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RS-Helios-16P User Manual
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enough to hit multiple objects, it will produce multiple reflections.
RS-Helios-16P analyzes the received multiple returns, and can be set to only report the strongest
return, first return or the last return each time, or the strongest and last return, the strongest and
first return, the first and the last return at the same time, depending on the laser return mode
settings. If it is set to the strongest return mode, only the value of strongest return will be reported.
Similarly, if is set to the last return mode, only the value of the last return will be reported.
Note :
1. The sensor records two returns only when the distance between two objects is 1 meter or more.
2. When a laser pulse hits only one object, there is only the strongest return.
3. When a laser pulse hits two solid walls or other objects at two different distances, two returns will be produced.
In this case, there are two situations:
(1)
When the strongest return is not the last return, the strongest and last return will be reported;
(2) When the strongest return is the last return, the strongest return and the second strongest return will be
reported.
5.4.2 Return Mode Flag
The RS-Helios-16P is set in the Strongest Return mode at factory by default. If you need to change
this settings, please refer to Appendix A.2 in this user manual for instructions. The 300th byte in a
DIFOP packet is the flag of return mode, which corresponds to the following:
Table 6 Return Mode Flag
Flag
Return Mode
00 Dual Return
04 Strongest Return
05 Last Return
06 First return
5.5 Phase Locking
The phase locking feature, when a PPS pulse signal is triggered, askes the RS-Helios-16P to rotate
to a specific angle to fire laser pulses. When multiple RS-Helios-16P sensors are used at the same
time, the relative rotation angle between them is kept unchanged. The normal phase locking
requires the normal and stable PPS pulse triggering signal.
Figure 7 shows the RS-Helios-16P set with different phases. The red arrows indicate the firing angle
of the sensor’s laser at the moment it receives the rising edge of the PPS signal. In the cases below:
0 degrees, 135 degrees, and 270 degrees respectively.