Jackson Labs RSR GNSS Transcoder, User Manual

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© 2017 Jackson Labs Technologies, Inc. 29
RSR GNSS Transcoder™ User Manual
is started with either manual commands (Section 4.3.2 ) or in simulation mode from power up
(Section 4.3.3 ), the previously set position will be used for the simulated position. If the fixed
position is changed while the simulation is running, the simulation position will quickly move to the
new position, limited only by the maximum dynamics configured in the SIMulation:POSition:FILTer
SCPI commands as described starting in Section
4.3.11 . When the simulation position approaches
the fixed position, the speed will reduce at the maximum acceleration rate, and the simulated position
will stop at the new fixed position. This synthesized movement from the old position to the new
position is done to prevent the GPS receiver filters from loosing lock during the transition.
For example, the following commands will start a fixed position simulation and then change only the
altitude from 500 to 2000 meters so that the simulated position changes to the new altitude with the
specified maximum velocity and acceleration:
SIM:MODE MANUAL
[optionally: SIM:POS:LLH ,,500] (it is assumed that the previously simulated height was set
to 500m)
SIM:POS:LLH 36,-115,500
SIM:POS:FILTER:MODE DYNA
SIM:POS:FILTER:VMAX 100
SIM:POS:FILTER:AMAX 0.5g
SIM:COMMAND START
SIM:POS:LLH ,,2000
The simulated position will now move from 500 meters and stop at the newly commanded altitude of
2000 meters. Any additional SIM:POS:LLH commands sent cause motion with the maximum
defined dynamics until the new position is reached.
3.8.4 Simulating from Internally Stored Motion Commands
The custom JLT motion command language defines a sequence of positioning commands that are
stored in non-volatile memory and executed sequentially during a simulation when the simulation
mode is set to SIM and the simulation position mode is set to MOTION with the
“SIMulation:POSition:MODE <FIXED | MOTION>” command. This mode is typically used by the
JLT Windows application available in late 2017. Alternatively these commands can be manually
entered through the serial port as needed. The motion vectors are stored using the
SIMulation:POSition:MOTION:WRITE command which causes the SCPI interface to enter
command entry mode. In command entry mode, one command per line is received until an END
command is received. Details on the command entry including the syntax of commands are available
starting in Section
4.3.18 .
The available commands include:
Reference - Set initial position, heading and speed
Straight - Straight motion for specified duration
Accelerate - Straight motion, change speed specified amount for specified duration
Turn - Heading change at specified latural acceleration
Climb - Change in height at specified climb rate with start and end lateral acceleration
Waypoint - Waypoint position, final heading and speed.