Commands
Chapter 5
EuroPak-15a Receiver User Manual Rev 5
47
5.3.2
ASSIGN
Assign Individual Satellite Channels
The
ASSIGN
command should only be used by advanced users.
This command may be used to aid in the initial acquisition of a satellite by allowing you to override the
automatic satellite/channel assignment and reacquisition processes with manual instructions. The command
specifies that the selected tracking channel should search for a specified satellite at a specified Doppler
frequency within a specified Doppler window.
The instruction will remain in effect for the specified SV channel and PRN, even if the assigned satellite
subsequently sets. If the satellite Doppler offset of the assigned SV channel exceeds that specified by the
window
parameter of the
ASSIGN
command, the satellite may never be acquired or re-acquired. If a PRN has
been assigned to a channel and the channel is currently tracking that satellite, when the channel is set to
AUTO
tracking, the channel will immediately idle and return to automatic mode.
To cancel the effects of
ASSIGN
, you must issue one of the following:
•
The
ASSIGN
command with the
state
set to
AUTO
•
The
UNASSIGN
command
These will return SV channel control to the automatic search engine immediately.
1. Assigning a PRN to an SV channel does not remove the PRN from the search space of the automatic
searcher; only the SV channel is removed (i.e. the searcher may search and lock onto this PRN on
another channel). The automatic searcher only searches for PRNs 0 to 37 for GPS channels and 0 to 50
for Galileo channels.
2. Assigning an SV channel will set the
Channel Assignment
bit to 1 for forced assignment in the
Channel
Tracking Status
field of the
RANGE
log. The
RANGE
log is specified in
.
3. The doppler field applies to L1 GPS and Galileo channels only.