PNI CompassPoint Prime - Manual (Page 13)

Prime User Manual r08 Page 7
The Prime Interface Kit includes the PNI 45 cm (18”) custom pigtailed cable (see Figure
3-2). One end of the cable mates with the Prime’s 9 pin Molex connector while the other end
is not connectorized and has 9 wires accessible. These wires are intended to mate with the
user’s system. The cable’s wires are color coded as indicated in Table 4-1.
The Prime Evaluation Kit includes the same PNI pigtailed cable as provided in the Interface
Kit, plus a 1.8 m (6’) custom dual-connectorized cable. This cable incorporates the Molex
51146-0900 connector on one end that mates to the Prime and a 9-pin sub-D connector on the
other end to mate with a computer’s serial port. This cable primarily is intended for basic
evaluation of the Prime with a computer.
4.2 Mechanical Installation
The Prime’s wide dynamic range and sophisticated calibration algorithms allow it to operate
in many environments. For optimal performance however, you should mount the Prime with
the following considerations in mind:
4.2.1 Operate with
in sensors’ useable regime
The Prime can be field calibrated to correct for large static magnetic fields created by the
host system. However, each axis of the Prime has a maximum useable range of ±100 µT.
If the total field exceeds this value for any axis the Prime may not give accurate heading
information. When mounting the Prime, consider the effect of any sources of magnetic
fields in the host environment that, when added to the earth’s field, may take the sensors
out of their linear regime. For example, distortions can be caused by large masses of
ferrous metals such as transformers and vehicle chassis, large electric currents, permanent
magnets contained within electric motors, and so on.
4.2.2 Locate away from changing magnetic fields
It is not possible to calibrate for changing magnetic anomalies. Thus, for greatest
accuracy, keep the Prime away from sources of local magnetic distortion that will change
with time, such as electrical equipment that will be turned on and off, or ferrous bodies
that will move. Make sure the Prime is not mounted close to cargo or payload areas that
may be loaded with large sources of local magnetic fields.