Schedule 13G                                                         Page 1 of 7


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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                              (AMENDMENT NO. SIX )*


                        NATIONAL INSTRUMENTS CORPORATION
--------------------------------------------------------------------------------
                                (Name of Issuer)


                                  COMMON STOCK
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    636518 10
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                DECEMBER 31, 2001
--------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

[ ]  Rule 13d-1(b)

[ ]  Rule 13d-1(c)

[X]  Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



Schedule 13G                                                         Page 2 of 7

CUSIP No.   636518   10
--------------------------------------------------------------------------------

      1.   Names of Reporting Persons, I.R.S. Identification Nos. of above
           persons (entities only).

           L. WAYNE ASHBY
--------------------------------------------------------------------------------

      2.   Check the Appropriate Box if a Member of a Group (See Instructions)

           (a) [ ]

           (b) [ ]
--------------------------------------------------------------------------------

      3.   SEC Use Only
--------------------------------------------------------------------------------

      4.   Citizenship or Place of Organization  UNITED STATES OF AMERICA
--------------------------------------------------------------------------------
Number of        5.    Sole Voting Power    2,575,982
Shares          ----------------------------------------------------------------
Beneficially     6.    Shared Voting Power  0
Owned by        ----------------------------------------------------------------
Each             7.    Sole Dispositive Power    2,575,982
Reporting       ----------------------------------------------------------------
Person With      8.    Shared Dispositive Power  0
--------------------------------------------------------------------------------
      9.  Aggregate Amount Beneficially Owned by Each Reporting Person 2,575,982
--------------------------------------------------------------------------------

     10.  Check if the Aggregate Amount in Row (11) Excludes Certain Shares
          (See Instructions)
--------------------------------------------------------------------------------

     11.  Percent of Class Represented by Amount in Row (11)     5.0%
--------------------------------------------------------------------------------
     12.  Type of Reporting Person (See Instructions)

          IN
--------------------------------------------------------------------------------



Schedule 13G                                                         Page 3 of 7


                          INSTRUCTIONS FOR SCHEDULE 13G

INSTRUCTIONS FOR COVER PAGE

(1)      Names and I.R.S. Identification Numbers of Reporting Persons -- Furnish
         the full legal name of each person for whom the report is filed--i.e.,
         each person required to sign the schedule itself--including each member
         of a group. Do not include the name of a person required to be
         identified in the report but who is not a reporting person. Reporting
         persons that are entities are also requested to furnish their I.R.S.
         identification numbers, although disclosure of such numbers is
         voluntary, not mandatory (see "SPECIAL INSTRUCTIONS FOR COMPLYING WITH
         SCHEDULE 13G" below).

(2)      If any of the shares beneficially owned by a reporting person are held
         as a member of a group and that membership is expressly affirmed,
         please check row 2(a). If the reporting person disclaims membership in
         a group or describes a relationship with other persons but does not
         affirm the existence of a group, please check row 2(b) [unless it is a
         joint filing pursuant to Rule 13d1(k)(1) in which case it may not be
         necessary to check row 2(b)].

(3)      The third row is for SEC internal use; please leave blank.

(4)      Citizenship or Place of Organization--Furnish citizenship if the named
         reporting person is a natural person. Otherwise, furnish place of
         organization.

(5)-(9), Aggregate Amount Beneficially Owned by Each Reporting Person,
   (11)  Etc.--Rows (5) through (9) inclusive, and (11) are to be completed in
         accordance with the provisions of Item 4 of Schedule 13G. All
         percentages are to be rounded off to the nearest tenth (one place after
         decimal point).

(10)     Check if the aggregate amount reported as beneficially owned in row (9)
         does not include shares as to which beneficial ownership is disclaimed
         pursuant to Rule 13d-4 [17 CFR 240.13d-4] under the Securities Exchange
         Act of 1934.

(12)     Type of Reporting Person--Please classify each "reporting person"
         according to the following breakdown (see Item 3 of Schedule 13G) and
         place the appropriate symbol on the form:



                                   Category                              Symbol
                                                                      
         Broker Dealer                                                       BD
         Bank                                                                BK
         Insurance Company                                                   IC
         Investment Company                                                  IV
         Investment Adviser                                                  IA
         Employee Benefit Plan, Pension Fund, or Endowment Fund              EP
         Parent Holding Company/Control Person                               HC
         Savings Association                                                 SA
         Church Plan                                                         CP
         Corporation                                                         CO
         Partnership                                                         PN
         Individual                                                          IN
         Other                                                               OO


Notes:   Attach as many copies of the second part of the cover page as are
         needed, one reporting person per page.

         Filing persons may, in order to avoid unnecessary duplication, answer
         items on the schedules (Schedule 13D, 13G or 14D1) by appropriate cross
         references to an item or items on the cover page(s). This approach may
         only be used where the cover page item or items provide all the
         disclosure required by the schedule item. Moreover, such a use of a
         cover page item will result in the item becoming a part of the




Schedule 13G                                                         Page 4 of 7

         schedule and accordingly being considered as "filed" for purposes of
         Section 18 of the Securities Exchange Act or otherwise subject to the
         liabilities of that section of the Act.

         Reporting persons may comply with their cover page filing requirements
         by filing either completed copies of the blank forms available from the
         Commission, printed or typed facsimiles, or computer printed
         facsimiles, provided the documents filed have identical formats to the
         forms prescribed in the Commission's regulations and meet existing
         Securities Exchange Act rules as to such matters as clarity and size
         (Securities Exchange Act Rule 12b-12).

              SPECIAL INSTRUCTIONS FOR COMPLYING WITH SCHEDULE 13G

Under Sections 13(d), 13(g), and 23 of the Securities Exchange Act of 1934 and
the rules and regulations thereunder, the Commission is authorized to solicit
the information required to be supplied by this schedule by certain security
holders of certain issuers.

Disclosure of the information specified in this schedule is mandatory, except
for I.R.S. identification numbers, disclosure of which is voluntary. The
information will be used for the primary purpose of determining and disclosing
the holdings of certain beneficial owners of certain equity securities. This
statement will be made a matter of public record. Therefore, any information
given will be available for inspection by any member of the public.

Because of the public nature of the information, the Commission can use it for a
variety of purposes, including referral to other governmental authorities or
securities self-regulatory organizations for investigatory purposes or in
connection with litigation involving the Federal securities laws or other civil,
criminal or regulatory statutes or provisions. I.R.S. identification numbers, if
furnished, will assist the Commission in identifying security holders and,
therefore, in promptly processing statements of beneficial ownership of
securities.

Failure to disclose the information requested by this schedule, except for
I.R.S. identification numbers, may result in civil or criminal action against
the persons involved for violation of the Federal securities laws and rules
promulgated thereunder.

                              GENERAL INSTRUCTIONS

A.       Statements filed pursuant to Rule 13d-1(b) containing the information
         required by this schedule shall be filed not later than February 14
         following the calendar year covered by the statement or within the time
         specified in Rules 13d-1(b)(2) and 13d2(c). Statements filed pursuant
         to Rule 13d-1(c) shall be filed within the time specified in Rules
         13d-1(c), 13d-2(b) and 13d-2(d). Statements filed pursuant to Rule
         13d-1(d) shall be filed not later than February 14 following the
         calendar year covered by the statement pursuant to Rules 13d-1(d) and
         13d-2(b).

B.       Information contained in a form which is required to be filed by rules
         under section 13(f) (15 U.S.C. 78m(f)) for the same calendar year as
         that covered by a statement on this schedule may be incorporated by
         reference in response to any of the items of this schedule. If such
         information is incorporated by reference in this schedule, copies of
         the relevant pages of such form shall be filed as an exhibit to this
         schedule.

C.       The item numbers and captions of the items shall be included but the
         text of the items is to be omitted. The answers to the items shall be
         so prepared as to indicate clearly the coverage of the items without
         referring to the text of the items. Answer every item. If an item is
         inapplicable or the answer is in the negative, so state.



Schedule 13G                                                         Page 5 of 7


ITEM 1.

       (a)    National Instruments Corporation

       (b)    11500 North Mopac Expressway, Building B
              Austin, TX  78759

ITEM 2.

       (a)    L. Wayne Ashby

       (c)    11500 North Mopac Expressway, Building B
              Austin, TX  78759

       (c)    U.S.A.

       (d)    Common Stock

       (e)    N/A

ITEM 3.   IF THIS STATEMENT IS FILED PURSUANT TO SECTIONS 240.13d-1(b) OR
          240.13d-2(b) or (c), CHECK WHETHER THE PERSON FILING IS A:

       (a) [ ] Broker or dealer registered under section 15 of the Act
               (15 U.S.C. 78o).

       (b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

       (c) [ ] Insurance company as defined in section 3(a)(19) of the Act
               (15 U.S.C. 78c).

       (d) [ ] Investment company registered under section 8 of the Investment
               Company Act of 1940 (15 U.S.C. 80a-8).

       (e) [ ] An investment advisor in accordance with Section
               240.13d-1(b)(1)(ii)(E);

       (f) [ ] An employee benefit plan or endowment fund in accordance with
               Section 240.13d-1(b)(1)(ii)(F);

       (g) [ ] A parent holding company or control person in accordance with
               Section 240.13d-1(b)(1)(ii)(G);

       (h) [ ] A savings associations as defined in Section 3(b) of the Federal
               Deposit Insurance Act (12 U.S.C. 1813);

       (i) [ ] A church plan that is excluded from the definition of an
               investment company under section 3(c)(14) of the Investment
               Company Act of 1940 (15 U.S.C. 80a-3);

       (j) [ ] Group, in accordance with Section 240.13d-1(b)(1)(ii)(J).

ITEM 4.    OWNERSHIP

Provide the following information regarding the aggregate number and percentage
of the class of securities of the issuer identified in Item 1.


                                                                          
       (a)    Amount beneficially owed:   2,575,982*

       (b)    Percent of class:  5.0%

       (c)    Number of shares as to which the person has:

              (i)   Sole power to vote or to direct the vote   2,575,982*

              (ii)  Shared power to vote or to direct the vote   0

              (iii) Sole power to dispose or to direct the disposition of    2,575,982*

              (iv)  Shared power to dispose or to direct the disposition of   0



* Includes 2,024 Shares underlying Options exercisable within 60 days of
December 31, 2001, but excludes 958 Shares held by reporting person's spouse.



Schedule 13G                                                         Page 6 of 7


Instruction. For computations regarding securities which represent a right to
    acquire an underlying security see Section 240.13d3(d)(1).

ITEM 5.    OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

If this statement is being filed to report the fact that as of the date hereof
the reporting person has ceased to be the beneficial owner of more than five
percent of the class of securities, check the following [ ].

Instruction: Dissolution of a group requires a response to this item.

ITEM 6.    OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

If any other person is known to have the right to receive or the power to direct
the receipt of dividends from, or the proceeds from the sale of, such
securities, a statement to that effect should be included in response to this
item and, if such interest relates to more than five percent of the class, such
person should be identified. A listing of the shareholders of an investment
company registered under the Investment Company Act of 1940 or the beneficiaries
of employee benefit plan, pension fund or endowment fund is not required.

ITEM 7.    IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
           THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

If a parent holding company has filed this schedule, pursuant to Rule
13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the
identity and the Item 3 classification of the relevant subsidiary. If a parent
holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule
13d-1(d), attach an exhibit stating the identification of the relevant
subsidiary.

ITEM 8.    IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

If a group has filed this schedule pursuant to Section 240.13d-1(b)(1)(ii)(J),
so indicate under Item 3(j) and attach an exhibit stating the identity and Item
3 classification of each member of the group. If a group has filed this schedule
pursuant to Section 240.13d-1(c) or Section 240.13d-1(d), attach an exhibit
stating the identity of each member of the group.

ITEM 9.    NOTICE OF DISSOLUTION OF GROUP

Notice of dissolution of a group may be furnished as an exhibit stating the date
of the dissolution and that all further filings with respect to transactions in
the security reported on will be filed, if required, by members of the group, in
their individual capacity. See Item 5.

ITEM 10.   CERTIFICATION

         (a)      The following certification shall be included if the statement
                  is filed pursuant to Section 240.13d-1(b):

                  By signing below I certify that, to the best of my knowledge
                  and belief, the securities referred to above were acquired and
                  are held in the ordinary course of business and were not
                  acquired and are not held for the purpose of or with the
                  effect of changing or influencing the control of the issuer of
                  the securities and were not acquired and are not held in
                  connection with or as a participant in any transaction having
                  that purpose or effect.

         (b)      The following certification shall be included if the statement
                  is filed pursuant to Section 240.13d-1(c):

                  By signing below I certify that, to the best of my knowledge
                  and belief, the securities referred to above were not acquired
                  and are not held for the purpose of or with the effect of
                  changing or influencing the control of the issuer of the
                  securities and were not acquired and are not held in
                  connection with or as a participant in any transaction having
                  that purpose or effect.




Schedule 13G                                                         Page 7 of 7


                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.



                                                       February 14, 2002
                                             -----------------------------------
                                                           Date

                                                      /s/ L. WAYNE ASHBY
                                             -----------------------------------
                                                          Signature

                                                    L. Wayne Ashby, Director
                                             -----------------------------------
                                                          Name/Title

The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is signed
on behalf of a person by his authorized representative other than an executive
officer or general partner of the filing person, evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement; provided, however, that a power of attorney for this purpose
which is already on file with the Commission may be incorporated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Section 240.13d-7 for other
parties for whom copies are to be sent.

ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSIONS OF FACT CONSTITUTE FEDERAL
           CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)