Emerson SI-Universal User Manual page 10

NOTE
The absolute maximum input frequency for any SC, SinCos encoder used with the SI-Universal
Encoder option module is 500 kHz.
3.4.2 SinCos encoder feedback signals
For the SinCos encoder to be compatible with the SI-Universal Encoder option module, the output
signals from the encoder must be a 1 V peak to peak differential voltage (across sinref to sin and
cosref to cos).
Figure 3-2 Stegmann SinCos encoder feedback signals
SIN
0.5 Vdc
REFSIN,
REFCOS
2.5Vdc
.
0.5 Vdc
COS
Stegmann
Stegmann encoders typically have a 2.5 Vdc offset. The sinref and cosref are a flat DC level at 2.5
Vdc and the cos and sin signals have a 1 V peak to peak waveform biased at 2.5 Vdc.
The result is a 1 V peak to peak differential voltage as show in Figure 3-2.
Heidenhain
The Heidenhain Sin and Cos signals with respect to zero volts are offset at 2.5 Vdc as shown in
Figure 3-3.
The feedback signals which are seen by The SI-Universal Encoder module are the differential
signals Sin - Sin\ and Cos - Cos\ as in Figure 3-3, these being 90° phase shifted and at 1 Vdc peak
to peak.
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SI-Universal Encoder User Guide
Issue: 2