EXHIBIT 10.4


                               AGREEMENT REGARDING
                               TERMS OF EMPLOYMENT

     National Instruments  Corporation (the "Company") and Mihir Ravel ("you" or
"Ravel"  ) agree on the  following  terms of  employment  as of this 18th day of
April, 2000:

1.   Position. Starting April 18, 2000, Company employs Ravel in the position of
     Vice  President,  Corporate  Development at the Company's  headquarters  in
     Austin,  Texas,  reporting to the Chief Executive Officer and Ravel accepts
     such  employment.  Company shall assign such duties as are consistent  with
     Ravel's position as a Company officer and are within the scope of duties as
     defined in Attachment B hereto.  Company  shall not reassign  Ravel without
     his express written  permission.  Ravel shall devote his full-time and best
     efforts  to  his  duties  for  the  Company;  provided,   however,  Company
     acknowledges  that Ravel is assisting as a board-member or adviser (and not
     as an officer or employee) a multimedia  technology venture  ("Venture") to
     which he will devote up to1/2of  his time until  September  1, 2000.  Ravel
     shall make the Company his priority in the event of a conflict  between his
     position with the Company and the Venture.  If Ravel,  of his own volition,
     does not relocate to Austin,  Texas, on or before September 1, 2000, unless
     the Company  grants him a written  extension  to a later  relocation  date,
     Ravel  understands  that he will not be entitled to any of the remedies for
     termination  without cause/for good reason set out in paragraph six of this
     Agreement or other compensation contingent upon employment.

2.   Compensation. Company shall pay Ravel a base salary of $15,833.34 per month
     ($190,000,  if  annualized)  ("Base  Salary").  During the time Ravel works
     part-time  for the  Company,  his  salary  will be  pro-rated  for the time
     actually  worked for the Company.  National  Instruments  reviews  salaries
     twice a year.  You will be  eligible  for  your  first  merit-based  salary
     increase  April  2001.  In the event your  salary is  increased,  your Base
     Salary shall be the increased amount.

3.   Signing  Bonus,  Profit  Share.  In  addition,  you will  receive a $20,000
     signing bonus  [$10,000 (less taxes and  withholding  paid at time of hire,
     $10,000 (less taxes and withholding paid upon move to Austin)]. You will be
     eligible  for profit  sharing  which can be up to 40% of your  annual  Base
     Salary.

4.   Stock  Options.  At  the  next  regularly  scheduled  meeting  of  National
     Instruments Board of Directors after you begin employment,  management will
     recommend  that you receive an option award to purchase  100,000  shares of
     the  Company's  common stock at its fair market value on the date of grant.
     The  option  grant is  subject to the  approval  of the Board of  Directors
     Compensation  Committee,  which  approval  the  Company  shall seek in good
     faith, and except as otherwise  stated herein,  the grant is subject to the
     terms  of the 1994  Incentive  Plan,  your  continued  employment  with the
     Company and the terms and  conditions set forth in the award  agreement.  A
     summary of the 1994 Incentive  Plan has been included for your review.  The
     above  recommendation  for a stock  option  award and  additional  monetary
     compensation is contingent upon and in  consideration  for your signing our
     Employee Confidentiality Agreement.

5.   Other Benefits.

     (A)  Moving Expenses/ Housing Subsidy. A relocation package will be paid on
          your  behalf  as  outlined  in  Attachment  A. You will also be paid a
          housing subsidy of $300 per month in years one and two, $200 per month
          in year three,  and $100 per month in year four. The Company will also
          pay the realty fee incurred by you to sell your principle residence in
          Oregon, up to a maximum of 7% of the sales price.

     (B)  Vacation.  You will accrue vacation at the rate of 10 hours per month,
          and you will be eligible to earn higher levels of vacation  consistent
          with our vacation schedule.

     (C)  Benefits. The Company also provides employee medical, dental, life and
          disability  insurance,  and you will be eligible  for profit  sharing,
          participation  in the Company's  401(k)  retirement  plan and Employee
          Stock  Purchase  Plan.  A benefit  summary has been  provided for your
          review.  You will be entitled to such  insurance and other  employment
          benefits as are available to other  executive  officers of the Company
          under the same terms and conditions applicable to such other executive
          officers.

6.   Termination.  Texas is an "At Will"  employment  state.  Accordingly,  your
     employment with National  Instruments will be "At Will", is for no specific
     time period,  and can be terminated by you or National  Instruments  at any
     time,  with or without  cause or advance  notice,  subject to the severance
     obligation,  if  any,  as  provided  in  this  Agreement.  This  "At  Will"
     employment  relationship  will  remain in effect for the  duration  of your
     employment and can only be modified by an express written contract,  signed
     by you and an authorized representative of National Instruments.

     (A)  For  Cause/Voluntary  Resignation.  The  Company  may  terminate  this
          Agreement and your employment  immediately for "Cause" as that term is
          defined here.  "Cause" means any one of the following:  (a) conviction
          of a felony;  (b) material  misappropriation  of Company  assets,  (c)
          fraud  towards  the  Company;  (d)  material  breach  of the  Employee
          Confidentiality Agreement; (e) the Employee engages in insubordination
          that continues for 30 days after Employee receives written notice from
          the   Company    specifically    stating   the   facts    constituting
          insubordination,  excessive  absenteeism  not  arising  from  illness,
          violation of any state or federal law prohibiting sexual, race, gender
          or other  harassment  of employees or  customers;  or (f) the Employee
          becomes  physically  or  mentally  disabled  and  cannot  perform  the
          essential functions of his position with reasonable  accommodation for
          a period of 90 days. In the event of  termination  for Cause or if you
          voluntarily  resign your position  without "Good Reason," as that term
          is defined  below,  the Company  will pay you your Base Salary and any
          earned bonus and profit share through the date of termination.

     (B)  Without Cause /For Good Reason. If the Company  terminates you without
          Cause or if you  resign  with Good  Reason,  as that  term is  defined
          below,  the Company shall  immediately  do the following (i) pay you a
          lump sum severance equal to one year's  then-current Base Salary, and,
          (ii) as soon as practicable after receiving  documentation,  reimburse
          you for the  reasonable  expenses you incur moving you and your family
          from  Austin  back to  Portland,  Oregon or to such other  destination
          within the Continental United States as you may specify.  In addition,
          in the event the  termination  without Cause or  resignation  for Good
          Reason occurs prior to the third  anniversary  date of this Agreement;
          (a) all  outstanding  unvested  stock  options you hold that, by their
          terms,  would  otherwise vest within the twelve (12) months  following
          the termination  date, up to a maximum of thirty-six (36) months total
          vesting  from  the  date  of  employment,  shall  vest  and  be  fully
          exercisable  as of the  termination  date and (b) Company shall change
          your  status  from  employee  to  consultant  to  the  Company  for  a
          continuous  period of three years from and after the termination date.
          During the consulting period,  you shall provide  consulting  services
          equivalent to one week per year,  compensated  at an hourly rate equal
          to twice your  applicable  Base Salary  divided by 2080 hours.  On the
          termination   date,  all  remaining   options,   that  have  not  been
          accelerated  in  accordance  with  this  paragraph,  that  are not yet
          exercisable  shall become null and void;  provided  however,  that the
          portion,  if any,  of such  options  that  are  exercisable  as of the
          termination date shall continue to be exercisable following the change
          in  status  for the  three  year  period  that you are  employed  as a
          consultant by the Company.  After the third  anniversary  date of this
          Agreement,  the  provisions  set out in (a) and (b) of this  paragraph
          shall no longer  apply.  "Good Reason" shall mean any of the following
          occurring without your prior written consent:

          (1)  A reduction  in your Base Salary or annual bonus  opportunity  or
               profit share below the amounts stated in this Agreement,

          (2)  Removal  or  reassignment  from the  position  of Vice  President
               Corporate  Development  or  the  material  diminishment  of  your
               responsibility or authority;

          (3)  A  requirement  that you be based  anywhere  other than within 25
               miles of Austin,

          (4)  Any material  breach of this Agreement by the Company  which,  if
               capable of remedy,  is not  remedied  for a period of thirty (30)
               days following written notice by you to the Company, specifically
               identifying the nature of the breach.

7.   Employment  Contingent.  This  Agreement,  and  your  employment  with  the
     Company, are contingent upon the following:

     (A)  Successful  passing of a  pre-employment  drug test.  The cost of this
          test is paid by National Instruments.

     (B)  Signing of our employee  Confidentiality  Agreement prior to beginning
          employment  with  National  Instruments.  A copy has been provided for
          your review.

     (C)  Providing proof of eligibility to work in the United States.  You have
          been provided  with a copy of the  Employment  Eligibility  Form which
          list documents which will meet this requirement.  These documents must
          be provided on your first day of employment.

8.   Miscellaneous.

     (A)  Attorneys  Fees. If any action at law, in equity or by  arbitration is
          taken  to  enforce  or  interpret  the  terms of this  Agreement,  the
          prevailing  party  shall be entitled to  reasonable  attorneys'  fees,
          costs and necessary  disbursements  in addition to any other relief to
          which such  party may be  entitled,  including  fees and  expenses  on
          appeal.

     (B)  Construction.  Wherever  possible,  each  provision of this  Agreement
          shall be interpreted in such manner as to be effective and valid under
          applicable  law,  but if any  provision  of this  Agreement  shall  be
          prohibited by or invalid under applicable law, such provision shall be
          ineffective  only to the  extent  of such  prohibition  or  invalidity
          without  invalidating the remainder of such provision or the remaining
          provisions of this Agreement.

     (C)  Waivers.  No failure on the part of either party to  exercise,  and no
          delay in exercising,  any right or remedy hereunder shall operate as a
          waiver thereof;  nor shall any single or partial exercise of any right
          or remedy hereunder  preclude any other or further exercise thereof or
          the  exercise  of any other right or remedy  granted  hereby or by any
          related document or by law.

     (D)  Successors and Assigns. This Agreement shall be binding upon and inure
          to the benefit of the  Company and its  successors  and  assigns,  and
          shall be binding upon Ravel, his administrators,  executors, legatees,
          and heirs. In that this Agreement is a personal services contract,  it
          shall not be assigned by Ravel.

     (E)  Modification.  This  Agreement may not be and shall not be modified or
          amended except by written instrument signed by the parties hereto.

     (F)  Entire Agreement.  This Agreement constitutes the entire agreement and
          understanding  between  the  parties  hereto in  reference  to all the
          matters herein agreed upon. This Agreement replaces and supersedes all
          prior  agreements  whether  written or oral or  understandings  of the
          parties hereto with respect to the subject matter hereof.

     (G)  Choice of Law.  This  Agreement  shall be governed by and construed in
          accordance  with the laws of the  State of  Texas,  and  venue for any
          lawsuit  concerning  breach and/or  enforcement  of this  Agreement or
          relating  in any way or  manner to this  Agreement  will lie in Travis
          County, Texas.

     (H)  Arbitration.  I agree that, to the fullest  extent allowed by law, any
          controversy  or claim  arising out of or  relating  to this  Agreement
          shall be finally  settled by binding  arbitration  administered by the
          American  Arbitration  Association  under its  National  Rules for the
          Resolution of Employment  Disputes.  The arbitration will be conducted
          in the city in which I am or was last employed. I understand that I am
          waiving  my  rights to trial by jury,  in  exchange  for  arbitration.
          Judgment upon any award rendered in an  arbitration  proceeding may be
          entered in any court having jurisdiction  thereof.  Any controversy or
          claim  subject to  arbitration  shall be deemed  waived,  and shall be
          forever  barred,  if arbitration is not initiated  within one (1) year
          after the date the  controversy or claim first arose,  or if statutory
          rights  are  involved,  within  the  time  limit  established  by  the
          applicable  statute  of  limitations.  In  any  arbitration  commenced
          pursuant to this  paragraph,  depositions  may be taken and  discovery
          obtained as provided in the Federal Rules of Civil Procedure,  subject
          to limitation by the arbitrator to a reasonable  amount.  Any award by
          the  arbitrator(s)  shall be accompanied by a statement of the factual
          and legal bases for the award.



     To indicate  your  acceptance  of these terms,  please sign and return this
Agreement and retain the attached  copy for your  records.  If you choose to fax
your signed National  Instruments Job Offer to us  (512-683-8775),  please bring
the  signed  original  with you on your first day of work so it may be placed in
your employee file.


NATIONAL INSTRUMENTS CORPORATION:         EMPLOYEE:
By: /s/ James J. Truchard                 Name (Printed): Mihir Ravel
Title: President                          Signature: /s/ Mihir Ravel
Date: April 18, 2000                      Date: April 18, 2000




                                                                    Attachment A


Reloctation Summary


It is agreed  that  National  Instruments  will cover the  following  relocation
expenses related to the movement of Mihir Ravel, (Relocatee) and his family from
Portland Oregon to Austin Texas. Listed below is a summary of expenses:

Movement of Household  Goods.  The Human Resource office will arrange for and NI
will pay directly for, the movement of household goods from the former residence
or  temporary  storage  to the new place of  residence.  Movement  included  the
Relocatee's and household members'  household effects,  furnishings and personal
effects,  subject to a maximum of 15,000 pounds.  Movement does not include such
things as pick up from two locations, split or partial shipment or delivery, and
access into storage before  delivery.  Household goods does not normally include
such items as boats (any size),  campers,  airplanes,  frozen foods,  livestock,
live  plants,  or  hazardous  materials  including  firewood,  lumber  and other
building materials. One vehicle may be shipped when driving one or more vehicles
to the new location.  Cost  incurred for shipment of not included  items will be
charged to the Relocatee.

House/Apartment  Hunting  trip.  The Relocate and spouse may be  reimbursed  for
reasonable expenses incurred during one  house/apartment  hunting trip including
travel, meals, lodging and car rental.  Travel if by air is coach/economy.  Auto
travel is reimbursed on a per mile basis at the prevailing IRS stated allowance.
Lodging and meals are  reimbursed  on an actual basis and original  receipts are
required for expenses.

Temporary  Living.  If the Relocatee and family cannot move immediately into new
quarters,  reimbursement  may  be  made  for  lodging  cost  incurred  at  their
destination for maximum of 60 days. Original receipts are required.

Real Estate Sale of Current Home.  Eligible Relocatees who are homeowners may be
reimbursed for NORMAL,  CUSTOMARY AND REASONABLE home selling and  non-recurring
cost including the following:

     -normal and customary real estate  brokerage  commission to a maximum of 7%
     (Should you sell your home without a real estate broker,  NI will provide a
     bonus of 3% of the sales price).

     -attorney's fees if required or recommended by law.

     -title fees

     -mortgage  prepayment penalties if they cannot be waived, not to exceed six
     (6) months mortgage interest.

     -transfer and/or documentary taxes the seller is required to pay.

     -inspection and recording fees normally charged to seller.

     -other customary fees directly related to the sale, but which have not been
     incurred  by the choice of the  seller,  such as escrow  fees,  title fees,
     termite inspection, and tax service fee.


Real Estate  Purchase of a New Home.  Eligible  Relocatees who own a home at the
time of the transfer may receive  reimbursement for certain actual and customary
purchaser's  settlement  expenses  when a home is purchased at the new locations
with in six  (6)  months  of the  effective  transfer  date.  NI will  reimburse
reasonable and customary closing expenses including:

     -appraisal fees.

     -recording fees.

     -notary fees.

     -documentary stamps (state, city, county).

     -lender's and homeowner's title insurance.

     -document preparation fee.

     -escrow closing fee.


During Move Travel  Reimbursement  may be made for mileage (at the  per-mile IRS
stated  allowance)  for up to two (2)  vehicles,  lodging,  and meals.  Original
receipts are required for lodging and meals.  Mileage is figured as the shortest
highway distance between point of departure and new location,.

Tax Gross-up.  It is agreed that National  Instruments will cover the additional
taxes which are occurred as the result of the relocation.

Termination  -  Should  an  employee  voluntarily  terminate  employment  within
eighteen (18) months from the time he/she has relocated,  he/she must remit on a
prorated basis all cost relating to the move paid by NI.




Attachment B:  Job Description for Mihir Ravel

Title:  Vice President of Corporate Development, National Instruments

Supervisor:  CEO & President, National Instruments

Major Roles:

Technical Vision

|X|  Match broad technology expertise to NI business strategy.

|X|  Define product strategies that match NI's broad-based market strategy

Strategic Goals

|X|  Define new market and business opportunities

|X|  Work  across  the   organization   as  a  coach  to   capitalize  on  these
     opportunities

Organization Development

|X|  Provide  experience,  technical  expertise  and  vision  to help  build and
     position NI to achieve long term growth goals.

|X|  Help build and expand our current organization and processes to enhance the
     development of NI technical and marketing staff

|X|  Stimulate organization with creative ideas and out-of-the-box thinking

External Development

|X|  Identify and lead external partnership and investment opportunities

Supervision

|X|  Hall T. Martin, (Director of Market Development)

|X|  David Potter, (Product and Technology Strategist)

|X|  Potential new staff: technology and strategic market experts