Chapter 3
Connecting the UMI-7774/7772 to Drives and Other Devices
National Instruments UMI-7774/7772 User Manual
3-18
ni.com
Encoder
The UMI-7774/7772 works only with encoders that have differential line
or complementary driver outputs. Refer to Figure 3-13 for an illustration of
the encoder input interface circuit. The UMI-7774/7772 supports
differential inputs for Phase A, Phase B, and Index signals.
Figure 3-13.
UMI-7774/7772 Encoder Input Interface Circuit
Note
The UMI-7774/7772 does
not
support single-ended encoders.
The differential encoder signals are converted to single-ended signals by a
differential-to-single-ended converter on the UMI-7774/7772 and are then
passed through to the National Instruments motion controller.
You can accommodate encoders with various phase relationships by
swapping the signals and/or connecting them to the inverting inputs
as required by the application. A +5 V output, generated by the
UMI-7774/7772 internal power supply, is also available on the connector
for powering encoders. Figure 3-14 shows the default encoder phasing for
National Instruments motion controllers You can configure this phasing
using Measurement and Automation Explorer (MAX) or NI-Motion driver
software.
+
–
120
Ω
Phase A
Phase A
Phase A
+
–
120
Ω
Phase B
Phase B
Phase B
+
–
120
Ω
Index
Index
UMI-7774/7772
Index
