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SF30
SF30
Accelerated rangefinder
Product manual
8. The alarm interface
The alarm output is a 0 V to 3.3 V signal that becomes active low when the distance reading falls below a preset distance. The
distance value used to calculate the alarm state is taken from the analog port settings. However, the maximum range selection of
the analog port does not limit the operational range of the alarm.
Figure 9 :: Alarm interface connections
The “7: Alarm activation distance” setting determines the distance below which the alarm signal becomes active (low). There is
hysteresis on this set point equal to the resolution of the reading or 0.06 m, whichever is the larger.
The “8: Alarm latch” selection turns on or off a latching function that keeps the alarm in an active state until a reset command is
received. The reset can be from the serial port (#X) or from the keyboard if the USB cable is connected by pressing the
<X>
key.
9. USB port settings
The “9: USB port update rate” setting allows the user to adjust the update rate of the distance readings to make them more
readable in the Terminal window.
The USB port also has a number of “hot keys” that allow for immediate control of certain functions, as described below:
•
Press
<X>
on the keyboard to clear the alarm signal latch.
•
Press
<Y>
on the keyboard to start the laser firing.
•
Press
<N>
on the keyboard to stop the laser from firing.
Setting
Values
Description
7: Alarm activation distance
1.5 m ... 254 m
Sets the distance below which the alarm signal will change to a low state. There
is hysteresis on this setting equal to the “2: Resolution / Smoothing filter”
setting or 0.06 m whichever is the greater value.
8: Alarm latch
Off <-> Active
Enables the alarm signal latch. This keeps the alarm in the active low state after
an alarm event until it is cleared by sending the “#X” command to the serial
port or by pressing
<X>
on the keyboard.
Setting
Values
Description
9: USB port update rate
1 ... 1144 / sec
Sets the rate at which new results are output from the USB port when it is selected
using “1. Active data port”.
The maximum value is limited to 1144 readings per second.
Only whole number fractions of 18316 will give an exact match between the
entered and actual values.
SF30 Accelerated laser rangefinder - Product Manual - Revision 5
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© LightWare Optoelectronics (Pty) Ltd, 2015
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