HEIDENHAIN ND 281 B User Manual v.1
User’s Manual
Measured Value Displays
6/ 2000
Display of actual value and input
(9 decades with algebraic sign)
REF SET START PRINT inch
=
<>
21
MIN ACTL MAX DIFF
HEIDENHAIN
Status display with indicators
Numeric keypad
with decimal point
789
456
MOD
123
.
0
CL
2
Key Function
• Set datum
• Transfer input value
• Set display to value from P79 (P80!)
• Leave parameter list
• Select datum
• Page backwards in parameter list
MOD
• Select parameter after switch-on
• Page forward in parameter list
• Start series of measurements
• Switch display for measurement series
• Start measured value output “PRINT”
• Delete entry
• Set display to zero (P80!)
• CL plus MOD: select parameter list
• CL plus number: select parameter
• Delete parameter input and show
parameter number
• Algebraic sign
• Reduce parameter value
• Decimal point
• Increase parameter value
1)
Only in linear measurement mode.
Indicator Meaning
REF If the decimal point is also blinking:
Display is waiting for reference mark
traversing. If decimal point is not blinking:
Reference mark has been traversed—display
stores datum points in nonvolatile memory
Blinking: display is waiting for ENT or
CL to be depressed
inch Position values in inches
1)
1 / 2 Selected datum point
1)
PRINT "Linear measurement”
Blinking: Display is waiting for ENT to
be pressed for data output
“Angular measurement”
Measured value output with MOD key
SET Blinking: Display is waiting for input values
< / = / > Sorting and tolerance checking:
measured value smaller than lower limit /
within the limits / greater than upper limit
/
MAX / Series of measurements: Minimum /
MIN
maximum / greatest difference (MAX–MIN) /
current measured value
1)
DIFF / ACTL
Blinking: Confirm selection or deselect
function
START
1)
Series of measurements is running
Blinking: Display is waiting for signal to
start series of measurements
3
Items supplied with ND 281 B
ND 281 B Measured value display unit,
benchtop model
Encoder input
11 µAPP/1 V
Power cord 3 m (9.9 ft)
User's Manual ND 281B
Items Supplied
Adhesive plug-in feet For stacking ND 281B units
PP
This manual is for the ND 281 B measured value
display with the following software number or higher:
349 797-01
Id. Nr. 344 996-xx
The software number is indicated on a label on the
4
rear panel.
Contents
Working with the ND Display Units
Encoders 6
Reference Marks 7
Switch-On, Traversing the Reference Marks 8
Datum Setting 9
Finding Minimum and Maximum Values
Sorting and Tolerance Checking 13
Measured Value Output 14
Display Freeze 15
Error Messages 16
1)
10
Installation and Specifications
Rear Panel, Accessories 17
Mounting 19
Power Connection 20
Linear/Angular Measuring Modes 21
Operating Parameters 22
List of Operating Parameters 24
Linear Encoders 28
Angle Encoders 33
Nonlinear Axis Error Compensation 34
RS-232-C/V.24 Interface (X31) 38
Switching Inputs and Outputs EXT (X41) 43
Locking the Keypad 48
Displaying the Software Version 49
Distance-to-Go Mode 50
Specifications 51
Dimensions 52
Contents
1)
Only in linear measurement mode
5
Position Encoders
The ND 281 B display unit is designed for use with photoelectrical linear or angular encoders with sinusoidal signals:
primarily for HEIDENHAIN MT length gauges.
When shipped by HEIDENHAIN, the display units are set to the
linear measurement mode.
You can switch between the linear and angular modes by
Position Encoders
entering the code number 415263 (see “Linear/Angular
Measurement Modes”).
On the back of the display you will find two flange sockets for
connecting the encoder: X1 for encoders with 11 µA
dal current signals and X2 for 1 V
Before shipping, HEIDENHAIN activates the encoder connection X1 for 11 µA
P02 you can activate the encoder input that matches your
encoder (see “Operating Parameters”).
sinusoidal current signals. With parameter
PP
sinusoidal voltage signals.
PP
sinusoi-
PP
6
Reference Marks
The MT length gauges have one reference mark. The scales of
other photoelectric linear or angular encoders can contain one
reference mark or many
distance-coded
reference marks.
If there is an interruption of power, the relationship between the
position of the length gauge and the displayed position value is
lost. The reference marks on the position encoders and the REF
reference mark evaluation feature enable the display unit to
quickly reestablish this relationship again when the power is
restored.
When a reference mark is crossed over, a signal is generated
which identifies that position as a reference point. At the same
time, the display unit restores the relationship between length
gauge position and display values which you last defined by
setting the datum.
To restore the datum on scales with distance-coded reference
marks, you only need to traverse a maximum of 20 mm for
linear encoders, and 10° or 20° for angle encoders, depending
on the model.
Scale in Distance-coded
linear encoder reference marks
Reference Marks
Reference mark
Reference marks on linear encoders
7
Switch-On, Traversing the Reference Marks
REF Mode
➤➤
➤
➤➤
0
ENT...CL
5 , 6 9 7
Switch-On, Traversing the Reference Marks
For automation purposes, crossing over the reference marks
and the display ENT ... CL can be disabled with parameter P82.
Turn on the power.
1
(Switch located on rear panel.)
• ND 281 B appears for two seconds.
• ENT ... CL
• REF indicator is blinking.
Switch-on the reference mark evaluation
function.
• The position value that was last
assigned to the reference mark
position is displayed.
• REF indicator lights up.
• Decimal point is blinking.
Cross over the reference mark.
Move the plunger until the display starts
counting and the decimal point stops blink-
⇔
ing. The display is now ready for operation.
1)
appears.
Crossing over the reference marks automatically switches the
display to REF mode: The last assignment of display values to
length gauge positions is stored in nonvolatile memory.
1)
Press the CL key if you choose not to traverse the reference
marks. Note that, in this case, the relationship between
length gauge position and display value will be lost if the
power is interrupted or if the unit is switched off.
8
Datum Setting
The datum setting procedure assigns a display value to a
known position. With the ND 200 series, you can set two
separate datum points.
There are several ways to set the datum:
• Enter a numerical value, or
• Transfer a value from an operating parameter
(see P79, P80), or
• By external signal
Select datum 1 or 2.
Enter numerical value (here, 5).
5
You can switch between datums 1 and 2 as desired. Datum 2
can be used, for example, for working with incremental dimensions.
When you switch back to datum 1, the display unit resumes
display of the encoder's actual position.
SET blinks.
Confirm the entered numerical value.
Z
?
?
?
?
?
Without datum setting: unknown assignment of measured
values to positions
Datum Setting
After datum setting: Assignment of measured values to
positions
9
Finding Minimum and Maximum Values from a
Series of Measurements
After a series of measurements has been started, the display
transfers the first measured value to the memory for minimum
and maximum values. Every 0.55 ms, the display compares the
current measured value with the memory contents: A new
value is stored if it is greater than the stored maximum value or
smaller than the stored minimum value. At the same time, the
display calculates and stores the difference DIFF between the
current MIN and MAX values.
Display Meaning
MIN Minimum value from the series of measurements
MAX Maximum value from the series of measurements
DIFF Difference MAX – MIN
ACTL Current measured value
Starting the measurement series and selecting the display
Finding Minimum and Maximum Values
You can start the series of measurements either by pressing
MOD and selecting the desired display— as described on the
following pages— or by external signal over the switching
inputs at the D-sub connection EXT (X41, see “Switching
Inputs and Outputs”).
1)
MAX
ACTL
Series of measurements: The MIN, MAX and DIFF values of an
uneven surface
DIFF
MIN
10
When a series of measurements is started, the internal MIN/
MAX/DIFF memory is reset.
1)
Only in the linear measurement mode.
Example: Measurement series for determining eccentricity
e
Starting a series of measurements
Switching between MIN, MAX, DIFF and ACTL displays
Repeatedly
MOD
MAX
Repeatedly
Select the display for a series of measurements.
The selected indicator blinks (here, MAX).
Confirm selection.
... until the START indicator blinks.
MOD
START
Start the series of measurements.
Indicator preselection
Press MOD to start the series of measurements and select the
display with the indicators.
Operating parameter P86 allows you to define which indicator
is displayed first when MOD is pressed.
It is not possible to switch between the displays as
described below if the switching input for external
control of the series of measurements (pin 6 on
D-sub connection EXT) is active.
As an alternative, you can select the display with operating
parameter P21 (see “Operating Parameters”).
Repeatedly
MOD
MIN
The display now shows the smallest value measured during the
current series of measurements.
Select the new display of a series of
measurements.
The selected indicator blinks (here, MIN).
Confirm the change.
Finding Minimum and Maximum Values
11
Starting a new series of measurements
Repeatedly
MOD
START
Ending a series of measurements
Repeatedly
MOD
Select the indicator START.
The indicator START blinks.
Start a new series of measurements.
Select the active indicator (MIN, ACTL,
MAX, DIFF).
The indicator that lit up last blinks.
End the series of measurements.
Finding Minimum and Maximum Values
or
Repeatedly
MOD
START
Select the indicator START.
The START indicator blinks.
12
End the series of measurements.
Sorting and Tolerance Checking
In the sorting and tolerance checking mode, the display unit
compares the displayed value with the programmed upper and
lower sorting limits. The sorting and tolerance checking mode is
enabled and disabled with operating parameter P17.
Entering sorting limits
Sorting limits are entered in operating parameters P18 and P19
(see “Operating Parameters”).
Sorting signals
The indicators and switching outputs at D-sub connection EXT
(see section on X41) sort the display value into one of three
classes.
Display Meaning
= Measured value is within sorting limits
< Measured value is smaller than lower sorting limit
> Measured value is greater than upper sorting limit
Operating parameters for sorting and tolerance checking
P17 SORT Sorting ON/OFF
P18 L.LIMIT Lower sorting limit
P19 U.LIMIT Upper sorting limit
Part 1
Part 2
Part 3
Example: Upper sorting limit = 26.02 mm
Lower sorting limit = 26.00 mm
Accept
Sorting and Tolerance Checking
Rework
Reject
13
Measured Value Output
For technical information on the RS-232-C/V.24 data
interface (X31), information on the data format, etc.,
see the chapter “RS-232-C/V.24 Interface (X31).”
Measured values can be output over the RS-232-C/V.24
interface (X31), for example to a printer or PC.
There are several ways to start measured value output:
➤➤
➤ In the linear measurement mode:
➤➤
Measured Value Output
Press MOD repeatedly until the PRINT indicator blinks,
then start measured value output with ENT.
In the angular measurement mode:
Press the MOD key (this feature can be disabled with the
operating parameter 86).
or
➤➤
➤ Input the command STX (Ctrl B) over the RXD input of the
➤➤
RS-232-C/V.24 interface (X31);
or
➤➤
➤ Input a signal for measured data output (Pulse or Contact)
➤➤
at the D-sub connection EXT (X41).
PC
START PRINT
MOD
in.
123
0.–CL
REF21SET
=
<>
HEIDENHAIN
MIN ACTL MAX DIFF
789
456
The RS-232-C/V.24 interface (X31) enables you to connect a
printer or a PC to your display unit
14
Display Freeze
With the latch command, the display can be stopped for any
period of time. The internal counter remains active. Parameter
P23 selects the “display freeze” mode and offers three
settings:
• Concurrent display, no display freeze— the display value
is the current measured value.
• Frozen display— display value is frozen and is updated with
each signal for measured value output.
• Frozen/concurrent display— display remains frozen as
long as the latch signal is present; after the signal, the
display resumes continuous display of the current measured values.
Position
Latch
signal
Frozen
display
Display Freeze
Frozen/
concurrent
display
15
Error Messages
Display Effect/Cause
RS232 FAST Command for measured value
output followed too quickly by
another.
1)
SIGNAL Encoder signal is too weak.
Error Messages
The scale may be contaminated.
DSR.MISSING The connected device has not sent
a DSR signal.
1)
REF. ERR. The spacing of the reference marks
as defined in P43 is not the actual
spacing.
1)
FORMAT ERR. Data format, baud rate, etc. do not
1)
match.
FREQUENCY Input frequency too high for encoder
input. Traversing speed may be too
1)
fast.
MEMORY ERR. Checksum error: Check the datum,
operating parameters and compensation values for nonlinear axis error
compensation. If this error recurs,
contact your service agency!
1)
These errors are important for the attached device. The
error signal (pin 19) at D-sub connection EXT is active.
Other Error Displays
If “OVERFLOW” appears, the measured value is too large or
too small:
➤➤
➤ Set a new datum.
➤➤
or
➤➤
➤ Traverse back.
➤➤
1)
If all sorting signals light up, the upper sorting limit is smaller
than the lower limit:
➤➤
➤ Change operating parameters P18 and/or P19.
➤➤
To clear error messages:
Once you have removed the cause of the error:
➤➤
➤ Clear the error message with the CL key.
➤➤
16
Loading...