Newport LDS1000 User Manual

1 EDH0170FE1010 – 09/98

LDS1000 Controller for Laser Diode Sensors

LDS1000
Controller for Laser Diode Sensors

1.0 Introduction

This manual describes the operations and conditions necessary for the
proper use and working of the NEWPORT LDS1000 Controller.

It also provides the basic maintenance operations that are useful to keep
the instrument in good working order.

IMPORTANT

NEWPORT LDS series sensors are measuring instruments that provides
results of measurements. The calibration certificate drawn up by NEW­PORT for each delivery, or when an instrument is newly calibrated must
ALWAYS be supplied with the sensor. It provides the values of the para­meters that must be stored in the memory of the LDS1000 electronic
controller so that the instrument gives accurate measurements. BEFORE
any measuring operation, the operator must make sure that the parame­ters that are used by the electronic controller are the ones that the ins­trument is designed to use. Refer to the corresponding chapter to check
and modify the sensor parameters.

RECOMMANDATIONS

You are strongly advised to read the chapter entitled “First use” careful­ly before connecting your autocollimator.

2.0 Description

The LDS1000 Controller is designed to drive sensors of the NEWPORT LDS
series (for example, LDS-Vector autocollimator or STR500-H rectitude sen­sor). The latter are compact and self-contained measuring instruments.
The LDS1000 electronic controller provides the means of displaying angu­lar variations by measuring the movement of a spot of light on a position
sensing device. It has the capacity, off-line, to store up to 2048 measu­rements (14336 measurements with the extended memory option) and to
calculate the averages of these measurements.

When linked to a personal computer it provides the possibility of proces­sing and recording the measurements.

This manual is designed to facilitate the use of the LDS1000 Controller for
all its modes of operation.

A second user’s manual exists which describes and facilitates the use of
the sensor.

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LDS1000 Controller for Laser Diode Sensors

2.1 Equipment

The LDS1000 electronic controller is delivered with:

•A RS-232-C lead.

•The present user’s manual.

•The LDS-TOOLS Software.

•A connection cable (5 or 10 meters, depending on the order).

•As well as the extra accessories and options that may be ordered.

The sensor is delivered in a protection case which contains:

•The optical head.

•The control certificate.

•The present user’s manual.

2.2 Modes of Operation

2.2.1 Manual Mode

The LDS1000 Controller displays angular rotation values of the mirror on a
frontal display screen. The operator uses the display and the active but­tons on the front panel to:

•Read the measurements.

•Modify the integration constant.

•Define the zero point.

•Program the parameters of the connected sensor.

•Modify the communication parameters (RS-232-C or IEEE-488).

•Activate the analog outputs where available.
Refer to the chapter entitled: “Off-line use”.

ATTENTION RAYONNEMENT LASER

EN CAS D'OUVERTURE

EXPOSITION DANGEREUSE

AU FAISCEAU

RAYONNEMENT LASER

NE PAS REGARDER DANS LE FAISCEAU

APPAREIL A LASER DE CLASSE 2

Puissance maxi = 0,9 mW à 670 nm

3 EDH0170FE1010 – 09/98

LDS1000 Controller for Laser Diode Sensors

2.2.2 Remote Mode

When linked to a computer by RS-232-C or IEEE-488 connection, the
LDS1000 Controller communicates by ASCII messages. The buttons on the
front panel of the controller are no longer valid.

The following functions are possible:

•Reading the controller’s programmed parameters.

•Modification of the integration constant.

•Transmission of instantaneous values measured.

•Acquisition in the controller’s internal memory, of a number N of points,
at the frequency F.

•Acquisition in the controller’s internal memory, of a number N of points,
at the frequency F, the beginning of the acquisition is started by an
external signal (Trigger).

•Acquisition in the controller’s internal memory of a number N of points,
each acquisition being started by an external signal (Trigger).

Refer to the chapter entitled: “Use with a computer interface”.

2.2.3 Analog Mode

Analog outputs are only available on models that are equipped with this
option. This must be specified at the time of ordering.

There are two voltages at the analog outputs that are respectively propor­tional to the angular measurements Y and Z of the equipment.

This enables:

•Connection to an analog acquisition chain.

•Visualization of positions on an oscilloscope.

•Use of the LDS-Vector autocollimator for analog controls.

These outputs are obtained by a digital/analog conversion of the values
calculated by the controller.

This conversion is carried out in real time at a frequency of 2000 Hz.
Refer to the chapter entitled: “Off-line use”.

2.3 Available Versions

2.3.1 Controller

The electronic controller is available in eight versions that offer different
measuring possibilities. The references are as follows:

LDS1000 Controller LDS1000-OPT BB CC

with: BB NN No cable.

01 Cable length 5 meters.
02 Cable length 10 meters.

CC NN No controller.

02 Standard controller European standard (220V,

2manuals and EU cable).

12 Analog option controller, EU standard.
22 14K memory option controller, EU standard.
32 2-option controller, EU standard.

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LDS1000 Controller for Laser Diode Sensors

2.3.2 Sensors

Autocollimator, bilingual user’s manual LDS-Vector
Rectitude sensor, bilingual user’s manual STR500-H

2.3.3 Accessories and Additional Equipment Kits

Calibration blade kit, with certificate LDS-CAL01
2-theta adjustable mount LDS-SL
2-theta + XY adjustable mount LDS-SLXY
4 movement adjustable mount on X26 (complete, for LDS-Vector)

LDS-X26-V

2.4 Dimensions

O

I

329.5 (Depth 352)

IEEE-488

RS-232-C

Y & Z

Outputs

Sensor

Connector

– Front View –

– Rear View –

83.5

21

PWOK

Input

TRIG

Input

!

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LDS1000 Controller for Laser Diode Sensors

3.0 Principle of Operation

3.1 Laser Diode Sensors

Laser diode sensors of the NEWPORT LDS series use identical technologies
for the emission and reception of optical signals, but according to a diffe­rent optical diagram.

The emission is performed by a Laser diode controlled and modulated at
10 kHz.

The reception is performed by a position sensing device that provides ana­log voltages.

From the electronic controller’s point of view, that becomes:

•Supply the necessary power to the laser diode and to the pre-amplifying
electronic controller.

•Monitor break down and defects.

•Collect the return signals from the analog sensor.

This data is processed by the controller, corrected according to the para­meters provided by calibration and usable depending on the different
modes (display, memorization, transmission to the computer interface,
analog output [available as an option]).

3.2 Electronic Controller

The LDS1000 Controller performs:

•Fast acquisition at a set frequency of 2 kHz.

•Analog to digital conversion.

•Correction and integration calculation.

•Memory and display management.

Its technology is based on a 68000, 16 MHz microprocessor.
This controller offers a clear display of the values measured on a luminous

screen and communication via RS-232-C and IEEE-488 interfaces.
One particular model is available with calibrated analog outputs, that are

proportional to the values measured.

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LDS1000 Controller for Laser Diode Sensors

4.0 Specification

The LDS1000 Controller can be used in conjunction with various optical
heads.. The dependent characteristics of the optical head are given in the
individual manuals.

The measurement results can only take on their full meaning in relation to
a unit that represents the value to be measured (distance, angle…). The
controller enables the result to be displayed on the unit that corresponds
to the sensor used.

4.1 General Characteristics

4.1.1 LDS-Vector Optical Head (example of Sensor)

•Wavelength 670 nm

•Peak power 900 µW

•Modulation 10 kHz

•Beam diameter 31 mm

•Beam direction <0.5 mrad in relation with autocollimator body

•Equivalent focal length 280 mm

•Beam divergence 0.1 mrad

•Ocular field ±15 mrad

•Measurement range ±2000 µrad

•Weight 1.065 kg

4.1.2 LDS1000 Controller

•Microprocessor 68000 (32 bits - 16 MHz)

•Display 2

x20 characters, adjustable brightness

•Interfaces RS-232-C and IEEE-488

•Measurement memory 2048 spots or
14336 spots depending on the option

•Analog output Available as an option

•TTL TRIGG input Measurement synchronization

•TTL PWOK output Beam signal

•Power supply 90/264 VAC, 50/60 Hz

•Consumption 30 VA

4.1.3 Measurements

•Digital resolution 0.1 µrad

•Measurement range ±2000 µrad

•Measurement error ±(1 ±0.02

xmeasurement.) µrad (i.e. ±2%)

•Max. measuring noise 0.02 µrad/√Hz

•Sampling frequency 2000 Hz

•Digital integration from 0.5 msec to 1 sec

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LDS1000 Controller for Laser Diode Sensors

4.1.4 Environment

The performances of an optical sensor greatly depend on the conditions in
which it is used.

The contractual characteristics are specified in the manual that goes with
each sensor of the LDS series.

The operating limits of the LDS1000 Controller are the following:

•Operating temperature +15 °C to +25 °C

•Humidity 10% to 80%

•Storage temperature -10 °C to + 50 °C
Refer to the paragraph entitled “Specification Validity” in each user’s

manual for the performances of the sensors according to the conditions of
use.

4.1.5 RS-232-C and IEEE-488 Interfaces

RS-232-C interface

Baud rate 300 to 19200

IEEE-488 interface

Mode SRQ management

4.1.6 Analog Outputs

Analog outputs are only available if the option has been chosen.

•Refresh frequency 2000 Hz

•Digital low-pass filter 1 to 2000 Hz

•Output range ±10 V

•Scale factor 5 mV/incr to 1000 mV/incr

•Resolution 0.5 increment

•Electronic noise 1 mV rms

•Distortion 0.5% (electronic)

•Maximum Offset 50 mV typical

•Output impedance 10 Ω

•Discrepancy equivalent to a pure delay of 1.1 msec (without integration).

•Attenuation equivalent to the one of an order 1 low-pass filter with
600Hz cutoff frequency.

WARNING: SPECTRAL WITHDRAWAL

The analog outputs use an intermediary calculation stage that is based
on a sample at 2000 Hz. This will limit the use of the LDS sensor for stu­dying signals that do not have a significant spectral component over
1000 Hz (this sort of component would find themselves “withdrawn” and
would appear for lower frequencies).

4.2 Validity of Specifications

Refer also to the paragraph entitled “Specification Validity” in each user’s
manual for the performances of the sensors according to the conditions of
use.

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LDS1000 Controller for Laser Diode Sensors

4.2.1 Calibration

A reading of the linear errors according to the angle measured is provided
with each sensor. This calibration certificate gives, in particular, the value
of the principal parameters to be used to configure the LDS1000 electronic
controller:

•S/N: Series number of the optical head.

•Type: RT (Rotation) for LDS-Vector or TR (Translation) for STR500-H.

X: Beam Axis; Y: Horizontal Axis; Z: Vertical Axis.

–Type RT (Rotation):

Y: Rotation around Y axis.
Z: Rotation around Z axis.

–Type TR (Translation):

Y: Parallel translation with Y axis.
Z: Parallel translation with Z axis.

•Ycoef:Linear correction factor for axis Y.

•Yincr:Count increments for axis Y.

•Yunit:Unit displayed for axis Y.

•Yofs1, Yofs2:Channel Y electronic offsets.

•Zcoef:Linear correction factor for axis Z.

•Zincr:Count increments for axis Z.

•Zunit:Unit displayed for axis Z.

•Zofs1, Zofs2:Channel Z electronic offsets.
These parameters were optimized when the instrument was calibrated in

order to obtain the best results. You are advised not to modify them
without reason.

These parameters have been defined for the following conditions of use:

•Temperature 22 °C ±2 °C

•Mirror diameter >31 mm

•Reflectivity 80% at 670 nm

•Working distance 0.1 m

4.3 Noise Reduction

The LDS1000 Controller constantly carries out acquisitions at a rate of 2000
values per second.

These acquisitions are dealt with on request (transformation of electric
signals into metrological values) for display or emission on a connection.

Depending on the programming of the electronic controller, the returned
value corresponds either to the last acquisition carried out (no average) or
to the average of the last N acquisitions.

ATTENTION RAYONNEMENT LASER

EN CAS D'OUVERTURE

EXPOSITION DANGEREUSE

AU FAISCEAU

RAYONNEMENT LASER

NE PAS REGARDER DANS LE FAISCEAU
APPAREIL A LASER DE CLASSE 2

Puissance maxi = 0,9 mW à 670 nm

+Z

+Z

+Y

+X

+Y

9 EDH0170FE1010 – 09/98

LDS1000 Controller for Laser Diode Sensors

In the second case, a low-pass digital selection is carried out which reduces
the noise.

The noise reduction evolves like the square root of the number N of avera­ged samples, which is itself equal to the averaging time to acquisition per­iod ratio.

The acquisition period is always equal to 0.5 msec (2 kHz).
The duration of the averaging is fixed by the integration constant that can

be parametered INTG.
Refer to the user’s manual of the LDS sensor concerned.

4.4 Offset Coefficient Adjustment

The Yofs1, Yofs2, Zofs1 and Zofs2 coefficients are normaly set to zero
value.

When the reflected light is becoming low, because of poor reflectivity or
small mirror aperture, it is necessary to take into account the value of the
electronic offsets of the detector.

The LDS1000 Controller is designed to make this correction very easily, by
introducing offset coefficients into its memory.

The following procedure must be accomplished:
❶The values of offsets are reached when the instrument does not receive

any light.
In order to get these values, place a black screen in front of the exit

pupil of the instrument.
The requested values are then dispayed by the LDS1000 in the specific

test mode, described in chapter 7.3.

=> (F5) => (F4) => (F2)

The first line gives Yofs1 and Yofs2.
The second line gives Zofs1 and Zofs2.

❷Take notes of these values and go to LDS1000 parameter setting, as

explained in chapter 7.4.

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LDS1000 Controller for Laser Diode Sensors

5.0 Starting the Equipment

5.1 Setting Up

The setting up of the sensor is explained in each user’s manual of the LDS
instruments.

RECOMMANDATION

You are advised to read the user’s manuals corresponding to each sensor
delivered. They contain important information for optimal use of the ins­truments. These instructions can vary from one sensor to another.

5.1.1 Mounting

Small movement measurements require specific precautions as far as the
quality of the mounting of the equipment is concerned. It is particularly
important to make sure that the sensor, the reflector and their correspon­ding supports are solid

5.2 Electric Connections

CAUTION

Before connecting check that all equipment is switched off.

CAUTION

Do not use any cable other than the one supplied by NEWPORT.

The cable provided connects the sensor to the electronic controller. The
male part should be connected to the optical head, the female part to the
controller. Please ensure that all connections are correctly screwed in.

The cable is available in two standard lengths:

Cable for LDS1000, length 5 meters LDS1000-OPT01NN

Cable for LDS1000, length 10 meters LDS1000-OPT02NN
For longer lengths, please consult us.
A lead ensures the connection to the mains supply on a switch and fuse

base.
The controller is equipped with a self-selecting input voltage power supply

(from 90 V to 250 V).
Set the switch to "0" (OFF) position.

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LDS1000 Controller for Laser Diode Sensors

5.3 Power Up

5.3.1 Power Up Messages

Link up the controller to the mains. Set the switch to “I” (IN).
Once turned on, the controller goes into its initialization phase and dis-

plays a welcome message.

Then, the display of values measured according to programming parame­ters is displayed:

This presumes that the autocollimator is stationary in front of a mirror
which sends the correct beam into the measuring range (see paragraph:
“Alignment”).

In other cases, the controller displays the value of the limits of the measu­ring range (the most frequent being -2000 µrad) instead of the value measu­red on the given axis:

See paragraph: “Alignment”.
Other possible messages:

LASER ERROR: This message indicates a connection error in the optical
head or a laser diode emission fault.

This message indicates that the controller is connected to a computer on
which software is running, which has sent the command to freeze the dis­play. Reset the software parameters to regain control.

This type of message indicates, for controllers equipped with analog
options, that the analog output mode is active. Press the MAIN key to
return to the main menu.

5.3.2 Alignment

To visualize an angular measurement, make sure that the return beam
penetrates the LDS-Vector autocollimator and that the return energy is
powerful enough.

The procedure for rapid set up is explained in the user’s manual supplied
with each instrument.

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LDS1000 Controller for Laser Diode Sensors

6.0 Configuring the Equipment

The controller is configured in manual mode, using the buttons and the dis­play available on the front panel of the LDS1000 Controller. This must be
done before the instruments can be used.

6.1 Sensor Configuration

The LDS1000 electronic controller can receive a variety of sensors: an LDS­Vector electronic autocollimator or an STR500-H rectitude sensor. In the
same laboratory, it is possible to find several sensors installed for a single
controller which is connected to one or other of the sensors depending on
the needs.

To simplify programming and to minimize the risk of errors, the LDS1000
electronic controller has a memory that can store all the parameters of 10
different sensors. Only Manual mode makes it possible to modify the num­ber of the sensor being used, as this modification requires manual adjust­ment on the controller (physically connecting the sensor required).

To configure the sensor you will need to consult the control statement deli­vered with each piece of equipment. Should you lose it, a duplicate of this
document which is of great importance is kept by our metrology depart­ment. Just note the number that is marked on the sensor and we will be
able to send you a copy of the document.

The configuration of the sensor is carried out in manual mode and enables:

•The active sensor to be selected.

•The parameters of the active sensor to be visualized.

•The parameters of the active sensor to be modified.
See the chapter entitled: “Off-line use”.

6.2 Interface Configuration

Manual mode enables the parameters and the communication mode of the
controller to be chosen. It is useful to check these values before procee­ding with a connection to a computer. This must be done before using the
instrument in Interface Mode.

The LDS1000 Controller communicates with a computer via two standard
protocols available:

•RS-232-C.

•IEEE-488.

6.2.1 RS-232-C Interface

The RS-232-C protocol is available on most commercial computers on ports
COM1 or COM2. The LDS1000 Controller is delivered with a RS-232-C lead
comprising a classical Sub-D9 connector, as well as a Sub-D9/Sub-D25 adapter.

Depending on the standard chosen by the computer manufacturer, it is
always possible to carry out the RS-232-C communication with the LDS1000
Controller. A program written on a given computer will be able to use the
RS-232-C outputs available on another computer without any problems (on
the condition that the right number of the port on which the LDS1000
Controller is connected is given).

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LDS1000 Controller for Laser Diode Sensors

The parameters of the RS-232-C interface are the following:

•BAUD RATE Interface speed.

•MSG TERM End of message character.

•WORD LENGTH Length of the transmitted chain.

•STOP BITS Number of stop bits.

•PARITY Parity used by the interface.

6.2.2 IEEE-488 Interface

The IEEE-488 protocol is only possible when the computer is equipped with a
special card that allows IEEE-488 communication. There are several different
models available on the market. Please note that they are not compatible bet­ween themselves. As a result, a software program written for a IEEE-488 card
of a model will not work with another IEEE-488 card.

The parameters of the IEEE-488 interface are the following:

•MSG TERM End of message character.

•PRIM ADRESS Instrument’s primary address.

•SECOND ADRESS Instrument’s secondary address.

•TIME OUT Wait time.
The IEEE-488 interface enables several different instruments to be connec-

ted to the same computer input. It is quicker than the RS-232-C interface. For
this connection, the controller operates in SRQ mode.

The parameters of the two communicating instruments must be identical to
obtain the communication (in fact the two instruments must speak the same
language in order to understand each other). The LDS1000 Controller is
considered to be a slave in the communication protocol. Its parameters
must therefore be chosen in accordance with those of the master computer.

Cf. Chapter entitled: “Off-line use”.

6.3 Controller Configuration

The LDS1000 Controller has a program and material configuration that
depends on the options chosen at the time of ordering. In particular, the
internal software version, the size of the memory installed and the installa­tion of the analog output option represent information that is accessible in
manual mode.

Moreover, so that you can comfortably use the controller in different
atmospheres, the brightness of the light can be adjusted.

Accessible functions:

•Reading the version.

•Display brightness.

•Memory size.

•Analog output option.
Refer to the chapter: “Off-line use”.

EDH0170FE1010 – 09/98 14

LDS1000 Controller for Laser Diode Sensors

6.4 Analog Output Configuration

The analog outputs are only available by manual mode on the models
equipped with this option.

It is possible to modify the following parameters:
Refer to the chapter: “Off-line use”.

NOTE

The analog outputs deliver two voltages that are respectively proportio­nal to the Y and Z measurements of the equipment.

Among other things this enables:

•Connection to an analog acquisition chain.

•Visualization of positions on an oscilloscope.

•Use of the sensor for analog controls.
These outputs are obtained by a digital/analog conversion of the values

calculated by the controller.
This conversion is carried out in real time at a frequency of 2000 Hz. It

imposes the following limits:

•Resolution limitation 0.5 increment

•Further measurement distortion 0.5%

•Extra noise 1 mV rms (measured with a

load of 1 MΩ).

•Maximum offset 50 mV typical.

•Discrepancy equivalent to a pure delay of 1.1 msec (without integration).

•Attenuation equivalent to the one of an order 1 low-pass filter with

600Hz cutoff frequency.

The output voltages take into account the averaging defined by INTG. The
full scale voltage variation (±10 V) matches the full scale measurement
variation, i.e. a scale factor of 5 mV/increment.

A multiplying factor defined by GAIN (1 to 200) makes it possible to change
this scale factor from 5 to 1000 mV/increment. The gain comes with a limi­tation of the angular range that can be visualized (outputs limited at ±10 V).

The impedance of the outputs if equal to 10 Ωand the maximum current
they can deliver is 4 mA.

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LDS1000 Controller for Laser Diode Sensors

7.0 Off-Line Use (Manual Mode)

The LDS1000 Controller has two modes of operation.
Manual mode which enables:

•The configuration of the controller in accordance with the parameters
of the sensor used.

•To carry out measurements on values displayed.

•To modify the integration time, and the display mode.

•To parameter the communication interface.

•To select the analog outputs (if option available).

Interface mode which enables:

•Flying spot reading of values measured,

•Execution of acquisition sequences that are synchronized or not.

•Reading the sensor status.

Manual mode is valid when the autocollimator is in off-line use, to perform
measurements from the controller display. It is also used to parameter the
computer interface or to access the analog outputs option (if it exists).

7.1 Access to Manual Mode

Manual mode is directly accessible on the controller at the time of Power
up, except in the following cases:

•Sensor non connected or damaged (Laser error).

•Analog output mode valid (Refer to the corresponding chapter).

•Communication in progress via RS-232-C or IEEE-488 (Refer to the
Interface Mode chapter).

The starting point is the main Menu which is the controller’s usual mode of
operation.

Access to the different Menus, parameter scrolling and the choice of values
is obtained by pressing one of the 5 buttons on the front panel of the
controller (F1 to F5).

Position of the buttons on the LDS1000 Controller.

F5

LDS1000

F1 F2 F3 F4

F5

F1 F2 F3 F4

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LDS1000 Controller for Laser Diode Sensors

The mnemonics corresponding to the function of each button are indicated
by the display shown by the button.

For example, in the main menu , the F5 key enables the function

to be selected, and the F4 key selects the function . The other

keys F1, F2 and F3 have no effect.

WARNING

As a result the keys do not always correspond to the same functions.

7.2 Manual Mode Functions

The main menu gives access to two sub-menus:

• => (F5key)
Ce Mode permet l’accès aux fonctions suivantes:

Display freeze.
Display relative to a current position.
Graphic display.
Modification of the integration constant.
Display the light received.
Test Mode (maintenance).

• => (F4key)
This Mode gives access to the following functions:

Reading/Modification of current sensor parameters.

Memorization / Selection of 10 different sensor configurations.

Choice of communication parameters(RS-232-C, IEEE-488).
Information on the software version, the available memory and

the display brightness.

Commutation to analog outputs (only if the option exists).

The rolling menus use the following symbols and mnemonics:

Modification of current parameters.
Visualization of current parameters.
Information on the software version, the available memory and

the display brightness.

Reset with default values.
Save modifications (after ).
Message confirmation.
Abandon.
Scrolling of modifiable parameters (or cursor movement).
Next highest value (+1 for digital values).
Lower value (-1 for digital values).
Return directly to main Menu.

After any modification, the configuration will be saved when the equipment
is switched off.

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LDS1000 Controller for Laser Diode Sensors

MASTER RESET

On switching on, if you press the F5 key for a few seconds, the controller
suggests changing all the parameters to default values.

Selecting (F4key) will destroy all the data fed into the controller and
will replace all values with default values.

7.3 Measuring Functions

Access to measuring functions, from the main menu, is done with the F5
key:

=> (F5) => …

7.3.1 Display Freeze

=> (F5) => (F1)

The display freeze is useful when carrying out measurements of a vibrating
or moving system spread out over time. The display is frozen and the two
values that correspond to the same instant are available on the screen.

It is therefore possible to read them without haste (this is a flying spot pic­ture of a position).

(F5)Return to main menu.
(F4)Normal display.
(F4)Freeze the display.

7.3.2 Offset Origin

=> (F5) => (F2)

This mode, also called relative display, makes it possible to set the current
point as the origin. The values displayed are therefore given in relation to
this point. This mode is practical to find out the angular distance between
two given positions, without having to adjust the zero point to the center of
the sensor.

However, it is necessary to make sure that you do not go beyond the min.
and max. limits on the cell. You are advised to set the first point near the
center of the sensor.

(F5)Return to main menu.
(F4)Freeze the relative display.
(F4)Relative display.

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LDS1000 Controller for Laser Diode Sensors

7.3.3 Integration Constant

=> (F5) => (F3)

The accuracy that can be obtained on a measurement depends on the num­ber of readings carried out for that measurement.

In manual mode, the LDS1000 electronic controller carries out measu­rements at a frequency of 2 kHz. Its own resolution at this frequency is 0.8
µrad when using a standard LDS-Vector autocollimator.

By calculating the average of a large number of measurements, it is pos­sible to obtain a much higher resolution, to the detriment of the system’s
pass band.

The LDS1000 Controller carries out a sliding average of N successive
values, in relation to the INTG parameter that can be selected with this
menu (N = 2 xINTG).

(F2)Lowest INTG value.
(F3)Highest INTG value.
(F5)Return to main menu.

Possible values: INTG = 0,5; 1; 2; 5; 10; 20; 50; 100; 200; 500; 1000
Default value: INTG = 100
Unit: msec

7.3.4 Graphic Display

=> (F5) => (F4) => (F3)

In order to facilitate alignments, a display in the form of a Bar-Graph is
recommended. For each axis, the number 8 digit is considered as the opti­cal center of the autocollimator. The angles measured successively light up
the adjacent digits (7 on each side), logarithmically for accurate alignment
mode. Positive space values light up the digits to the right. The alignment
around the center of the sensor is achieved by switching off as many digits
as possible.

In alignment mode, a function (F4) enables measurements to be per­formed in relation to the current position which becomes a reference point.

(F5)Return to main menu.

7.3.5 Display Light Received

=> (F5) => (F4) => (F1)

To check if the instrument is working properly, make sure that the rate of
light returned to the sensor is sufficient. This mode is especially useful for
setting up the instrument in complex assemblies, in order to avoid substan­tial vignetting. The best results are obtained when a maximum amount of
light is received.

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LDS1000 Controller for Laser Diode Sensors

The display is in % in relation to the nominal value established at 100%.

(F5)Return to main menu.

7.3.6 Maintenance Mode

=> (F5) => (F4) => (F2)

Here the brut value of the 4 channels of the analog/digital converter from
the sensor is displayed. Interpreting the values depends on the sensor that
is in place. Their read-out enables the sensor’s electronic offset to be cor­rected.

(F5)Return to main menu.

7.4 Configuration Functions

Here we find the way to parameter the following elements:

•Parameter input of the sensor used.

•Parameter input of the controller.

•Interface parameter input.

7.4.1 Parameter Input of the Current Sensor or the Memorized Sensors

=> (F4) => (F1)

This mode displays the number of the current sensor (currently valid) and
provides access to the following menus:

(F1)Modification of current sensor parameters.
(F2)Visualization of current sensor parameters.
(F3)Choosing another current sensor.
(F5)Return to main menu.

7.4.1.1 Selecting the Number of the Current Sensor

=> (F4) => (F1) => (F3)

From this menu, it is possible to modify the number of the current sensor.

The display then takes into account the parameters associated with the
number of the current sensor.

(F2)Previous number (-1).
(F3)Next number (+1).
(F4)Visualization of parameters of the sensor envisaged.
(F5)Save the new configuration.

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LDS1000 Controller for Laser Diode Sensors

7.4.1.2 Modification of Current Sensor Parameters

=> (F4) => (F1) => (F1)

Each NEWPORT sensor is delivered with a calibration certificate which
enables the correct programming parameters for the LDS1000 Controller to
be established.

This certificate gives the values of the following parameters:
S/N: Series number of the optical head.
A number is allocated to each sensor. It means it can be identified and its

progress can be monitored.
Type: Y axis horizontal (TR) or vertical (RT).
This indication specifies the type of measurements carried out by the sen-

sor. Thus RT, for rotation designates an autocollimator. This value is used
by some programs for a correct display.

Ycoef, Zcoef: Linear correction factor for the axis Y or Z.
The sensor can be calibrated on a measuring bench. The given value of

Ycoef or Zcoef minimizes linear errors in the direction concerned. It is a
multiplying factor of the display.

Yincr, Zincr: Counter increment for the axis Y or Z.
The resolution of each sensor is limited by physical factors (electronic

noise, enlargement, etc.). The value of Yincr or Zincr given is adapted to
the sensor delivered. It is a multiplying factor of the display.

Different measurement limits correspond to each increment value:

Yunit, Zunit: Unit displayed for the axis Y or Z.
It is the unit for which the sensor parameters are established.
Yofs1, Yofs2, Zofs1, Zofs2: Electric offset values.
These values enable the sensor resolution to be refined while taking into

account a possible offset reading. The correct values are achieved in

mode.

In mode the values of the parameters stored for the current sensor
can be modified. As a precaution, a confirmation message asks whether
you really want to modify the current sensor (and specifies the number):

0.1 -199.99 … +199.99

0.2 -399.98 … +399.98

0.5 -999.95 … +999.95
1 -1999.9 … +1999.9
2 -3999.8 … +3999.8

5 -9999.5 … +9999.5
10 -19999 …+19999
20 -39998 …+39998
50 -99995 …+99995

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LDS1000 Controller for Laser Diode Sensors

For all the parameters, a modification menu uses the following functions:

(F1)Scrolling of possible parameters (or cursor movement).
(F2)Lower value (-1 for digital values).
(F3)Next highest value (+1 for digital values).
(F4)Next parameter.
(F5)Save and exit mode.

List of parameters:

The values displayed on the screen of the controller are obtained by the
following calculation:

Y

Displayed

=

Y

Calculated

x(Ycoef x10 xYincr)

10

Z

Displayed

=

Z

Calculated

x(Zcoef x10 xZincr)

10

Designation Available Values Default Value

S/N Series number of 6 digits: 000000

the optical head 000000 à 999999

Type Sensor type Y axis horizontal (TR) RT

or vertical (RT)

Ycoef Linear correction 5 digits: 04000

factor for Y axis 00100 to 29999

Yincr Counter increment 0.1; 0.2; 0.5; 1; 2; 5; 1

for Y axis 10; 20; 50

Yunit Unit displayed µrad; sec; mrad; nm; unit

for Y axis µm; mm; unit

Yofs1 Electric offset 5 digits: 00000
Yofs2 values for Y 00000 to 32767
Zcoef Linear correction 5 digits: 04000

factor for Z axis 00100 à 29999

Zincr Counter increment 0.1; 0.2; 0.5; 1; 2; 5; 1

for Z axis 10; 20; 50

Zunit Unit displayed µrad; sec; mrad; nm; unit

for Z axis µm; mm; unit

Zofs1 Electric offset 5 digits: 00000
Zofs2 values for Z 00000 to 32767

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LDS1000 Controller for Laser Diode Sensors

7.4.1.3 Display of Result in Arc-Seconds (LDS-Vector)

=> (F4) => (F1) => (F1)

The calibration certificate gives the values Ycoef, Zcoef, Yincr and Zincr for
result display in µrad. In general, Yincr and Zincr are equal to 1. The resolu­tion of the display is then 0.1 µrad.

To display the result in arc-sec:

1 arc-sec = 4.85 µrad

1 µrad = 0.2062 arc-sec

Thus: Y µrad = (0.20 x1.0309 xY) arc-sec

Thus we will use the increments Yincr = 0.2 and Zincr = 0.2. That gives dis­play limits of -400 to + 400.

The values Ycoef and Zcoef are corrected by 1.0309:

Ycoef1= Ycoef x1.0309 (rounded to the nearest unit).

Zcoef1= Zcoef x1.0309 (rounded to the nearest unit).
The unit sec will be chosen.
You are advised not to delete the initial parameters, in µrad. You only need

to program a new sensor number.

7.4.1.4 Programming a New Sensor

When an LDS-Vector autocollimator is delivered with its electronic control­ler, the sensor parameters are fed into the memory of the controller. The
number 0 is used for the current sensor.

The other memories are normally empty, and the values of the parameters
are therefore equal to the default values.

To program a new sensor, a spare place must be found, generally recogni­zable when S/N = 000000. You can choose to delete an existing sensor.

Access to the mode that enables rapid visualization of the various heads is
obtained by the sequence:

=> (F4) => (F1) => (F3)

It is then possible to modify the number of the current sensor:

(F2)Previous number (-1).
(F3)Next number (+1).
(F4)Visualization of parameters of the sensor envisaged.
(F5)Save the new configuration.

Programming the new sensor is done by the menu (see modification
of sensor parameters).

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LDS1000 Controller for Laser Diode Sensors

7.4.1.5 Visualization of Current Sensor Parameters

=> (F4) => (F1) => (F2)

You are advised to check that the current sensor really matches the sensor
that is currently connected to the controller. This Visualization mode is
easily accessible and provides the explicit values of the current sensor
parameters.

Check that the series number really matches that of the connected sensor.
For more certainty, compare the values of the parameters to those given in
the calibration certificate supplied with the sensor.

In case of nonconformity, it is necessary to:

•Either find another number of the current sensor (especially if the
series number does not match): Menu.

•Or modify the current sensor parameters: Menu.

7.4.2 Communication Parameter Input

=> (F4) => (F2)

Access to this menu enables the parameters and the choice of communica­tion mode of the controller to be modified. It is useful to check these values
before connecting to a computer. This must be done before using the ins­trument in Interface Mode.

The menu makes this selection possible in manual mode

This message indicates that the communication is programmed in RS-232-C.
Access to the following functions is then possible:

(F1)Changing RS-232-C <=> IEEE-488.
(F2)Modification of the parameters of the selected interface.
(F3)Change to default values of the selected interface.
(F5)Return to main menu.

The communication mode can be modified from this menu using the
(F1) key.

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LDS1000 Controller for Laser Diode Sensors

7.4.2.1 Modification of RS-232-C Parameters

=> (F4) => (F2)

The RS-232-C interface is active if the display is as follows:

Otherwise, the (F1) key provides access to this menu.
In mode the values of the parameters stored for the RS-232-C interfa-

ce can be modified.
For all the parameters, a modification menu uses the following functions:

(F1)Scrolling of possible parameters (and their status).
(F4)Next parameter.
(F5)Save and exit mode.
(F5)Return to main menu.

List of parameters:

7.4.2.2 Modification of IEEE-488 Parameters

=> (F4) => (F2)

The IEEE-488 interface is active if the display is as follows:

Otherwise, the (F1) key provides access to this menu.
In mode the values of the parameters stored for the IEEE-488 interfa-

ce can be modified.
For all the parameters, a modification menu uses the following functions:

(F1)Scrolling of possible parameters (or cursor movement).
(F2)Lower value (-1 for digital values).
(F3)Next highest value (+1 for digital values).
(F4)Next parameter.
(F5)Save and exit mode.
(F5)Return to main menu.

Designation Available Values Default Value

MSG TERM End of sequence CR; LF; CR LF; LF CR CR

terminator

BAUD RATETransmission 300; 600; 1200; 2400; 9600

Speed 4800; 9600; 19200

WORD LENGTH Length of 7; 8 8

the string sended

STOP BITS Stop bit 1; 2 1

number

PARITY Parity NONE; ODD; EVEN NONE