Interfacing the Hewlett Packard HP 54603B 60 Mhz

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

Introduction:

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.

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.

“FrontPanel”

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

range

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.

Position

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. Itistentimesthetimeperdivision. 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.

function

(Vpp:0)

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”

A. Finding the first icon, the: icon; and also the icon.

1.a) Go to the “Function” BAR on the top of the screen and click on the WINDOW button;

b)In the drop-down table, click on the entry “Show Functions Palette”;

c)Select the 5th (fifth) icon on the LEFThand 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 LEFThand 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 RIGHThand 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 time;

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 LEFThand 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.

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 Createbutton 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 timeper 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).

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

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:

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

Error

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 steps:

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 theRIGHThand side)and on the SECOND ROW; this icon should resemble a scope screen: Click on it.

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 CENTERcolumn. 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.

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
Help
Description and Tip
Set Breakpoint
Create
Cluster Tools
Array Tools
Replace

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

ClusterTools

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(RIGHThand side)and on the THIRD row. This icon is labeled “FILE I/O”. Click on it to get 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 LEFThand corner(FIRSTCOLUMN on LEFThandside andFIRST 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.

Scope Interfacing Lab.docVersion, Feb. 2002

Functions

File I/O

Write to Spreadsheet File.vi

Scope Interfacing Lab.docVersion, Feb. 2002