SICK NAV310, Руководство по эксплуатации

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Product description
24
© SICK AG · Germany · All rights reserved · Subject to change without notice
8016535/1D2F/2022-11-14
Operating instructions
NAV310 Laser positioning sensor
Chapter 3
3.7.3 Digital output
The NAV310 has a digital output that is used for the synchronisation of the internal clock
on the NAV310 and the vehicle computer’s clock. The output supplies an at least 10 ms
long pulse depending on the synchronisation method (see section
3.7.4 on page 24 ). The
pulse is output dependent on the synchronisation method.
Fig. 10: Pulse for synchronisation
3.7.4 Synchronisation of the clock in the AGV and the clock in the NAV310
For precise control, it is necessary to synchronise as accurately as possible the contour data
from the NAV310 and the calculations on the vehicle computer.
The internal time stamp in the
NAV310
is added to the measured data from the NAV310.
The internal time stamp in the NAV310 is a 32-bit counter that counts up by 1 every 1 ms.
To synchronise the internal time in the NAV310 with the system time in the vehicle’s control
system, the NAV310 provides three options.
1. via telegram
The vehicle computer requests the internal time from the NAV310 using a telegram.
The NAV310 writes its internal time in a telegram and sends it to the vehicle computer.
However, there can be a delay of up to 3 ms on sending the data, as a result there is
certain amount of inaccuracy.
2. via telegram „Timer Read“
The vehicle computer request the internal time from the NAV310 using a telegram. The
hardware output supplies a pulse of at least 10 ms in length
fig. 10 as soon as the in-
ternal time stamp is written to the telegram. When the telegram is subsequently re-
ceived by the vehicle computer, the vehicle computer can add to the time in this
telegram the delta between the pulse and the reception. As a result the AGV can deter-
mine the actual time in the NAV310.
3. Via Index (using the hardware output)
Fig. 11: Pulse on the head position
NAV310 sends a signal depending on the position of the scanner head. This signal is
used to synchronize scans with the position of a swivel device for 3D measurements.
Important Program the vehicle computer so that it responds to the front edge of the output pulse
min. 10 ms