RDS Satspeed Use and care manual

KIT -P/SATSPEED
GPS Speed Interface
Installation, Calibration and Operation
Doc. No. S/DC/500-10-592 : Issue 2 : 28/8/09 Page 1-UK592200.DOC
Part No. Description Qty
S/SR/385-1-001 Satspeed Interface 1
S/CBL/TIE/001 Cable Tie 25
Application
The Satspeed Interface converts GPS data to a pulse signal compatible with a radar sensor. It is suitable for any
instrument that cannot accept a GPS input directly, but which uses a pulse input for the forward speed signal.
Input: Any GPS receiver that outputs an NMEA VTG message via serial RS232, 9-way D connector.
1Hz –5Hz ; 4800, 9600 or 19200 baud,
Output: 128.16 pulses/metre (3.255 pulses/inch)
0.0078 metres/pulse (0.307 inches/pulse)
Limitation
This unit should not be fitted in situations where speed measurement <1km/hr is required, or there is consistent
poor quality GPS reception.
Installation
Connect to the system junction box / Terminator, Forward
Speed input terminals, as for a radar sensor i.e.
The 9-way D connector (pin 9) also provides a power supply
(Vss) for the GPS antenna/receiver, fed through the yellow
wire. The ‘RDS GPS-16 Satspeed’ antenna/receiver can use
this power supply.
Ensure that the GPS antenna/receiver is wired to accept a
voltage supply on pin 9 of the D connector. Connect the
yellow wire together with the red wire to a +V supply.
Wire Colour Function
Red +V (10 –30V supply)
Blue 0V
Green Signal
Yellow Antenna Power Supply
Pin Out Function
1-
2Rx
3Tx
4-
50V
6-
7-
8-
9Vss (10 –30V)

KIT -P/SATSPEED
GPS Speed Interface
Installation, Calibration and Operation
Doc. No. S/DC/500-10-592 : Issue 2 : 28/8/09 Page 2-UK592200.DOC
Calibration
Most instruments will require a Speed Sensor Factor (‘SSF’) of 0.0078 (metres/pulse) as for a TGSS radar
sensor.
Depending on the instrument and software, this will either be a simple preset option for a Radar Sensor, or
otherwise you may need to manually programme the factor. If unsure how to programme the factor, please refer
to the calibration manual for the instrument in question.
NOTE 1: For accuracy, some instruments with 4-digit displays are best programmed with the factor in inches i.e 0.307
(inches/pulse).
NOTE 2: If the speed reading is found to be half what it should be, the likely reason is because certain (earlier
specification) instruments require a SSF of 0.0156 (metres per 2pulses) for a radar sensor.
Operation
The unit will automatically find the baud rate and depending on GPS reception status, provide a forward speed
signal on power up.
NOTE: The forward speed reading will default to zero below 1km/hr.
Status LEDs
There are two LED’s indicating the unit’s status as follows,
LED 1 LED 2 Unit Status
Off Off No power
Fast Flash Off Power but no GPS signal (No forward speed reading)
Slow Flash Flash* Power + Standalone GPS (should result in forward speed reading)
On Flash* Power + Differential GPS (optimal performance)
* Flashes @ VTG message frequency e.g. 1Hz or 5Hz.