HEIDENHAIN
Working with the position
display unit
Actual value and input display
(7-segment LED,
9 decades and sign)
• Select datum
• Page backward in
parameter list
ND 286
• Confirm entry value
• Set display to value from
P79 (P80!)
Numeric keypad
789
456
REF21 SET
=
<>
MIN ACTL MAX DIFF
START PRINT
in.
MOD
HEIDENHAIN
Status display
• Switch display to:
MIN / MAX / DIFF / ACTL / START / PRINT
• Go to parameter list after switch-on
• Page forward in parameter list
Indicator Meaning
REF If the decimal points have stopped blinking:
Reference mark was crossed over — datum points are now stored
in nonvolatile memory.
Blinking: Waiting for operator to press ENT or CL.
in. Position values displayed in inches.
1 / 2 Datum 1 / Datum 2 currently active.
PRINT Blinking: Waiting for ENT for data output.
SET Blinking: Waiting for operator to confirm entry.
• Clear entry
• Reset to zero (P80!)
• CL plus MOD:
parameter list
• CL plus 2-digit number: select parameter
• Clear parameter entry
and show parameter
number
123
.
0
–CL
• Algebraic
sign
• Decrease
parameter
value
• Decimal point
• Increase parameter value
< / = / > Sorting mode: Measured value less than lower limit / within
tolerances / greater than upper limit.
MIN / MAX Measuring series: Minimum / Maximum /
DIFF / ACTL largest difference (MAX–MIN) / current measured value.
Blinking: Waiting for confirmation of value to be displayed.
START Measuring series in progress.
Blinking: Waiting for start signal for measuring series.
The ND 286 position display unit is designed for use with HEIDENHAIN linear or
rotary encoders with square-wave output signals. These encoders have one or more
reference marks, which may also be
When a reference mark is crossed over, it generates a signal identifying that position
as a reference point. After switch-on, simply crossing over the reference mark
restores the relationship between axis positions and display values as it was last
defined by datum setting.
With distance-coded reference marks, a maximum traverse of only 20 mm suffices to
re-establish the datum.
distance-coded
.
Switch-On
0 ➤1
Ent...CL
5 , 6 9 7
If you do not wish reference mark evaluation, press CL instead of ENT.
Turn on the power (switch located on rear panel).
• Display shows .
• REF indicator blinks.
• Data interface shows ERROR 07
Switch on reference mark evaluation.
• Display shows the value last assigned to the
reference mark position.
• REF indicator glows.
• Decimal point blinks.
Cross over reference mark.
Move the axis until the display becomes active and the
decimal point no longer blinks.
Setting the Datum
The datum setting procedure assigns a display value to a specific axis position.
The ND 286 allows you to set two independent datums.
Select datum 1 or 2.
Enter a value, such as 40.
4 0
Confirm entered value.
You can switch from one datum to the other at any time.
Use datum 2 when you want to display incremental values.
Measuring Series
The ND 282 display unit can calculate and display one of the following values from a
measuring series:
Smallest value (MIN), largest value (MAX), difference between largest and smallest
value (DIFF), last value measured (ACTL)
A new value is captured every 550 µs during a measuring series.
To start a measuring series:
➤ Press the MOD key repeatedly until the desired indicator starts blinking.
Example: to display the largest value, press MOD until MAX blinks.
➤ Confirm your selection by pressing ENT.
➤ Press MOD repeatedly until the START indicator blinks.
➤ Start the measuring series by pressing ENT.
You can switch between MIN, MAX, DIFF and ACTL at any time:
➤ Press MOD until the desired indicator blinks, then confirm with ENT. Or
➤ Use operating parameter P21 (see list of operating parameters).
Note:
When the switching input for remote control of the measuring series is active (pin 6
of D-sub connection EXT), you cannot switch over the display as described here.
To abort a measuring series and restart:
➤ Press MOD until START blinks, then confirm with ENT.
To end a measuring series:
➤ Press MOD until the glowing indicator blinks, then confirm with ENT.
It is also possible to start a measuring series and switch over the display with a
switching input over the D-sub connection EXT (see that section).
Sorting and Tolerance Check Mode
In this mode, the display value is compared with an upper and a lower limit value.
Status indicators and the switching outputs at the D-sub connection EXT indicate
whether the display value is less than the lower limit, greater than the upper limit, or
between the two limit values.
Indicator Meaning
= Measured value is between the limit values
< Measured value is less than the lower limit value
> Measured value is greater than the upper limit value
Operating parameters for the sorting mode:
• P17: sorting on / off, P18, P19: limit values
Distance-to-go Mode
The standard setting for the display unit is to show the encoder position value.
Code number 246 582 provides access to the distance-to-go mode.
“Traverse to zero” with distance-to-go display
➤ Select datum 2.
➤ Enter the nominal position.
➤ Move the axis to the display value zero.
In distance-to-go mode the trigger outputs A1 (Pin 15) and A2 (Pin 16) change their
meaning: they become symmetrical to the display value zero.