2012/7/30
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NMEA Input Command
A). Set Serial Port ID: 100 Set PORTA parameters and protocol
This command message is used to set the protocol (SiRF Binary, NMEA, or USER1) and/or the
communication parameters (baud, data bits, stop bits, parity). Generally, this command would be
used to switch the module back to SiRF Binary protocol mode where a more extensive command
message set is available. For example, to change navigation parameters. When a valid message
is received, the parameters will be stored in battery backed SRAM and then the receiver will
restart using the saved parameters.
Format:
$PSRF100,<protocol>,<baud>,<DataBits>,<StopBits>,<Parity>*CKSUM<CR><LF>
<protocol> 0=SiRF Binary, 1=NMEA, 4=USER1
<baud>
1200, 2400, 4800, 9600, 19200, 38400
<DataBits>
8,7. Note that SiRF protocol is only valid f8 Data bits
<StopBits> 0,1
<Parity>
0=None, 1=Odd, 2=Even
Example 1: Switch to SiRF Binary protocol at 9600,8,N,1
$PSRF100,0,9600,8,1,0*0C<CR><LF>
Example 2: Switch to User1 protocol at 38400,8,N,1
$PSRF100,4,38400,8,1,0*38<CR><LF>
**Checksum Field: The absolute value calculated by exclusive-OR the 8 data bits of each
character in the Sentence, between, but excluding “$” and “*”. The hexadecimal value of the most
significant and least significant 4 bits of the result are converted to two ASCII characters (0-9, A-F)
for transmission. The most significant character is transmitted first.
**<CR><LF>
: Hex 0D 0A
B). Navigation lnitialization ID
：
101 Parameters required for start
This command is used to initialize the module for a warm start, by providing current position
（
in X,
Y, Z coordinates
）
,clock offset, and time. This enables the receiver to search for the correct
satellite signals at the correct signal parameters. Correct initialization parameters will enable the
receiver to acquire signals more quickly, and thus, produce a faster navigational solution.
When a valid Navigation Initialization command is received, the receiver will restart using the input
parameters as a basis for satellite selection and acquisition.
