Manual

SF11 Laser altimeter
Product manual
j: Alarm switching distance (1.00 m … 120.00!m)
The distance at which the alarm output switches can be set by selecting menu item <j>. This value may also be changed using the
serial port and I2C command set.
k: Alarm voltage range (0.00 V … 2.048 V or 0.00 V … 3.30 V)
Select the logic level output voltage of the alarm signal using menu item <k>. This provides compatibility with different host
controllers. This value may also be changed using the serial port and I2C command set.
l: Alarm hysteresis (0.00 m … 5.00 m)
The alarm hysteresis stabilises the alarm output when slow moving targets remain near the switching distance for some time. Under
these conditions the alarm may switch many times in succession which may cause problems for the host controller. The hysteresis
moves the set point distance slightly to prevent this from happening. Hysteresis values are symmetrical so a value of 0.3 meters will
decrease the switching distance by 0.3 meters when the ground is far away and increase the switching distance by 0.3 meters when
the ground is close.!The alarm hysteresis can also be changed using the serial port and I2C command set.
m: Show or hide the filter menu
Menu item <m> is used to expand or hide the numerical filter menu. The settings available in this menu relate to providing smoothed
data to all the output ports and rejecting momentary changes in altitude caused by trees, fences, lost signals and out of range
conditions.
n: Output on lost signal (130.00 m | hold last result)
Menu item <n> is used to select the response to a lost signal condition. Either the result is shown as an out-of-range distance or the
last result is kept. This setting can also be changed using the serial port or I2C command set.
Item
HMI
Type
Serial
I2C
Analog range / alarm set point
menu item <j>
56.78 m
read
?OD<CR><LF>
.write(12) .read(a,b)
?OD 56.78<CR><LF>
distance range = (a*256+b)/100
write
#OD,56.78<CR><LF>
.write(13,a,b)
#OD,56.78 56.78<CR><LF>
a = (byte)(range*100 >> 8)
b = (byte)(range*100 & 0xff)
Item
HMI
Type
Serial
I2C
Analog voltage range
menu item <k>
0.00 V ... 2.048 V
read
?OV<CR><LF>
.write(14) .read(a,b)
?OV 2.048<CR><LF>
voltage range = (a*256+b)/100
write
#OV,0<CR><LF>
.write(15,a)
#OV,0 0<CR><LF>
a = 0 or 1
Item
HMI
Type
Serial
I2C
Alarm hysteresis
menu item <l>
0.03 m
read
?OH<CR><LF>
.write(18) .read(a,b)
?OH 0.03<CR><LF>
hysteresis = (a*256+b)/100
write
#OH,0.03<CR><LF>
.write(19,a,b)
#OH,0.03 0.03<CR><LF>
a = (byte)(hysteresis*100 >> 8)
b = (byte)(hysteresis*100 & 0xff)
Item
HMI
Type
Serial
I2C
Output on lost signal
menu item <n>
last ... 130 m
read
?FL<CR><LF>
.write(20) .read(a)
?FL 0<CR><LF>
output = a
write
#FL,0<CR><LF>
.write(21, a)
#FL,0 0<CR><LF>
a = 0 or 1
SF11 Laser altimeter - Product manual - Revision 9 | of | © LightWare Optoelectronics (Pty) Ltd, 2019 | www.lightware.co.za 13 20