HEIDENHAIN ND 287 User Manual - Manual (Page 72)

72
II Installation, specifications
II – 2 Installation Set
u
p
Incremental linear encoder
 For linear encoders, cursor to the SIGNAL PERIOD field and toggle
the COARSER or FINER soft key to select a predefined encoder
signal period, or type in the exact signal period (in µm) desired (see
"Encoder parameters" on page 98).
 In the REFERENCE MARK field, toggle the REF MARK soft key to
select whether the encoder has no reference signal (NONE), a
single reference mark (SINGLE) or distance-coded reference marks
(CODED/...). For distance-coded reference marks, select the
spacing (500, 1000, 2000 or 5000 signal periods).
 In the EXTERNAL REF field, press the ON/OFF soft key to select
whether pin 25 at connection X41 is active or inactive. This pin can
be used to activate or deactivate the reference mode. The
respective current status is changed.
 In the COUNT DIRECTION field, select the count direction by
pressing the POSITIVE/ NEGATIVE soft key. If the encoder's count
direction matches the user's traverse direction, select POSITIVE. If
the directions do not match, select NEGATIVE.
 In the ERROR MONITOR field, select whether the ND will monitor
and display encoder counting and signal errors by pressing the
ERROR soft key. In the ERROR MONITOR field, you can select OFF,
FREQUENCY, CONTAMINATION or FRQ.+CONTAMINATION.
When an error message occurs, press the C key to acknowledge it.
Counting errors
are caused by contamination or excessive
frequency:
 Contamination : The signal to the encoder falls below a set limit.
 Frequency errors : The signal frequency exceeds the set limit.
Fig. II.10 Incremental linear encoder form
Fig. II.11 Incremental linear encoder form
Fig. II.12 Incremental linear encoder form
If you set the ERROR MONITOR field to OFF, the ND 287
will ignore encoder errors.