Motorola M12 Oncore User's Guide download pdf (Page 51)

Chapter 3 - Receiver Descriptions

between 0 to 50 ms after a measurement epoch. For the Position/Status/Data Message, the

time output in the message reflects the best estimate of the most recent measurement epoch. A

simple timing diagram is shown in figure 3.8.

1PPS Cable Delay Correction and 1PPS Offset (M12+ Timing Receiver Only)

Users can compensate for antenna cable length with the 1PPS Cable Delay Command (@@Az).

The 1PPS can also be positioned anywhere in the one second window using the 1PPS Offset

command (@@Ay). The rising edge of the 1PPS is placed so that it corresponds to the time

indicated by the following equation:

1PPS rising edge time = top of second -1PPS cable delay + 1PPS offset

Consider the following example:

True Top of second = 10.000000000 s

1PPS cable delay correction = 0.000654321 s

1PPS offset = 0.100000000 s

1PPS rising edge time = 10.099345679 s

The rising edge of the 1PPS signal is adjusted so that it occurs corresponding to the fractional

part of time equal to the total above. The fractional part of time is measured relative to UTC or

GPS time depending on the setting of the Time Mode.

OPERATIONAL CONSIDERATIONS

When powered on, the M12+ Oncore Receiver automatically acquires and tracks satellites;

measures the pseudorange and phase data from each of up to twelve satellites; decodes and

collects satellite broadcast data; computes the receiver's position, velocity, and time; and outputs

the results according to the current I/O configuration selected by the user.

Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05

1 2 ... 46 47 48 49 50 51 52 53 54 55 56 ... 221 222

No comments

Motorola M12 Oncore User's Guide Page 51