heop sine bar by mikeholy


									       Interfacing the Hewlett Packard HP 54603B 60 MHz
  Oscilloscope to the PC Using LabVIEW and the GPIB Bus

                Avraham Semenkee, and Ralph & Rachel Rosenbaum
  Tel Aviv University, School of Physics and Astronomy, Ramat Aviv. 69978


    National Instruments has not written a specific driver software program to interface our HP
54603B Oscilloscopes to the PC’s. However, there are some general “Icons” interfacing
“subroutines” for the general HP series of 546XX scopes.

    Avraham has spent lots of time figuring out how to use some of these special icons and we
give you hints and suggestions on how to use them to “communicate” to the scope.

    First, review the notes entitled “LabVIEW Manual”. In these notes, we explain how to
communicate with the Hewlett Packard Digital MultiMeter (DMM) the HP 34401a. We’ll use
lots of the steps that were introduced in the first few pages of these notes.

    Second, review the front panel operations of the scope. Refer to the introductory and useful
HP book entitled “User and Service Guide” and get familiar with the scope by using the special
scope “kit”, the HP 54654A and its instruction book. This “kit” is a self-paced training kit for
the HP 54600 series of oscilloscopes. We always forget how to use the scopes after an one year “
time break” of no use; and spending a couple of hours to familiarize yourself with the scope’s
operation is time well invested.

    Be sure that the GPIB cable is connected between the scope and the National Instrument
GPIB card attached to the PC motherboard. The GPIB address of the scope is 14, and to our
knowledge cannot be changed.

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    The following “Front Panel” and “Block Diagram” show Avraham’s program that will
measure a sine wave signal connected to Channel 1 of the HP 54603 B 60 MHz oscilloscope.
Note that the sine wave is displayed on a screen or “Waveform Graph” that appears on the
“Front Panel”. Also the individual digitized readings can be read out. Again the major problem
is locating the useful icons that are needed for the “Block Diagram”. We now give the details.

                                           “Front Panel”

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    Controls and Indicators:

        Channel (chan1:0)
        The channel selector selects the channel to configure’
        0 – channel 1
        1 – channel 2

        coupling (AC:0)
        The coupling selector selects the input coupling for the specified channel.
        0 – AC
        1 – DC
        2 – ground

        The range selector defines the full-scale vertical axis of the selected channel. It can be set
        to any value from 16 mV to 40 V when using the 1:1 probe. If the probe value is changed,
        the range is multiplied by the attenuation factor.
        The position selector sets the voltage that is represented at the center screen for the
        selected channel. The range of the possible values varies with the RANGE command. If
        the position value is set outside of the Range, then it is automatically set to the nearest
        legal value.
        Range time
        Sets the full-scale horizontal time in seconds. It is ten times the time per division. When
        the delay timebase is selected, the RANGE command will set the full-scale horizontal
        time of the delayed timebase.
        Mode (normal:0)
        This command sets the time base mode:
                 normal:    the main timebase, also the default timebase.
                 delayed: the range and delay commands set the values in the delayed timebase
                            instead of the main timebase. No waveform data is available through
                            the bus.
                 XY:        Range, Delay, and Reference commands not available.

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    The volts measurements ring selects the desired voltage measurement to be taken.

    0 - V p-p
    1 – V average
    2 - V rms
    3 – V max
    4 – V min
    5 – V top
    6 – V base
    7 – frequency
    8 – period
    9 – duty cycle
    10 – positive width
    11 – negative width
    12 – rise time
    13 – fall time
    function reading
    The function indicator reads back the selected measurement.
    A +9.9E+37 is returned if the measurement cannot be made.

                                           “Block Diagram”

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A. Finding the first icon, the: HP54600A          icon; and also the   HP546XXB      icon.
                                    CHANNEL                            CONF TIME

    1. a) Go to the “Function” BAR on the top of the screen and click on the WINDOW
        b) In the drop-down table, click on the entry “Show Functions Palette”;
        c)   Select the 5th (fifth) icon on the LEFT hand side of the new drop-down
             table – this icon is entitled ”Instrument I/O”;
        d) You now get a second new drop-down table entitled “Instrument I/O”;
             note that there are five icons that appear in this table. Choose the icon
             located in the UPPER LEFT hand side – this icon is entitled “Instr/Lib”;
        e)   Again we get a third new drop down table entitled “Instrument Drivers”;
             in this table appear 7 icons, 4 icons located in the upper row and 3 icons
             located in the lower row. Choose the icon located in the UPPER
             RIGHT hand side – it is entitled “HP546XXX VIs”;
        f)   f) Still another drop-down table called “HP546XXX VIs” appears. In this
             table, notice that there are three icons in the top row and four icons in the
             bottom row. We will use two of the four icons in the bottom row, the
             “Configure” Icon located on the BOTTOM LEFT hand side and the
             “Data” Icon located on the BOTTOM and THIRD LOCATION from
             the left hand side. Meanwhile, select only the “Configure” Icon at this
        g) Wee, now the last drop-down table appears with the name “Configure
             VI’s”. In this table there are many icons, in fact in the top row there are 9
             icons, in the middle row also 9 icons and in the bottom row, maybe 8 or
             9 icons also. Go to the icon located in the UPPER LEFT hand side; it is
             entitled “HP54600A Channel Config.vi” Icon. Drag this icon onto the
             “Block Diagram”. This icon is identified by the label “HP54600A and
             has a little picture of a scope inside it.
             At the same opportunity, go to the icon on the BOTTOM ROW and 5th from the left
             hand side. It is entitled “Time Base Config.VI”; drag it too onto the “Block
             Diagram”. This second Icon is identified by the label “HP546XXB, a picture of a
             little hand clock and CONF TIME” all inside it. See the Block Diagram for details.

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   2.   “Initializing or Setting Up” the first icon, the “HP54600A Channel Config.vi” Icon:
        a) Input steps: Using the drop-down menu by clicking on this icon you
             will wish to introduce some initialization steps that will appear on
             the “Front Panel”. Referring to earlier LabVIEW Manual, use the
             Create button  Control button and the various input terminals on
             this icon to program these items:
              1) VISA Session and on the front panel, write into the
                   VISA         session      window      the         following:
                   GPIB0::14::INSTR . Here the “zero” after the GPIB
                   refers to the address of the GPIB card located on the
                   mother board. The number 14 is the GPIB address of
                   the scope.
              2) Channel.
              3) Coupling.
              4) Range.
              5) Position (that is, the vertical offset of the base line).

        b) Output steps: Connect up the “Error” wire between the two icons as
             well as the “VISA session” wire between the two icons using the
             “wiring tool or spool”.

   3.   Initializing or setting up the second icon, the “HP546XXB TIME BASE Config. VI” Icon
        (this icon has a picture of an alarm clock in its center):
        a) Input steps:
              1) Check that the “VISA Session” wire is connected from
                   the first icon.
              2) Is the “Error” cable connected from the first icon?
              3) Set a value for the “Range Time” (which is TEN times
                   the time per division).
              4) Set the “Mode”.
        b) Output steps:
              1) “dup (duplicate) VISA Session” using new wire to a
                   new third icon, the “Read Waveform.vi” Icon (which
                   we’ll tell you about shortly).

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              2) Error out using a new wire to this “Read
                   Waveform.vi” Icon.

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B)    Setting up the third icon, the “HP54600A/610B Read Waveform.vi”. This icon goes to the
      RAM storage buffer memory in the scope and reads the 1000 digitized measured values of
      the input signal (connected to Channel 1). To find this icon, go back to Page 5 and go back
      to step “1.f”. We now call up the third icon, the “Data” Icon that appears in the BOTTOM
      THIRD LOCATION from the left hand side of the dialog box with the name
      “HP546XXX.VIs”. Click on this icon. Find the icon that looks like this:

                                                                                    READ WAVE

      The full name of this icon is: “HP54600A/610B Read Waveform.vi”. Drag this icon onto
      the “Block Diagram”.

      Again, check that you have connected inputs that include these two wires:
                  dup VISA Session

      Also, we need to select the channel that we read: “read source (Chan1:0)”.

C)    Finally, we need to display the digitized data on a “scope screen” using the “Waveform”
      icon that APPEARS on the “Front Panel” and not on the “Block Diagram”. Use these

      1)       Let’s go to the “Front Panel” by clicking on the little button labeled “Window”.
               This button is located on the Procedure BAR at the top of the monitor screen. In the
               drop-down box, click on “Show Panel”. The “Front Panel” should now appear on
               your monitor screen.

      2)       Again. go back to the little button labeled “Window” on the Procedure BAR. Again
               chick on “Window” to get the same drop-down box and this time choose the “Show
               Panel Palette” You will now get a drop-down or dialog box that has lots of icon
               symbols arranged in three long vertical columns. This drop-down box has the name
               “CONTROLS” but the name is very misleading since it also includes “Indicators”,
               namely OUTPUT devices, as well as input devices or controls. Choose the icon
               located in the THIRD COLUMN (the column on the RIGHT hand side) and on the
               SECOND ROW; this icon should resemble a scope screen:                    Click on it.

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      We again get another drop-down box with the name “Graph”. Again it contains many
      icons arranged in three vertical columns. Go to the icon located on the VERY TOP
      CENTER column. It should have the name “Wave Form Graph”. If so, drag it onto the
      “Front Panel” screen. You will need to play a lot with this scope screen to program its “x”
      or horizontal axis with the correct magnitude range as well as to program its “y” or vertical
      axis with the correct magnitude range.

D)    Lastly, you might like to read out the individual digitized readings. To do so, you will need
      to add an “Output” indicator to the front panel. Go to the last icon, the “READ WAVE”
      icon and using the CREATE and INDICATOR buttons, add an “Output” indicator to the
      front panel. When you run the program, you will have 1000 readings that you can select
      from this “Output” display.

Run the program. We hope it works. If so, you can add many other features.

     For example, the most important task is to export to a floppy disk or the hard disk of the
computer the 1000 quantized readings that the scope has stored in its internal memory. Again,
this is a very non trivial job, as it took Avraham several days of hard work to discover the
procedure! The problem is the structure of each quantized data point. Look carefully at one of
the 1000 data points found in the “Output” window that appears on your “Front Panel”.
Referring to Page 2 on the “Front Panel”, we see that there are actually three items displayed for
each data point: (a) the actual voltage reading; (b) the time of the point t(n) where n ranges from
0 < n < 999; and lastly, (c) the time “gap” or time “interval” d (d stands for DELTA  )
between each sampled point (not a very useful value to know!). In the “Front Panel” of Page 2,
the voltage reading is –0.07812 volts, taken at the time of -.001 seconds, and the time interval t
 d is 0.000004 seconds or 4 s. This implies that the next sampled point will be taken at the
time of -.000996 s. But we are really only interested in the 1000 voltage readings, so we must
separate and throw out the different time values and the same t interval that appears 1000
times. Otherwise, the icon that transfers raw data to the floppy disk or to the hard disk will be
confused. Thus, we use a special icon, called the “UNBUNDLE” Icon to do this task.

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    To find the “UNBUNDLE” Icon, return to the READ WAVE Icon on your “BLOCK
DIAGRAM” and click on the “WAVE FORM” terminal, located on the right hand side of the
icon. You should get a drop-down table that looks like this:

                                       Visible Items
                                       Description and Tip
                                       Set Breakpoint
                                       Cluster Tools
                                       Array Tools

        Click on the “Cluster Tools” button to get still this new drop-down table:

                                           Cluster Tools


                  Click on the TOP
                   LEFT hand icon
                 labeled “Unbundle”

and “drag” the “Unbundle” Icon onto your “BLOCK DIAGRAM”. Now connect up the wiring
between the “READ WAVE” Icon to this new “Unbundle” Icon. There are three output
terminals on our “Unbundle” Icon: (a) Component 0 that corresponds to the time t of the reading;
(b) Component 1 that corresponds to t  d (for Delta); and (c) Component 2 that outputs the
1000 different voltage readings. Wee, now we can export our 1000 readings to a useful storage
device using this “Component 2” terminal!

    We need to locate the Icon “Write to Spreadsheet File.vi”. Go to the “Function” BAR on
the top of the screen and click on the “Windows” button. Choose the “Function” palette to get a
drop-down table having three columns of icons. Go to the icon located on the THIRD COLUMN
(RIGHT hand side) and on the THIRD row. This icon is labeled “FILE I/O”. Click on it to get

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the following drop-down table entitled “FILE I/O”. This table contains six columns and three
rows. Go to the first icon located on the UPPER LEFT hand corner (FIRST COLUMN on
LEFT hand side and FIRST row). Choose this icon and drag it onto the “BLOCK DIAGRAM”.
Connect a wire between the “Component 2” terminal of the “Unbundle” icon and the input data
terminal of the “Write to Spreadsheet File” icon. You’ll need to add more details to this icon,
specifying where you wish to send the data.

        Actually, not only do we wish to save the 1000 voltage data points, but we also want to
have the 1000 different times, both saved in an array having two-column array and 1000 rows.
We have not figured out how to do this task at this writing, but maybe you will succeed.

            File I/O

                                                      File I/O
                                           Write to Spreadsheet File.vi

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