ashtech DG16 Reference Manual page 218

If the command is set without a period, the DG16 uses the period set by the
$PASHS,RCI command If the $PASHS,RCI command is issued after this message
period has been set, the period resets to the RCI setting.
$PASHR,MCA
This message is not output unless the receiver is tracking at least one satellite. The
MCA message contains some of the same measurement information as is
contained in the MBN message: doppler, raw pseudo-range, full carrier phase,
satellite PRN number, elevation, and azimuth. A separate MCA message is output
for each satellite being tracked. The structure of the message is in the format:
$PASHR,MCA,<Ashtech type 3 data string + checksum>
Table 7.8 outlines the data string format.
Field
unsigned short
[sequence tag]
unsigned char [left]
unsigned char [svprn]
unsigned char [elev]
unsigned char [azim]
unsigned char [chnind]
unsigned char
[warning]
198
Table 7.8. $PASHR,MCA Data String
Bytes
2 Sequence ID number in units of 50 ms, modulo 30 minutes
1 Number of remaining MCA messages to be sent for current epoch
1 Satellite PRN number (1 to 32 for GPS and 33 to 64 for SBAS)
1 Satellite elevation angle in degrees
1 Satellite azimuth angle in increments of 2 degrees
1 Channel (1 to 14) assigned to the satellite
1 Warning flag:
• Bit 1 set - See note below
• Bit 2 set - See note below
• Bit 3 set - Carrier phase questionable
• Bit 4 set - Code phase questionable
• Bit 5 set - Code phase integration questionable
• Bit 6 set - Not used
• Bit 7 set - Possible loss of lock
• Bit 8 set - Loss of lock; counter reset
The interpretation of bits 1 and 2 is as follows:
[Bit 1, Bit 2]
• [0, 0] Same as 22 in good/bad flag (see next field)
• [1, 0] Same as 23 in good/bad flag
• [0, 1] Same as 24 in good/bad flag
Note that more than one bit may be set at the same time, e.g., if bits
1, 3, and 6 are set at the same time, the warning flag is 37 (1 + 4 + 32)
DG14 and DG16 Board & Sensor Reference Manual
Content