Specifications

Command/Response Formats 131
Commands
<packed data> Parameter:
Table 6.64: RPC Message Structure
Parameter Type num. of bytes Description
data length unsigned short 2 number of bytes in <packed data> part
packed data unsigned char[] data length see below
ChkSum unsigned short 2 Accumulative unsigned short summation of
the <packed data>, after <data length> before
<ChkSum>
Table 6.65: RPC Packed Parameter Descriptions
Data
Type
Symbol Range Resolution
Compress
Num. Bits
Description
double rcvtime 0 - 604800000 1 msec 30 Receiver time in GPS milliseconds
of week
char[4] site ID 32 Receiver’s four character’s site ID
long PRN 32 SVPRN for the satellites which
have data in this message. It is a
bitwise indication. Starting from
least significant bit, bit 1
corresponds toSVPRN #1, bit 2
corresponds to SVPRN #2, and so
on. Bit value of 1 means that
SVPRN has data in this message, 0
otherwise.
For each satellite whose corresponding bit in PRN is ‘1, the following data will be repeated, i.e., sent
once for PL1 data and a second time for PL2 data.
double PL1 or
PL2
1.0e-10
seconds
31 Pseudorange in units of 1.0e-10
seconds (or 0.1 nanoseconds).
Multiply this value by 1.0e-10 to
get pseudo-range in seconds. A
zero value indicates bad
pseudo-range
char WN 1 Warning bit
1- bad carrier phase and has
possible cycle-slips
0 - good carrier phase
Sign 1 1 Carrier phase sign bit
1 - negative carrier phase value
0 - positive carrier phase value