AMO STU-20 User manual

Manual
Signal Test Unit
STU-20
Software Rev. 2.0

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Signal Test Unit STU-20

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Signal Test Unit STU-20
Table of contents
1. Contents of delivery 4
2. Installation 4
2.1. System Requirements 4
2.2. Software installation 4
2.3. Hardware installation 6
3. Connectors and displays 7
3.1. Front panel 7
3.2. Rear panel 7
4. Functional description 8
4.1. General 8
4.2. Start the program 9
4.3. Select the AMOSIN®-Type 10
4.4. Counter / Meter 12
4.5. Airgap measurement 13
4.6. Oscilloscope function 15
4.7. Signal accuracy measurement 16

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Signal Test Unit STU-20
Contents of delivery1.
The following components belongs to the STU-20:
Signal Test Unit STU-20■
Power supply 12VDC/500mA■
USB-Cable■
4 adapter cable■
1 extension cable■
Software on DC-ROM■
Installation2.
System Requirements2.1.
Operating system: Windows2000 or higher
USB-Port: USB 2.0
Display resolution: 1024 * 768 or higher
Software installation2.2.
It is strongly recommended to exit all programs before running the installer. Start
the le setup.exe located on the CD-ROM delivered together with the STU-20.

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Signal Test Unit STU-20
Initialization2.2.1
Please wait while the installer initializes.
Destination directory2.2.2
Select the installation directory for the STU-20 software components. As a
standard there is a different path for the National Instruments software. You can
select the same path as for the STU-20 software components if you like.
After that please accept the National Instruments Licence Agreement.
Finishing the installation2.2.3
After the installation has nished please restart the computer.

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Signal Test Unit STU-20
Hardware installation2.3.
After the successful installation of the software connect the STU-20 to the
computer with the USB-cable. The assistant for installation of a new hardware
appears.
Disable the connection to “Windows Update” for this hardware installation and
choose the automatic installation for the software in the next window.
To nish the installation click on the button “Finish”.
Now the STU-20 is installed completely, you can start the program using “Start-
>Programs->STU-20”.

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Signal Test Unit STU-20
Connectors and displays3.
Front panel3.1.
(1) Connector for the measurement system
Pin assignement see Chapter “Pin Assignements -> 12 pin
Connei Connector”
(2) Power-On LED
Led is on, when power supply for the measurement system is
switched on.
(3) Mounting Indicator
Additional display of the Zusätzliche Anzeige der korrekten
Montage des Messsystems (siehe Kapitel „Montagehilfe“)
(4) +5V Adjust
Potentiometer zum Einstellen der Versorgungsspannung des
Messystems auf 5,0V.
Rear panel3.2.
(1) USB-Port
(2) Connector for power supply
Supply voltage: 12 VDC/500mA

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Signal Test Unit STU-20
Functional description4.
General4.1.
The STU-20 offers the following functions:
Selection of the AMOSIN-Type which should be tested.
Indicator for the supply voltage and the current consumption, as
well as a position display for systems with TTL output signal.
Examination of the correct air gap for an mounted measuring
system.
Examination of the output signals with a built-in oscilloscope
function.

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Signal Test Unit STU-20
Start the program4.2.
The program is started over the Windows Start Menu “Start->Programs-
>STU-20”.
As a rst step the initialization of the hardware takes place.
If the STU-20 is not connected with the computer by the USB cable, the pro-
gram stops with an error message “Hardware Init Failed”.

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Signal Test Unit STU-20
Select the AMOSIN®-Type4.3.
By clicking on the button the window for selecting the AMOSIN®-type
appears.
Procedure for selection:
a) Selection of „Typ“: WMK ... Angle measuring system
LMK ... Length measuring system
b) Selection of „Signal“: 1Vss ... analog output signal
TTL ... digital output signal
c) Select the correct AMOSIN®-type from the list.
d) For angle measuring systems only:
Enter the number of pitches per revolution of the ange into the input
eld “Scale; Pitches/Rev”. Example: For a measuring system WMK-
201.10-0512-1-6 the correct Value is 512 pitches per revolution.
e) If the desired selection is done, conrm by pressing “OK”.

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Signal Test Unit STU-20
After selection of the AMOSIN® -type the data of the measurement system
appear in the upper third of the program window.
Type: selected AMOSIN®measuring system
Output: output signal type
Resolution: resolution of the output signal
Scale Pitch: grating pitch of the scale
Pitches/Rev: number of pitches per revolution

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Signal Test Unit STU-20
Counter / Meter4.4.
By clicking the button the Counter / Meter – window appears.
Supply Voltage:
Indicates the supply voltage measured on the Sense-Lines of the measurement
system. The supply voltage can be adjusted to 5.0 Volt with the potentiometer
located on the front panel of the STU-20.
On connector types without Sense-lines (9pol. Sub-D and 12pol.
DIN) the measurement indicates the voltage on the connector.
Especially on greater cable length take into account the voltage drop
on the measurement system cable and an additional extension
cable.
Current:
Indicates the current consumption of the measurement system.
Position display:
The position display indicates the position in degrees for angle measurement
systems or in mm for length measuring systems.
By clicking on the „Res“-Button the display can be set to zero.

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Signal Test Unit STU-20
Airgap measurement4.5.
By clicking the button the window for the examination of the correct air-
gap appears.
General4.5.1
With this Tool the correct value of the air gap can be examined. The adherence
to other assembly tolerances such as axial disalignment or parallelism betwenn
scale and measuring head cannot be examined (these tolerances are usually
given by the construction of the mechanics and cannot not be affected by the
assembling of the measuring system).
This tool cannot be used for the following measurement system types:
measurement systems with serial numbers, where the last 3 digits are■
less than 230 (e.g.: SN: 0601234-212).
measurement systems with limit switch function■
measurement systems without limit switch pins (LL u. LR) available on■
the connector (e.g.: 12pol. Din-connector, 9pol. Sub-D-connector or
connectors with special pin assignements).
following measurement systems:■
WMK-x02.A-xxxx
WMK-x02.B-xxxx

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Signal Test Unit STU-20
Measurement procedure4.5.2
The measurement procedure is started by clicking the button „Start Test“.
Afterwards the axis must moved or turned continuously into a direction. After a
movement of approx. 60mm the determined airgap is indicated graphically on
the monitor and by the indicator LED at the front panel of the STU-20.
The different colored areas can be interpreted as follows:
the green area symbolizes a mounting within the half airgap tolerance;■
Indicator LED shines continuously.
The yellow area symbolizes a mounting within the airgap tolerance;■
Indicator LED is ashing.
The red area symbolizes a mounting out of the airgap tolerance;■
Indicator LED is dark
It is recommended to adjust the measuring system in such a way that the airgap
lies over the entire possible movement of the axis within the green range.

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Signal Test Unit STU-20
Oscilloscope function4.6.
By clicking on the button the oscilloscope winow appears.
The oscilloscope can be used for the examination of the output signals of the
measurement system.
Functionality:
Timebase and Amplitude adjustable in steps.■
Trigger function to trigger on the reference signal■

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Signal Test Unit STU-20
Signal accuracy measurement4.7.
By clicking on the button the signal accuracy winow appears.
General4.7.1
With this tool the signal accuracy can be examined. That means this measure-
ment takes into account all mechanical deviations from ideal mounting.
Measurement procedure4.7.2
After starting the measurement the axis has to be moved with uniform speed
as best as possible. When the movement was done with uniform speed for a
certain number of periods the data aquisition stops and the signal accuracy will
be evaluated and displayed.
The necessary uniformity of speed to trigger the aquisition can be adjusted
using the knob „Achievable uniformity of speed“.
The number of signal periods (i.e. the necessary length of movement that has to
be done with uniform speed) can be adjusted using the knob „Measuring length
for data aquisition“
Lowering the measuring length and uniformity of speed increases the uncertain-
ty of measurement.

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Signal Test Unit STU-20
By activating the button „Reference“ the measurment can be triggered on the
reference signal of the encoder.
Interpretation of the measuring results4.7.3
The measured signal accuracy will be displayed at the bar graph „System accu-
racy“.
Results higher than 0,7 indicates a high signal accuracy.
Results inbetween 0,7 and 0,4 indicates that signal accuracy is good but can be
increased by improving the mechanical mounting conditions.
Results less than 0,4 indicates a low signal accuracy maybe caused by moun-
ting conditions that are out of tolerance.
The interpretation of the measuring results can differ from that stated above and
depends on the type of axis, kind of drive etc.

A-4963 St. Peter am Hart, Nöng 4 - Austria
Phone: [phone] - 0
Fax: [phone]
email: of[email protected]
www.amo-gmbh.com
AMO GmbH
SN: M_STU-20_V2.0_20090504