must consider connecting the GPS signal to other equipment (chart plotter, Radar.). If the radio does NOT have an internal GPS than the radio MUST be connected to a GPS device with a signal cable. It is critical that the GPS device be operational whenever the radio is operational. See below for a description of the connection process.
To comply with FCC regulations a warning sticker must be mounted in a location that can be easily viewed from the location of the GX2200.
Testing
The functioning of the DISTRESS button (red button) can NOT to be tested. The activation of the DISTRESS function sends out a distress signal, repeatedly (approximately every 4 Minutes) until another DSC radio responds to the distress call. The message can be paused or stopped by canceling the distress call or shutting the radio off.
If you radio has the DST test feature and you know some that has a radio with the test feature then us the following procedure:
1) Select DSC test from the menu
2) Select the MMSI number of the radio that you are calling from your directory or manually enter it
3) Send
The receiving radio will:
1) receive the message,
2) give an audio alert,
3) display a message that an ACK message was received along with the MMSI number of the calling station.
If one does not have the test feature than one can make a call to another radio using the” DSC individual” selection of the DSC menu.
1) Select “DSC individual” from the menu
2) Select the MMSI number of the radio that you are calling from your directory or manually enter it
3) Select the working channel (68, 69, 71, 72, and 78) that you wish to have a conversation on
4) Send the request
5) Set the radio to the working channel chose above and wait for a call.
The receiving radio will:
1) Receive the message,
2) Give an audio alert,
3) Display a message that an individual message was received along with the MMSI number of the calling station and the receiving radio will switch to the working channel.
4) Pick up the mic and make a call to the calling radio.
A fully functioning DSC radio (valid MMSI number, active GPS) will greatly increase the chance of getting aid when a problem arises. With a press of a button a distress message will be sent and repeated on a 4 minute interval.
External GPS connection
If the radio does not have an internal GPS than the radio must get a location of the vessel from a GPS receiver or Chart plotter. The connection is a NMEA two wire protocol. Simply connect the plus ( + ) NMEA from the GPS source to the plus NMEA wire on the radio. Similarly, connect the minus ( - ).
Does your marine VHF radio have a red flap labeled DISTRESS? If yes, then you most likely have a radio capable of Digital Selective Calling (DSC). The DSC capable radio supports a host of safety and convince features. The most important feature is that the radio can quickly send out a formatted digital distress call to the Coast Guard and all DSC radios near your location. The formatted data digital message will include the hailing vessel’s name, GPS location of the vessel and the nature of distress. This would be the quickest way to get a response to an emergency.
Another communication feature of the DSC capable radio is the ability to call other DSC radio or a group of radios selectively. This feature is similar to a texting, where one selects one or more phone numbers, composes a message and sends the message. A receiving phone gets the massage and gives an alert. The DSC capable radio process is similar. One selects a MMSI number from the radio’s stored MMSI list, composes a message (the message could be to join the caller on channel 9, 68, 69, 71, 72 or 78 for a conversation) and sends the message. The message will be sent on channel 70 (channel 70 is reserved for digital calling only! No voice calling allowed on channel 70). The selectively called DSC always monitors channel 70 and when a message directed to the radio or an emergency message is received, the radio sounds an alarm (audio tone) and display a message. The selective calling feature is just one of the host of options available to DSC capable radios.
Radios with DSC need two additional installation procedures:
1) All owners of DSC radios MUST obtain a MMSI Identifier.
Currently, there are three organizations that can provide the MMSI identifier to recreational boaters:
Sea Tow (free) http://mmsiregister.seatow.com or by calling 1-800-473-2869,
Boat US (free to members all others $25)http://www.boatus.com/MMSI/MMSI/ObtainMMSI#! or by calling 1-800-563-1536,
Power Squadron (free) http://www.usps.org/php/mmsi_new/.
The registration will require extensive information about the vessel and person to contact in the event of an emergency. The MMSI number must be entered in the radio. Think of the MMSI number the same as a phone number. It is a number that is unique and associated via a world-wide-directory to your vessel.
2) Radio must have access to a GPS location.
The position of the vessel can be obtained by the radio from an internal GPS (if equipped) or external GPS. If the radio has an internal GPS then one must consider connecting the GPS signal to other equipment (chart plotter, Radar.). If the radio does NOT have an internal GPS than the radio MUST be connected to a GPS device with a signal cable. It is critical that the GPS device be operational whenever the radio is operational. See below for a description of the connection process.
To comply with FCC regulations a warning sticker must be mounted in a location that can be easily viewed from the location of the GX2200.
Testing
The functioning of the DISTRESS button (red button) can NOT to be tested. The activation of the DISTRESS function sends out a distress signal, repeatedly (approximately every 4 Minutes) until another DSC radio responds to the distress call. The message can be paused or stopped by canceling the distress call or shutting the radio off.
If you radio has the DST test feature and you know some that has a radio with the test feature then us the following procedure:
1) Select DSC test from the menu
2) Select the MMSI number of the radio that you are calling from your directory or manually enter it
3) Send
The receiving radio will:
1) receive the message,
2) give an audio alert,
3) display a message that an ACK message was received along with the MMSI number of the calling station.
If one does not have the test feature than one can make a call to another radio using the” DSC individual” selection of the DSC menu.
1) Select “DSC individual” from the menu
2) Select the MMSI number of the radio that you are calling from your directory or manually enter it
3) Select the working channel (68, 69, 71, 72, and 78) that you wish to have a conversation on
4) Send the request
5) Set the radio to the working channel chose above and wait for a call.
The receiving radio will:
1) Receive the message,
2) Give an audio alert,
3) Display a message that an individual message was received along with the MMSI number of the calling station and the receiving radio will switch to the working channel.
4) Pick up the mic and make a call to the calling radio.
A fully functioning DSC radio (valid MMSI number, active GPS) will greatly increase the chance of getting aid when a problem arises. With a press of a button a distress message will be sent and repeated on a 4 minute interval.
External GPS connection
If the radio does not have an internal GPS than the radio must get a location of the vessel from a GPS receiver or Chart plotter. The connection is a NMEA two wire protocol. Simply connect the plus ( + ) NMEA from the GPS source to the plus NMEA wire on the radio. Similarly, connect the minus ( - ).