Npaq® Hardware Manual
Installation and Configuration
2.6.1.2. MXR Option (Analog Encoder Interface)
If the -MXR option (-MXR or -MXR2M) has been purchased, the standard encoder channel will accept a
differential analog encoder input signal. The interpolation factor is determined by the
EncoderMultiplicationFactor parameter and is software selectable (refer to the A3200 Help file
Table 2-15:
Analog Encoder Specifications
Specification
MXR
MXR2M
Input Frequency (max)
200 kHz
2 MHz
Input Amplitude
0.6 to 2.25 Vpk-Vpk
0.6 to 2.25 Vpk-Vpk
Interpolation Factor (software
selectable)
16,384
16,384
MXR Interpolation Latency
~ 3.25 µsec (analog input to
quadrature output)
~ 3.25 µsec (analog input to
quadrature output)
Refer to
for the MXR typical input circuitry.
The encoder interface pin assignment is indicated in
The gain, offset, and phase balance of the analog Sine and Cosine encoder input signals can all be adjusted
via controller parameters. Encoder signals should be adjusted using the Feedback Tuning tab of the Digital
Scope, which will automatically adjust the encoder parameters for optimum performance. See the
A3200 Help file for more information.
Figure 2-16:
Analog Encoder Phasing Reference Diagram (-MXR option)
N O T E :
The input amplitude is measured peak to peak for any encoder signal (sin, sin-n, cos, cos-n)
relative to signal common. These signals have a typical offset voltage of 2V to 2.5V.
48
Chapter 2
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