Jackson Labs RSR GNSS Transcoder, Руководство пользователя

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RSR GNSS Transcoder™ User Manual
2.3 Connecting to Target GPS Receiver’s Antenna Input
The RF output from the RSR GNSS Transcoder connects directly to the antenna input on the target
GPS receiver. The SMA GPS L1 RF connector is labeled in
Figure 2.1 . In addition to an RF output,
this connection also provides a 180 Ohm DC load for the antenna output voltage from the target GPS
receiver as some GPS receivers provide 3.3V or 5V to the antenna and require an antenna current to
operate properly.
PLEASE NOTE: If the target receiver’s antenna output voltage is higher than
6V, then a DC block is required between the RSR GNSS Transcoder™’s RF output and the
target receiver’s antenna input. An example of this is the Symmetricom/Microsemi XLI
reference, it outputs 12V DC which would damage the 180 Ohms DC termination resistor.
Use
an appropriate RF cable to connect the SMA RF output to the antenna input of the target receiver, and
add a DC block as necessary.
2.4 Simulation Control
This section describes basic command examples for setting up a fixed position simulation with
specified location and start time, adding manual start/stop control. These commands are entered at
the SCPI command prompt in the terminal program described in Section
2.2 . Each command is
terminated with a carriage return character (Enter key).
For manual START/STOP simulation control, set the simulation mode to manual:
SIM:MODE MANUAL
To set the fixed position of the simulation enter the command:
SIM:POS:LLH lat,lon,height
where lat and lon are latitude and longitude in degrees and height is in meters above the GPS
ellipsoid (not Mean Sea Level height). A user may enter one or more of the lat/long/height
parameters, so for example to just change the simulated height enter:
SIM:POS:LLH ,,height
The simulated time can be manually set. This means the GPS receiver will indicate the start time and
date as soon as the simulation commences. This allows simulating any time/date in the future or past
as required.
To set the assigned start time, set the time mode to
Assigned
mode:
SIM:TIME:MODE ASSIGNED
Next, set the assigned start time and date with the commands:
SIM:TIME:START:TIME hh,mm,ss.sss
and
SIM:TIME:START:DATE yyyy,mm,dd
Finally, start the simulation with the command:
SIM:COMMAND START
The simulation will start immediatly after the Enter key has been received, and the GPS receiver
should indicate the selected time/date.
The simulation will run indefiniately or until stopped with the command:
SIM:COMMAND STOP