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4. INSTALLATION
4-13
NRM: NAVTEX receiver mask
This command is used to manipulate the configuration masks that control which messages are
stored, printed and sent to the INS port of te NAVTEX receiver.
$--NRM,x,x,hhhhhhh,hhhhhhh*hh<CR><LF>
message type mask (SEE NOTE 4)
transmitter coverage area mask (SEE NOTE 3)
frequency table indes, 1 to 9 (SEE NOTE 2)
function code, 0 to 9 (SEE NOTE 1)
NOTE 1: The function code is used to further identify the purpose of the sentence. The meaning of the function
code is as follows:
0 - request messages for the given mask
1 - set/report the storage mask
2 - set/report the printer mask
3 - set/report the INS mask
4 to 9 - reserved for future use
NOTE 2: The frequency indicator identifies the frequency that the NAVTEX message was received on:
1 = 490 kHz
2 = 518 kHz
3 = 4209.5 kHz
4 through 9 are reserved for future use
NOTE 3: The transmitter coverage area mask is defined as a 32 bit hex field where the least signification bit represents
transmitter coverage area "A", the next bit is "B" and so on up to bit 25 which is "Z". Bits 31 through 26 are reserved for
future use and are set to zero. To select a transmitter coverage aera, its corresponding bit should be set to one. To
deselect a transmitter coverage area its corresponding bit should be set to zero.
NOTE 4: The message type mask is defined as a 32 bit hex field where the least significant bit represents message
type "A", the next bit is "B" and so on up to bit 25 which is "Z". Bits 31 through 26 are reserved for future use and are set
to zero. To select a message type its corresponding bit should be set to zero.
When another device (for example an INS) wishes to set one or more of the bit masks it sends
one or more NRM sentences to the NAVTEX receiver. When another device wishes to determine
the current values of the bit masks it sends a query sentence to the NAVTEX receiver as follows:
$--CRQ, NRM*hh<CR><LF>
On receiving this query, the NAVTEX receiver will respond with one NRM sentences for each
mask type and frequency combination that it supports. For example a NAVTEX receiver which
support separate storage, printer and INS masks for each of three receiver frequencies will
return a total of nine NRM sentences in response to the above query.
Example
$INNRM,2,1,00001E1F, 00000023*57
This example specifies that message identifiers "A", "B" and "F", received from transmitter areas
"A" to "E" and "J" to "M" on 490 kHz should be sent to the printer port when they are received. Note
that this command sets the printer mask for future use; there is no immediate output generated
as a result of receiving this command.
Example
$INNRM,0,2,00001E1F,0FFFFFF*21
This example requests that all currently stored messages of all message type, received from
transmitter areas "A" to "E" and "J" to "M" on 518 kHz should be immediately returned to the
requesting device as a series of NRX sentences. Note that this command does not update any of
the stored masks.