8.4.4
Digital Field Plate / GMR
The switching thresholds of the converter input IN8 are 5.4 V for active-low signals and
5.9 V for active-high signals. Therefore the switching thresholds of the used sensor
must be adapted to the input by offsetting the middle voltage.
[*]
The resistors R
1
and R
2
depend on the used sensor.
Sample calculation of the resistors R
1
and R
2
The resistance is calculated by means of the spindle data.
Specifications taken from the data sheet of the spindle manufacturer:
▶
Sensor off: 4 mA (signal is not available)
▶
Sensor on: 8 mA (signal is available)
▶
Voltage V: 3 V (amplitude with 24 V supply and a resistance (R
2
) of 680 Ω)
The resistance Rinternal (4.4 kΩ) results from the circuit topology and must be
included in the calculation.
The spindle data make the following voltage levels at the input:
I
´
1
1 R
2
ext
1 R
int
+
1
1 680
W
1 4400
W
+
= 4 mA
´
= 2.36 V
Sensor off:
(
(
(
(
I
´
1
1 R
2
ext
1 R
int
+
1
1 680
W
1 4400
W
+
= 8 mA
´
= 4.71 V
Sensor on:
(
(
(
(
Middle voltage of the sensor: (4.71 V + 2.36 V) / 2 = 3.54 V
Middle voltage of the input IN8 at the SD2S: (5.9 V + 5.4 V) / 2 = 5.65 V
The voltage level must be increased according to the difference between the middle
voltages. This is done by a boost voltage at R
1
.
Boost voltage R
1
: 5.65 V - 3.54 V = 2.11 V
Resistance value R
1
: (24 V / 2.11 V) × 588 Ω = 6.688 kΩ → 6.8 kΩ
(588 Ω results from the resistances of R
2
external and Rinternal.)
If you use other sensors, please pay attention to the input switching thresh‐
olds of the sensor and the data sheet provided by the spindle manufacturer.
W
Connection Examples
Drive System SD2S - Hardware Description 0362X49xy / 0362129xy
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8
Summary of Contents for SD2S 0362249xy
Page 4: ...Chapter Overview W 4 Drive System SD2S Hardware Description 0362X49xy 0362129xy...
Page 8: ...Content W 8 Drive System SD2S Hardware Description 0362X49xy 0362129xy...
Page 12: ...About this Manual W 12 Drive System SD2S Hardware Description 0362X49xy 0362129xy 1...
Page 16: ...General Information W 16 Drive System SD2S Hardware Description 0362X49xy 0362129xy 2...
Page 30: ...Drive Amplifier SD2S W 30 Drive System SD2S Hardware Description 0362X49xy 0362129xy 5...
Page 54: ...Connector Pin Assignment W 54 Drive System SD2S Hardware Description 0362X49xy 0362129xy 7...
Page 80: ...Setup W 80 Drive System SD2S Hardware Description 0362X49xy 0362129xy 9...
