The pulse output from the SPEEDBOX can be set to output either the internally calculated distance pulse, or the once per second GPS timepulse.
Distance pulse output
Assuming that the pulse output is set to work based on distance rather than on GPS timepulse, the pulse output can be turned on or off. If the pulse output is not required and the analogue outputs are being used then it is recommended to turn the pulse off, in order to minimise noise adjacent to the analogue outputs.
The number of pulses per metre can be set between 1 and 400.
Pulse type can be either a fixed width, in which case the high time is specified in the box below, or a 50% duty cycle in which case the high time is a function of the vehicle speed.
Whatever type of pulse is set up, the maximum speed which can be output by the system is shown.
NOTE: If using the pulse output with a triggered test, the accuracy will be greatest when using an external trigger input. If triggering based on speeds, distance errors equivalent to 50ms can be present in the pulse count, for analogue input triggered values errors of up to 10ms can be present.