User`s manual

GFK-1742A C-1
Position Feedback Devices
There are four GE Fanuc
α
and
β
Series Digital serial encoder models that will function with the
DSM314:
Table C-1. Digital Serial Encoder Resolutions
8K (8,192 cts/rev) - No longer available on new motors
32K (32,768 cts / rev) - Standard on
β
Series motors
64K (65,536 cts/rev) - Standard on
α
Series motors
1000K (1,048,576 cts/rev) - Optional on
α
Series motors
Note
The older “A” or “C” Series million count serial encoder will not operate with
the DSM314. An error will be reported if this encoder is connected.
For position control purposes, by default, the DSM314 treats all encoders as 8192 counts/rev. The
additional resolution of 32K, 64K and 1000K encoders will still be used in the digital servo
velocity controller to provide smooth operation at low speeds. To use the increased position feed
back resolution, refer to the Tuning Parameter section of the Configuration Chapter.
Digital Serial Encoder Modes
The GE Fanuc Digital serial encoders can be operated in either
Incremental
mode or
Absolute
mode
.
The mode is configured using the Feedback Mode selection in the configuration software.
Proper operation of the
Absolute
mode requires an external battery pack that must be connected to
the servo amplifier. Refer to the appropriate amplifier manual for selection and installation of the
battery pack.
Incremental Encoder Mode Considerations
The digital serial encoder can be used as an incremental encoder returning 8192 counts per shaft
revolution, with no revolution counts retained through a power cycle. The equivalent of a
marker
pulse will occur once each motor shaft revolution. All Home Modes (Home Switch, Move+,
Move–) and
Set Position
%AQ commands reference the axis, and set the
Position Valid
%I bit
upon successful completion. The configured High Position Limit and Low Position Limit are
C
Appendix