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Speeder X1 and X2 Configuration and API Guide
Page 19/36
measurement output rate for raw distance data is (Pulse rate)/8 and (Speed pulse
rate)/16. Suggested values are 2000 for pulse rate and 4000 for speed pulse rate. With
these suggested values output rate will be 250 measurements/second for entire vehicle
detection.
First data byte
MSB
LSB
No.
7
6
5
4
3
2
1
0
Value
Note
1
h80
Start of the data bytes
x
h40
Error bit
0 = Correct distance measurement
1 = Error in distance measurement
x
x
x
x
x
x
h00
to
h3F
Distance Value MSB or Error code
- Distance bits 12 to 7
- Error Code if bit 6 = 1
Second data byte
MSB
LSB
No.
7
6
5
4
3
2
1
0
Value
Note
0
x
x
x
x
x
x
x
h00
to
h7F
Distance Value LSB
- Distance bits 6 to 0 [cm]
-
‘E’ if error (h45)
Third data byte (only if bit 3 of Control Byte 2 Enabled)
MSB
LSB
No.
7
6
5
4
3
2
1
0
Value
Note
0
x
x
x
x
x
x
x
h00
to
h7F
Signal Amplitude
- Amplitude divided by 16
-
‘R’ if error (h52)
Distance = 128 x Distance Value of First Data Byte + second byte [cm]
4.1.4 Snow accumulation measurement
Speeder is able to measure snow accumulation on the road while operating in speed
measurement mode. Accumulation is switched on with Control Byte 5
bit 3 “Measure
Snow Fall”. Ground level (distance to the ground) is set to word parameter 48 “Ground
distance” in centimetres. Running “Automatic setting of measurement window” (Chapter
4.3) sets ground distance value in case Speeder is able to measure on to the ground.
Furthermore this value can be set manually when the distance is known.
