2.3.1.3. Sine Wave Encoder [-CT1/-CT2/-CT4 Option]
The Sine Wave Encoder option provides higher positioning resolution by subdividing the fundamental
output period of the encoder into smaller increments. The amount of subdivision is specified by the
PrimaryEncoderMultiplicationFactor [A3200: EncoderMultiplicationFactor] parameter. Use Encoder
Tuning [A3200: Feedback Tuning] to adjust the value of the gain, offset, and phase balance controller
parameters to get the best performance. For more information, refer to the Help file.
High resolution or high-speed encoders can require increased bandwidth for correct operation. Use the
High Speed Mode of the PrimaryEncoderMultiplierSetup [A3200: EncoderMultiplierSetup] parameter to
enable the high bandwidth mode. Because this mode increases sensitivity to system noise, use it only if
necessary.
The XR3 with the -CT2 and -CT4 options can generate emulated encoder signals. These signals can be
output on the AUX ENCODER connector, the HSOUT (High-Speed Output) connector, or used internally
by the PSO. Refer to the EncoderDivider and PrimaryEmulatedQuadratureDivider
[A3200: EmulatedQuadratureDivider] parameters and the encoder output functions [A3200:
ENCODER OUT command] in the Help file for more information.
You cannot use a sine wave encoder with the -CT1 multiplier option as an input to the PSO. The -CT1
option does not generate emulated quadrature signals.
For the highest performance, use twisted pair double-shielded cable with the inner shield connected to
signal common and the outer shield connected to frame ground. Do not join the inner and outer shields
in the cable.
Table 2-12:
Sine Wave Encoder Specifications
Specification
Value
Primary
Auxiliary
Input Frequency (max)
450 kHz, 2 MHz
Input Amplitude
(1)
0.6 to 1.75 Vpk-pk
Interpolation Factor (max)
-CT1
16,384
N/A
-CT2
65,536
N/A
-CT4
65,536
65,536
-CT2/-CT4 Primary Encoder Channel
Interpolation Latency
800 nsec (analog input to quadrature output)
Input Common Mode
1.5 to 3.5 VDC
(1) Measured as SIN(+) - SIN(-) or COS(+) - COS(-)
Figure 2-13:
Sine Wave Encoder Phasing Reference Diagram
2.3.1.3. Sine Wave Encoder [-CT1/-CT2/-CT4 Option]
XR3 Hardware Manual
44
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