Newport PM 500 Stage Tuning Manual

PM 500 Stage Tuning Manual

1 Setup

1.1 Materials Required

1. Small standard head adjustment screwdriver

2. PC interface through which to communicate with PM500, i.e. PCS

3. 10Mhz (minimum) oscilloscope with X-Y sweep mode

4. DMM (Digital Multi-Meter) with Voltmeter capability

1.2 Warm-up Controller

It is important to let the motion controller cards warm up for 15-30 minutes.
This will ensure that thermal fluctuations do not alter stage performance.

1.3 Oscilloscope Setup

1.3.1 Oscilloscope Calibration

Oscilloscopes from different manufacturers vary concerning labeling and
adjustments. The nomenclature used in this manual is applicable to all
oscilloscopes that are 30 MHz or higher, with X-Y sweep capability, and that
it can accommodate the procedures listed below.

—Note—

When performing the procedures discussed on the
following pages, power your oscilloscope from the
same outlet that powers the controllers. Take care that
the oscilloscope probe ground clips do not short any of
the components in the controller.

1. Plug into a stable, grounded (3-prong) 110 V power source, preferably
from the same source and ground that supplies the controller, such as the
power strip inside the tool.

2. Remove the ground clips from the oscilloscope probes. The ground clips
may be used if the oscilloscope has interference on the signal due to poor
grounding. The grounding clips must be used with caution to prevent them

from falling into the controller and damaging the system or shorting test
points to ground.

3. Allow a warm up period for the oscilloscope to stabilize (refer to your
oscilloscope manual).

4. Determine the probe gain (1X, 10X, etc.). Always verify that the probe
gain is taken into account when setting the oscilloscope (refer to your
oscilloscope manual).

Figure 1 Oscilloscope Calibration

5. Ensure that the probes are properly compensated by using the calibration
signal provided by the oscilloscope. This step should be accomplished
before beginning the tool calibration procedure. Adjust the probes for
sharp corners on the square wave. Verify that the calibration voltage is
displayed correctly when the variable amplitude adjustment is set in the
CAL position. Refer to your oscilloscope manual if you are not familiar
with this process.

6. Verify that the variable amplitude and frequency adjustments are set in the
CAL position.

Figure 2 Centered dot on screen

7. To setup the scope to be used in X-Y mode, set the mode to X-Y, coupling
to GND, and V/div to 1.0V/div (or .1V/div for 10X probe). Use the
horizontal and vertical position controls to center the spot on the center of
the screen. Re-verify, before adjusting each encoder, that the X-Y mode
ground reference position is at the center of the screen (some oscilloscopes
drift during warm-up and the centering may have been lost when other
scope settings were used). Failure to center the spot will cause errors in
the adjustment of the encoders.

Refer to the figures on the following pages for the location of the test points
and potentiometers The following procedures are to be used with Rev R and
later axis boards.

1.4 PCS Interface

During the tuning procedures it will be necessary to send commands to the
stages through PCS. The following are instructions on how to access the
interface through which commands are input and executed.

CAUTION

Only qualified personal should attempt to perform
stage tuning.

1. First, while in PCS, click on the Service tab at the bottom of the

screen to open the PCS Service window.

Figure 3 Service Tab Used to Open the Service Window

2. Once in the service window is open, click the button labeled

Motion Controllers.

Figure 4 Motion Controller Button in Service Window

3. Clicking the Motion Controllers button will open a new window

giving the user a choice of which motion controller he would like
access.

Figure 5 Motion Controller Selection Window

4. Clicking on one of these buttons will open up the interface window
of the selected stage.

Figure 6 Motion Controller Interface Window

5. From this window, commands can be entered in the field labeled
Command. Once a command is typed in, the yellow execute
button must be clicked to send the command to the stages. See
page back page for a list of commonly used commands.

1.5 Tuning Procedure Preliminaries

The following are procedures that should be reviewed before any tuning is
done. In some cases these preliminary procedures may eliminate any small
problems. During the tuning procedure the user will be asked to take
measurements using probes and make adjustments to trim potentiometers.
The test points and trim potentiometers lie on the individual axis boards
inside the motion controller. Throughout this document a picture of the top
part of the axis board looking from the component side where the trim
potentiometers are located will be referenced to show the user which test
point and trim potentiometer to use.

Figure 7 Top of Axis Board

The left side of the picture is the section of the axis board near the back of the
motion controller case. The right side is closer to the front of the motion
controller case.

NOTE

PM500 communication level “SCUM 1” is assumed throughout

this procedure. Input the commands indicated in this procedure

from the “Motion Controllers” button of the PCS “Service”

screen.

1. First issue a SCUM? query to the controller to ensure that correct
communications mode (SCUM1) has been setup. If the response is
“1” then SCUM1 is being used, if the response is “0” then issue a
SCUM1 command to setup the SCUM1 communications mode.

2. The next step before attempting to tune is to reset the PM 500
analog electronics to their original factory settings.

3. Input command SDEFEE and wait several seconds. The status box
should return with an “Operation Successful” response. This
command resets the PM500 analog servo electronic and motion
parameters to their default factory settings.

5. Input command SRSTART and wait several seconds. This command

resets the PM500 as would a hard reset. If this command is issued
through PCS the response through PCS will be that the “Operation
Failed”. This is normal and correct since the command reboots the
controller thus making it momentarily unavailable to GPIB queries.

NOTE

The SDEFEE and SRSTART commands should only be issued

once per controller at the beginning of the tuning processing and

not between tuning each axis board.

6. Auto-Zero the stage: Issue command <axis>AZ. Do not touch or

disturb the stage or tables during the Auto-Zero.

NOTE

Replace <axis> with the letter that corresponds to the axis

controller being tuned. For example: if tuning a 4L stage in the

Y-slot, enter YAZ as the command. The controller slots are

assigned as X Y Z A B C from left to right looking from the front

of the controller. Be sure to use the correct assigned alphabet to

avoid moving and damaging the wrong stage.

7. Wait 45 seconds until the Auto-Zero routine is complete. Then

confirm it is complete by entering the command: <axis>STAT?
and observe that the commands returns the <axis>D response. If
the stage is still busy <axis>B will be the response.

8. Once the Auto-Zero is complete, use the <axis>AZVAL?

Command to query how well the stage is finding its position.

9. Once the <axis>AZVAL? Command has been issued, PCS will

response with a number for each axis. The number will be in the form:
<axis>D$000004FF. The D signifies the Auto Zero was done, if the
Auto Zero is not finished there will be a B instead. In the number that
follows we are only interested in the last two pairs of numbers (or
letters). In this example 04 and FF are the pair in which we are
interested. These two pairs of digits tell us whether the stage is
performing properly. Another possible value would be D$0000FC03.
Below is a list of allowed values for the <axis>AZVAL? response, if
either of the last two pair of digits do not match the ones listed below,
tuning is necessary.