F
PowerPak II Enclosure
80
GPS/GLONASS Receiver User Manual Rev 1
F.3.3.2.1 RS232C Y-type Null-Modem Cable (NovAtel part number 60715062)
This serial data cable supplied with the PowerPak II provides a means of communications with a personal
computer. As shown in the following figure, the cable is equipped with a 9-pin connector at the PowerPak II end
which can be plugged into either COM1 or COM2. At the computer end, both a 9-pin and a 25-pin connector are
provided to accommodate most serial (RS232C) communication ports.
Reference
Description
1
DE9S socket
2
DB25S socket
F.4 OTHER OPTIONAL POWERPAK II ACCESSORIES
F.4.1 USER-SUPPLIED EXTERNAL OSCILLATOR
For certain applications requiring greater precision than what is possible using the 20 MHz on-board, voltage-
controlled temperature-compensated crystal oscillator (VCTCXO), you may wish to connect the GPSCard to an
external, high-stability oscillator. This is only possible with a MiLLennium-GLONASS GPSCard on its own or in
a PowerPak II enclosure, not if the MiLLennium-GLONASS GPSCard is in a ProPak II enclosure. Refer to section
F.4.1.1 for instructions to connect the MiLLennium-GLONASS GPSCard or the PowerPak II to an External
Oscillator.
The external oscillator can be either 5 MHz or 10 MHz. The MiLLennium-GLONASS GPSCard has built-in clock
models for OCXO, rubidium and cesium oscillators, but you can also set custom clock model parameters for other
types of oscillators. Two commands relate to external oscillator operation; EXTERNALCLOCK and
EXTERNALCLOCK FREQUENCY.
If there is no external oscillator, you should use the EXTERNALCLOCK DISABLE command.
EXTERNALCLOCK determines if the GPSCard uses its own internal temperature-compensated crystal oscillator,
or an external oscillator as a frequency reference. It also sets which clock model is used for external oscillators.
NOTE:
The EXTERNALCLOCK DISABLE command forces the GPSCard to use the internal oscillator,
whether there is an external oscillator connected or not. Do not use the EXTERNALCLOCK OCXO,
CESIUM, RUBIDIUM or CUSTOM command if no external oscillator is connected.
Command
Reference Oscillator
Clock Model
EXTERNALCLOCK DISABLE
internal
-
EXTERNALCLOCK OCXO
external
OCXO
EXTERNALCLOCK CESIUM
external
cesium
EXTERNALCLOCK RUBIDIUM
external
rubidium
EXTERNALCLOCK CUSTOM
external
user-defined parameters
1
1
2
