SC 14D1/A

                      SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                Amendment No. 2
                                       to
                                 SCHEDULE 14D-1
                             Tender Offer Statement
      Pursuant to Section 14(d)(1) of the Securities Exchange Act of 1934
                                      and
                                Amendment No. 2
                                       to
                                  SCHEDULE 13D
                   under the Securities Exchange Act of 1934

                          Applied Digital Access, Inc.
                          ----------------------------
                           (Name of Subject Company)

                        Dynatech Acquisition Corporation
                            an indirect wholly-owned
                                 subsidiary of
                              Dynatech Corporation
                                   (Bidders)

                    Common Stock, Par Value $0.001 per Share
                    ----------------------------------------
                         (Title of Class of Securities)

                                    03818103
                                    --------
                     (CUSIP Number of Class of Securities)

                        DYNATECH ACQUISITION CORPORATION
                               MARK V.B. TREMALLO
                                   SECRETARY
                          3 NEW ENGLAND EXECUTIVE PARK
                           BURLINGTON, MASSACHUSETTS
                                 (781) 272-6100
  (Name, Address and Telephone Number of Person Authorized to Receive Notices
                    and Communications On Behalf of Bidders)

                                    COPY TO:
                           FRANCI J. BLASSBERG, ESQ.
                              DEBEVOISE & PLIMPTON
                                875 THIRD AVENUE
                               NEW YORK, NY 10022
                                 (212) 909-6000


   This Amendment No. 2 amends and supplements the information set forth in the
Tender Offer Statement on Schedule 14D-1 (the "Schedule 14D-1") filed by
Dynatech Acquisition Corporation (the "Purchaser") and Dynatech Corporation
("Parent") on September 14, 1999, as amended by Amendment No. 1, filed by the
Purchaser and Parent on September 28, 1999, with respect to shares of common
stock, par value $0.001 per share, of Applied Digital Access, Inc. (the
"Company").  Unless otherwise indicated, the capitalized terms used herein shall
have the meanings specified in the Schedule 14D-1, including the Offer to
Purchase filed as Exhibit (a)(1) thereto.

ITEM 10.  ADDITIONAL INFORMATION

   The response to Item 10(e) is hereby amended and supplemented by the addition
of the following two paragraphs after the final sentence of Item 10(e):

   On October 1, 1999, the Purchaser and Parent were served with a class action
lawsuit filed by an alleged shareholder of the Company.  The lawsuit was filed
in the Superior Court of the State of California, County of San Diego, and
alleges that the Company and certain members of its board of directors breached
fiduciary duties to the Company's shareholders in connection with the Offer and
that the Purchaser and Parent aided and abetted in such breach.  Three similar
lawsuits also have been filed in that court on September 15, 1999, September 21,
1999, September 23, 1999, each alleging that the Company and certain members of
its board of directors breached fiduciary duties to the Company's shareholders
in connection with the Offer.  A fifth lawsuit has been filed in the Court of
Chancery in the State of Delaware in and for New Castle County also alleging
that the Company and certain members of its board of directors breached
fiduciary duties to the Company's shareholders in connection with the Offer.

   On September 20, 1999, the Company issued a press release, a copy of which is
attached hereto as Exhibit 99(a)(9) and is incorporated herein by reference.

   On October 6, 1999, Parent issued a press release, a copy of which is
attached hereto as Exhibit 99(a)(10) and is incorporated herein by reference.

   The response to Item 10(f) is hereby amended and supplemented by the addition
of the following two paragraphs after the final sentence of Item 10(f):

   The Purchaser and Parent extend the period of time during which the Offer is
open. The Offer and withdrawal rights will expire at 12:00 midnight, New York
City Time, on Monday, November 1, 1999, unless the Offer is extended.

   On October 6, 1999, Parent issued a press release, a copy of which is
attached hereto as Exhibit 99(a)(10) and is incorporated herein by reference.

ITEM 11.  MATERIAL TO BE FILED AS EXHIBITS

   Item 11 of the Schedule 14D-1 is hereby amended and supplemented by adding
the following text thereafter:

   (a)(9) Press release issued by the Company on September 20, 1999.

   (a)(10) Press release issued by Parent on October 6, 1999.


                                   SIGNATURE

     After due 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.

Dated: October 6, 1999

                       DYNATECH ACQUISITION CORPORATION


                       By:  /s/ Mark V.B. Tremallo
                          -----------------------------------
                          Name: Mark V.B. Tremallo
                          Title: Vice President and Secretary



                       DYNATECH CORPORATION


                       By:  /s/ Mark V.B. Tremallo
                          -----------------------------------
                          Name: Mark V.B. Tremallo
                          Title: Corporate Vice President - General Counsel
                                   and Secretary


                                 EXHIBIT INDEX




  EXHIBIT                                                                                PAGE
    NO.                                 DESCRIPTION                                       NO.
- ------------     ---------------------------------------------------------------------   ----
                                                                                   
99(a)(1)*        Offer to Purchase dated September 14, 1999 ..........................

99(a)(2)*        Letter of Transmittal ...............................................

99(a)(3)*        Notice of Guaranteed Delivery .......................................

99(a)(4)*        Letter to Brokers, Dealers, Commercial Banks, Trust Companies
                 and Nominees ........................................................

99(a)(5)*        Letter to clients for use by Brokers, Dealers, Commercial Banks,
                 Trust Companies and Nominees ........................................

99(a)(6)*        Guidelines for Certification of Taxpayer Identification Number on
                 Substitute Form W-9 .................................................

99(a)(7)*        Summary Advertisement as published on September 14, 1999 ............

99(a)(8)*        Press Release issued by Parent on September 8, 1999 .................

99(a)(9)         Press Release issued by the Company on September 20, 1999............

99(a)(10)        Press Release issued by Parent on October 6, 1999 ...................

99(b)(1)*        Credit Agreement, dated May 21, 1998, by and among Parent, TTC
                 Merger Co., LLC, the lenders named therein, Morgan Guaranty and
                 Trust Company of New York, as administrative agent, Credit Suisse
                 First Boston, as syndication agent, and The Chase Manhattan Bank,
                 as documentation agent. .............................................

99(c)(1)*        Short Form Confidentiality Agreement, effective April 13, 1999,
                 between Parent and the Company. .....................................

99(c)(2)*        Letter, dated August 13, from Parent to the Company. ................

99(c)(3)*        Agreement and Plan of Merger, dated as of September 7, 1999,
                 among Parent, the Purchaser and the Company .........................


____________________
*As previously filed.

EX-99.(A)(9)

                                                                Exhibit 99(a)(9)

NEWS RELEASE

Editor's Contact:

Don Strohmeyer/Eric Houser
Applied Digital Access
Phone: 858-623-2200
Fax: 858-623-2208
don.strohmeyer@ada.com
eric.houser@ada.com

Gwen Carlson/Frank Bantle
The Townsend Agency
Phone: 858-457-4888, ext. 116
Fax: 858-453-7010
gwen@townsendagency.com
frank@townsendagency.com


                  MILBERG WEISS BERSHAD HYNES & LERACH, L.L.P.

             FILES CLASS ACTION SUIT AGAINST APPLIED DIGITAL ACCESS

SAN DIEGO--September 20, 1999--Applied Digital Access, Inc. (ADA) (NASDAQ:
ADAX), a leading provider of innovative service fulfillment and service
assurance solutions to the telecommunications industry, today announced on
September 18, 1999, following the announcement of the tender offer by Dynatech
Corporation for the outstanding shares of ADA stock, ADA was served with a class
action lawsuit filed by a single alleged shareholder of the company.  The
lawsuit was filed in California state court and alleges that ADA and certain
members of its board of directors breached fiduciary duties to the company's
shareholders in connection with the tender offer.  Lawsuits of this type are
frequently filed immediately after the announcement of a major corporate
transaction, such as a tender offer.  In the company's opinion, the lawsuit has
no merit and it intends to vigorously defend against it.

Applied Digital Access is a leading provider of innovative telecommunications
service fulfillment and service assurance solutions that are backed by
unparalleled customer


support. These solutions enable a wide range of telecommunications service
providers to improve network operations performance, proactively manage the
quality of service, increase productivity, and lower operating expenses. The
company is headquartered in San Diego, California along with the unit that
specializes in the design, development and delivery of its service assurance
test and monitoring systems. The Carrier Operations Support Systems (OSS)
software and service unit is located Vancouver, British Columbia and Terre
Haute, Indiana. Press releases and other information about Applied Digital
Access, its products, and services are available on the Web at www.ada.com.

"Safe Harbor" statement under the Private Securities Litigation Reform Act of
1995: Except for historical information contained in this release, the preceding
may contain forward-looking statements that involve potential risks and
uncertainties as detailed in ADA's Annual Report on Form 10-K for the year
ended 12/31/98 and the most recent Form 10-Qs, which include: customer mergers,
fluctuations in quarterly operating results; history of losses, competition,
concentration of major customers; telephone company qualification requirements,
dependence on two product lines, management of changing business, rapid
technological change and dependence on new products, dependence on suppliers and
subcontractors, high inventory levels and need to make advance purchase
commitments, year 2000 compliance, product recall and defects, government
regulation, potential competition from RBOCs, proprietary technology, dependence
on key personnel and volatility of stock price. The Company's actual results
could differ materially from those discussed in this release. Readers are
cautioned not to place undue reliance on these forward-looking statements, which
speak only as of the date hereof.  The Company undertakes no obligation to
revise or update these forward-looking statements to reflect events or
circumstances after the date of this release.

EX-99.(A)(10)

                                                               EXHIBIT 99(A)(10)


                   DYNATECH CORPORATION EXTENDS TENDER OFFER
                           FOR APPLIED DIGITAL ACCESS

October 6, 1999

Burlington, MA -- October 6, 1999 -- Dynatech Corporation (OTC-BB:DYNA) today
announced that on October 1, 1999, following the announcement of the tender
offer by Dynatech Corporation for the outstanding shares of San Diego-based
Applied Digital Access, Inc. (ADA) (NASDAQ:ADAX), Dynatech was served with a
class action lawsuit filed by an alleged shareholder of ADA. The lawsuit was
filed in California state court and alleges that Dynatech "aided and abetted"
ADA and certain members of its board of directors in breaching their fiduciary
duties to ADA's shareholders in connection with the tender offer. In Dynatech's
opinion, this lawsuit and four similar lawsuits filed against ADA have no merit
and Dynatech intends to vigorously defend against them. Dynatech is extending
the period of time during which the offer is open until 12:00 midnight, New York
City Time, on Friday, October 29, 1999.

Dynatech Corporation (OTC-BB:DYNA) is a global communications equipment company
focused on network technology solutions.  Its products address communications
test, industrial computing and communications, and visual communications
applications. Headquartered in Burlington, Massachusetts, Dynatech sells its
products worldwide through subsidiaries located throughout the Americas, Europe
and Asia.

NOTE: This press release may contain forward-looking statements within the
meaning of Section 27A of the Securities Act of 1933, as amended, and Section
21E of the Securities Exchange Act of 1934, as amended, which reflect the
Company's current judgment on certain issues.  Because such statements apply to
future events, they are subject to risks and uncertainties that could cause the
actual results to differ materially.  Important factors that could cause actual
results to differ materially are described in the company's reports on Form 10-K
and 10-Q on file with the Securities and Exchange Commission.