Hirschmann PAT DS 85/0002 - Page 16

Service Manual DS 85
© Hirschmann Rev.G 10/05/15 190166_G.DOCXG
10
Terminal X20
1
+ (~ 4.8V)
3
Signal
5
- (~ 0.2V)
Verify that the sensor is being supplied with about 4.7V by measuring between pin 5 (-) and Pin 1 (+)
of terminal X20. If the voltage is outside of a range of 4.5 to 5 V, the converter board might be
defective. Unplug length sensor and measure again. If the voltage is still off, exchange converter
board. If unplugging the length sensor made the voltage return into the acceptable range, exchange
length sensor. If the voltage is correct continue:
The length sensor returns a voltage between 0.16V at 0 turns of the length pot (= fully retracted) and
4.84V at 10 turns. How many turns you get at full extension depends on the gear ratio, the boom
length, the length cable used and the spooling pattern, so we cannot provide a standard table for it.
What we can give you for trouble-shooting, however is the following table that shows the expected
output voltage (measured between X20-5 and X20-3 Signal) for each complete turn of the length
potentiometer. Note that this does not sync to the number of turns of the cable reel, though:
Length Sensor Signal on Pin 3
Potentiometer
Turns
Voltage X20-5
to X20-3
Voltage GND to X20-3
0
0.00
0.16
1
0.46
0.62
2
0.93
1.09
3
1.40
1.56
4
1.87
2.03
5
2.34
2.50
6
2.81
2.97
7
3.28
3.44
8
3.75
3.91
9
4.22
4.38
10
4.68
4.84
Note: Actual voltages will vary slightly.