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RSR GNSS Transcoder™ User Manual

3.8.2.1 Connecting a Rockwell Collins RSR SAASM Puck

and/or MicroGRAM SAASM GPS

The RSR GNSS Transcoder™ will initialize and control externally-connected Rockwell Collins RSR
SAASM Puck and MicroGRAM SAASM Receivers via the RS-232 serial port. For these receivers to
communicate with the RSR GNSS Transcoder™, the NMEA protocol including input messages must
be enabled manually in their configuration by Rockwell Collins by ordering the NMEA versions of
these products. The Rockwell GPS receivers will have only ICD-153 interfacing enabled by default,
and the NMEA capability must be configured by Rockwell Collins at their factory upon user-request.
Also the 1PPS output mode should be configured to UTC during assembly-configuration of the
receiver. Please contact Jackson Labs Technolgies, Inc. for additional information regarding the
required receiver configuration. Special features that are available with the Rockwell Collins
SAASM receivers include Y-Tracking status, keyfill status, anti-spoofing status, zeroize, 1PPS
quantization error and DAGR assisted warm-start mode control and status. See Section

4.10

for

details of the supported SAASM GPS relevant SCPI commands. Jackson Labs Technologies, Inc. has
partnered with Rockwell Collins to create a special timing-enabled version of the internal
MicroGRAM and GB-GRAM SAASM firmware. This software version has been security-approved
and is only available to JLT customers. It is required to be used on the Rockwell Collins GPS
SAASM receiver to achieve the best timing performance from the unit and thus recommended (but
not required) on systems using the CSAC oscillator disciplining option.

3.8.2.2 Connecting a uBlox GNSS Receiver

The RSR GNSS Transcoder™ will also control products from uBlox, viz. uBlox generations 5
through 8 GPS and multi-GNSS receivers. The RSR GNSS Transcoder™ will work with both
standard and fixed-position timing receiver versions of the uBlox 5 through 8. The uBlox receiver
should start up at the default baud rate of 9600, and the RSR GNSS Transcoder™ will configure the
baud rate of the uBlox GNSS receiver to 38400 automatically via the built-in RS-232 serial port. The
RSR GNSS Transcoder™ communicates with the uBlox receivers using both the NMEA output and
uBlox Binary input and output commands. The RSR GNSS Transcoder™ also configures the uBlox
receiver’s 1PPS output for optimum settings for the GPSDO operation of the RSR GNSS
Transcoder™. The entire uBLox GNSS receiver configuration process is transparent to the user.
Special features available with the uBlox 5 through 8 GNSS receivers include a Fixed Position/ Auto
Survey mode, automatic and manual dynamic Kalman filter settings, ECEF position and velocity,
antenna delay setting, jamming level monitoring, concurrent GNSS reception capability (uBlox-8
and later), and 1PPS quantization error monitoring/compensation. See Section

4.10

for details on the

supported SCPI commands.

3.8.3 Manually entering Lat/Long/Height Simulation

Coordinates

When the RSR GNSS Transcoder™ is operating in simulator mode, it can use position information
provided from a JLT-custom motion command language or from a fixed position entered through
SCPI commands. The fixed position to be simulated as entered through SCPI commands is stored in
non-volatile memory and will be retained through a power cycle. The SIMulation:POSition:LLH and
SIMulation:POSition:ECEF commands are used to enter or query the current fixed position in
Latitiude/Longitude/Height or Earth Centered Earth Fixed (ECEF) coordinates. When the simulation