HEIDENHAIN NPD 281 User Manual v.3

ND 281 NDP 281

User's Manual

ND 281 NDP 281

Measured value display

5/97

Display of actual value and input

(7-segment LED, 9 decades with algebraic sign)

Numeric keypad with decimal point

789

456

REF

SET

MIN ACTL MAX DIFF

START PRINT

in.

123

–CL

HEIDENHAIN

Status display with indicators

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

• Start series of measurements

• Switch display for series of measurements

• Start measured value output “PRINT”

• Select parameter after switch-on

• Page forward in parameter list

• Delete entry

• Set display to zero (P80!)

• CL plus MOD: select parameter list

• CL plus number: select parameter

• Algebraic sign

• Reduce parameter value

• Decimal point

• Increase parameter value

Indicator Meaning

REF If decimal points are additionally blinking:

Display is waiting for reference mark traversing. If decimal points are 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 in. Position values in inches 1 / 2 Selected datum point PRINT Blinking: Display is waiting for ENT to

be depressed for data output SET Blinking: Display is waiting for input

values

< / = / > Sorting and tolerance checking:

measured value smaller than lower

sorting limit / within the sorting limits /

greater than upper sorting limit

MAX / Series of measurements: Minimum /

MIN DIFF / ACTL maximum / greatest difference

(MAX–MIN) / current measured value

Blinking: Confirm selection or deselect

function

START Series of measurements is running

Blinking: Display is waiting for signal to

start series of measurements

Items delivered with ND 281

Measured value display unit, ND 281A bench-top design Encoder input 11 µA

ND 281V

Encoder input 1 V

Power cord 3 m (9.9 ft)

Items Delivered

User's Manual ND 281/NDP 281 Adhesive plug-in feet For stacking ND 281 units

Items delivered with NDP 281

NDP 281 Measured value display unit,

Encoder input 11 µA

Power terminal User's Manual ND 281/NDP 281

This manual is for the measured value display units ND 281 and NDP 281 with the following software number or higher:

Id. Nr 283 481 ..

Id. Nr 322 353 ..

for panel mounting

Id. Nr 289 214 ..

246 181-01

The software number is indicated on a label on the

rear panel.

Contents

Working with the ND Display Units

Position Encoders and Reference Marks 6 Switch-On, Crossing Over the Reference Marks 7 Datum Setting 8 Finding Minimum and Maximum Values 9 Sorting and Tolerance Checking 12 Measured Value Output 13 Display Freeze 14 Error Messages 15

Installation and Specifications

Rear Panel; Accessories 16 Mounting 18 Power Connection 19 Operating Parameters 20

List of Operating Parameters 22

Linear Encoders 25 RS-232-C/V.24 Interface (X31) 30 Switching Inputs and Outputs EXT (X41) 35 Distance-To-Go Mode 40 Specifications 41

Dimensions 42

Contents

Position Encoders and Reference Marks

The ND 281 and NDP 281 display units are primarily intended for use with photoelectrical linear encoders with sinusoidal 11-µA MT length gauges with 11 µA

These length gauges have one reference mark. The scales of other photoelectric linear encoders (see “Linear Encoders”) can contain one reference mark or several reference marks.

or 1-VPP signals: primarily for HEIDENHAIN

distance-coded

Scale in Distance-coded linear encoder 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 re-establish 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

Position Encoders and Reference Marks

length gauge position and display values which you last defined by setting the datum.

If the linear encoders have distance-coded

reference marks, you only need to traverse a maximum of 20 mm to restore the datum.

Reference mark

Reference marks on linear encoders

Switch-On, Crossing Over the Reference Marks

REF Mode

➤➤

➤

➤➤

ENT...CL

5 . 6 9 7

For automation purposes, crossing over the reference marks and the display ENT ... CL can be disabled with parameter P82.

Turn on power.

(Switch located on rear panel.)

•

• Indicator REF 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 now is ready for operation.

is displayed.

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.

Press the CL key if you choose not to cross over 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.

Switch-On, Crossing Over the Reference Marks

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

Datum Setting

(see P79, P80), or

• By external signal

Select datum 1 or 2.

Enter numerical value (here, 5).

Confirm the entered numerical value.

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 MT's actual position.

Without datum setting: unknown assignment of measured values to

positions

20˜

15˜

10˜

5˜

After datum setting: Assignment of measured values to positions

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

MAX

ACTL

Series of measurements: The MIN, MAX and DIFF values of an uneven surface

DIFF

MIN

Starting the series of measurements and selecting the display

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 page 34). When a series of measurements is started, the internal MIN/ MAX/DIFF memory is reset.

2e = r

MAX

Ð r

MIN

e = DIFF

Example: Series of measurements for determining eccentricity

Finding Minimum and Maximum Values

Starting a series of measurements

Switching between MIN, MAX, DIFF and ACTL displays

repeatedly

MOD

Select the display for a series of measurements.

The selected indicator blinks (here, MAX).

MAX

Confirm selection.

repeatedly

... until the indicator START blinks.

MOD

START

Start the series of measurements.

Finding Minimum and Maximum Values

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

Select the new display of a series of measurements.

The selected indicator blinks (here, MIN).

MIN

Confirm the change.

The display now shows the smallest value measured during

the current series of measurements.

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

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

Part 1

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 (X41, see page 34) sort the display value into one of three classes.

Sorting and Tolerance Checking

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

Sorting ON/OFF Lower sorting limit Upper sorting limit

Part 2

Part 3

Example: Upper sorting limit = 26.02 mm

Lower sorting limit = 26.00 mm

gut

Rework

Nacharbeit

Reject

Ausschu§˜

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:

➤➤

➤ Press MOD repeatedly until the indicator PRINT blinks,

➤➤

then start measured value output with ENT;

➤➤

➤Input the command STX (Ctrl B) over the RXD input of the

➤➤

RS-232-C/V.24 interface (X31);

➤➤

➤ Input a signal for measured data output (Pulse or Contact)

➤➤

at the D-sub connection EXT (X41).

789

456

START PRINT

MOD

in.

123

0.–CL

REF21 SET

MIN ACTL MAX DIFF

HEIDENHAIN

The RS-232-C/V.24 interface (X31) enables you to connect a printer or a PC to your display unit

Measured Value Output

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

Display Freeze

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

Frozen/ concurrent display

РРРРРРРРРРРРРРРРРРРРРРРРРРРРРРРРР

0.000

0.004

0.005

0.000

0.006

0.000

0.007

0.008

0.000

0.009

0.000

0.010

0.011

0.000

0.012

0.014

0.013

0.014

0.023

0.024

0.014

0.025

0.014

0.026

0.027

0.014

0.028

0.030

0.029

0.030

+ 30 hidden pages