RoyalTek REB-3000 - Manual (Page 24)

RoyalTek RGM-3000/REB-3000
GPS Module Operational Manual)
19
0x04 Clear Memory – Cold Start =1
Development Data On/Off
Use this command to enable development
data information if you can not get the
commands accepted. Invalid commands
generate debug information that enables the
user to determine the source of the
command rejection. Common reasons for
input command rejection are invalid
checksum of parameter out of specified
range.
Table 16 contains the input values for the
following examples:
1. Debug On $PSRF105,1*3E
2. Debug Off $PSRF 105,0*3F
Table 16 Development Data On/Off Data Format
Name Example Units Description
Message ID $PSRF105 PSRF105 protocol header
Debug 1 0=Off , 1= On
Checksum *3E
End of message termination
Calculating Checksums for NMEA
Input
The Checksum is the 8-bit exclusive OR of all
the characters after $ and before *. (Not
including $ and *)
SiRF Binary Protocol
The serial communication protocol is designed
to include:
● Reliable transport of messages
● Ease of implementation
● Efficient implementation
● Independence from payload
Protocol Layers Transport Message
Start
Sequence
Payload
Length Payload
Message
Checksum
EndSequence
0xA01,
0xA2
Two-bytes
(15-bits)
Up to 210-1
(<1023 )
Two-bytes
(15-bits)
0xB0,
0xB3
0xYY denotes a hexadecimal byte value. 0xA0 equals 160.
Transport
The transport layer of the protocol
encapsulates a GPS message in two start
characters and two stop characters. The
values are chosen to be easily identifiable
and such that they are unlikely to occur
frequently in the data. In addition, the
transport layer prefixes the message with a
two-byte (15- bit)message length and a
two-byte(15-bit) choice of a 15-bit values for
length and check sum are designed such
that both message length and check sum
can not alias with either the stop of start
code.
Message Validation
The validation layer is of part of the transport,