Curtis Instruments 1351, Руководство пользователя

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2 — INSTALLATION SPECIFICATIONS AND WIRING
Curtis Model 1351 – December 2018
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pg. 26
Sawtooth Position Transducer
The sawtooth transducer has two analog signals that ramp up as its shaft rotates through 360 degrees.
As illustrated below, the signals are offset by 180 degrees. Unlike the sine/cosine sensor, each signal
provides an absolute indication of position, thus requiring a different set of setup parameters. The
signal voltage range must be set and the voltage that represents 0 degrees is required. If the analog
signals go outside the specified ranges for >60mS, a fault is declares. Also, if the position calculated
using the channel A is outside a tolerance parameter compared to channel B for >60mS, a fault will
be declared. The tolerances must be maintained throughout the application’s operating conditions,
including voltage and temperature, along with speed and torque ranges when applied to a motor.
As illustrated in the sawtooth waveform diagram, connect the sensor with one waveform cycle per
mechanical revolution. Channels for A and B are parameter selectable for direction—A before B or
B before A.
An example application is tracking linear-travel and position such as fork-reach where one revelation
covers the range from retracted to full extend. Another is for steering angle where one steering-wheel
rotation equates to one cycle (360°) of the sawtooth waveform(s).
Table 15 Sawtooth transducer
Signal Name Pin
Operating Voltage
Signal Range (peak to peak)
Max. Frequency
Input
Impedance
ENC 1A (Analog 4) / B 15
0 – 10 (min – max)
0 – 10.0 V
200 Hz > 115 kΩ
ENC 1B (Analog 3) / A 14
ENC 2A (Analog 2) / B 2
ENC 2B (Analog 1) / A 1
A B
0
1
2
3
4
5
-225-180-135 -90 -45 0 45 90 135 180 225
Vo
lts
[
V
]
Position [
°
]
Sawtooth Waveform