Airmar NMEA 2000® Depth, Датчики - Manual (Page 15)

DST200 User Manual revision 1.000
Proprietary and Confidential
13
Each time this PGN is transmitted, the interval timer (used for field 5) is reset to 0.
The pulse frequency for a given interval can be calculated by dividing field 6 (number of pulses) by field 5 (duration of interval in seconds). Assuming a steady-state speed, the
error in this calculation will be:
Hz
field5
1
±
Therefore, at very low speeds, it will be necessary to use long intervals in order to collect enough pulses to achieve the required accuracy. Alternatively, the data from fields 5 and
6 may be accumulated over several successive transmissions of this PGN (assuming a steady-state speed over the entire measurement span).
The following transmitted PGNs are linked by their SID fields: PGN 128259 and Proprietary PGN 65409.
See also the proprietary transmitted Calibrate Speed PGN 126720-41.