EXHIBIT 10d
                               
                               
                               
        AMENDED AND RESTATED CREDIT FACILITY AGREEMENT
                      AMENDMENT NUMBER 2
                               
                               
     THIS AMENDMENT is made as of the 13th day of February,
1997, by and among DETECTION SYSTEMS, INC., a corporation
formed under the laws of the State of New York with offices at
130 Perinton Parkway, Fairport, New York 14450 ("Detection"),
RADIONICS, INC., a corporation formed under the laws of the
State of California with offices at 1800 Abbott Street,
Salinas, California 93901 ("Radionics"), and FLEET BANK, a bank
and trust company formed under the laws of the State of New
York with offices at One East Avenue, Rochester, New York 14638
("Bank").

     WHEREAS, the parties entered into an Amended and Restated
Credit Facility Agreement dated as of May 25, 1996, as amended
by Amended and Restated Credit Facility Agreement Amendment
Number 1 dated as of January 27, 1997 (the "Credit Agreement"),
and

     WHEREAS, the parties desire to further amend the Credit
Agreement,


     NOW THEREFORE, the parties hereby agree as follows:

The following definitions contained in Section 1.1 of the
Credit Agreement are hereby amended to read in their entirety
as follows:

     "Applicable Base Rate Margin" shall mean the following
amounts for the following respective ratios of Funded Debt to
EBITDA, calculated for the Borrower and Eligible Subsidiaries
on a consolidated basis and without duplication in accordance
with GAAP:

Ratio                                   Margin (Basis Points)
5 to 1 or greater                       75.0
4 to 1 or greater and less than 5 to 1  50.0
3 to 1 or greater and less than 4 to 1  37.5
2 to 1 or greater and less than 3 to 1  12.5
Less than 2 to 1                        0.0

     The Applicable Base Rate Margin shall be adjusted at the
beginning of each three month period commencing either March 1,
July 1, September 1, and December 1 respectively, and shall be
established for that period based upon the average rolling
ratios shown by the Borrower's financial statements for the
four fiscal quarters ending on the most recent December 31,
March 31, June 30, or September 30 respectively.

     "Applicable LIBOR Margin" shall mean the following amounts
for the following respective ratios of Funded Debt to EBITDA,
calculated for the Borrower and Eligible Subsidiaries on a
consolidated basis and without duplication in accordance with
GAAP:

Ratio                              Margin (Basis Points)
5 to 1 or greater                       200.0
4 to 1 or greater and less than 5 to 1  175.0
3 to 1 or greater and less than 4 to 1  162.5
2 to 1 or greater and less than 3 to 1  125.0
Less than 2 to 1                        112.5

     The Applicable LIBOR Margin shall be adjusted at the
beginning of each three month period commencing either March 1,
July 1, September 1, and December 1 respectively, and shall be
established for that period based upon the average rolling
ratios shown by the Borrower's financial statements for the
four fiscal quarters ending on the most recent December 31,
March 31, June 30, or September 30 respectively.

     2.  Section 2.1 of the Credit Agreement is hereby amended
to read in its entirety as follows:

     2.1  Revolving Line.   Subject to the terms and conditions
of this Agreement, the Bank hereby establishes for the benefit
of the Borrower a revolving line of credit in the maximum
principal amount of Eleven Million Five Hundred Thousand
Dollars ($11,500,000) outstanding at any one time.  The
proceeds of the Revolving Line shall be used for Borrower's
working capital purposes.  Subject to the terms of this
Agreement, the Borrower (or either of them) may borrow, repay,
and reborrow under the Revolving Line so long as the aggregate
principal amount outstanding at any time to the Borrower does
not exceed $11,500,000.  Each borrowing request must be of at
least $250,000.

3.  The second paragraph of Section 2.4 of the Credit Agreement
is hereby deleted.

4.  Section 2.7 of the Credit Agreement is hereby amended to
read in its entirety as follows:

2.7  Unused Fee.   The Borrower shall pay to the Bank an unused
fee computed at the following applicable Fee Rate for the
respective applicable ratio of Funded Debt to EBITDA,
calculated for the Borrower and Eligible Subsidiaries on a
consolidated basis and without duplication in accordance with
GAAP:

     Ratio                              Fee Rate (Basis Points)
     5 to 1 or greater                       25.00
     4 to 1 or greater and less than 5 to 1  18.75
     3 to 1 or greater and less than 4 to 1  18.75
     2 to 1 or greater and less than 3 to 1  18.75
     Less than 2 to 1                        12.50


     Each Fee Rate shall be adjusted at the beginning of each
three month period commencing either March 1, July 1, September
1, and December 1 respectively, and shall be established for
that period based upon the average rolling ratios shown by the
Borrower's financial statements for the four fiscal quarters
ending on the most recent December 31, March 31, June 30, or
September 30 respectively.

     The unused fee shall be computed as follows: $11,500,000,
minus the average daily outstanding principal balance of the
Revolving Line, times the Fee Rate per annum. At the end of
each fiscal quarter, the Bank will bill the Borrower for the
unused fee.

     5.   On the date of execution of this Amendment, the
Borrower shall pay to the Bank an amendment fee of $20,000 in
connection with the amendments to the Credit Agreement made
hereby.

     6.   Exhibit A to the Credit Agreement is hereby amended
to read in its entirety in the form of Exhibit A to this
Amendment.

     7.   All other terms of the Credit Agreement shall remain
unchanged and in full force and effect.

     8.   Borrower represents and warrants that (a) each of the
representations and warranties set forth in the Credit
Agreement is true and correct as of the date hereof (and with
respect to the representations and warranties set forth in
Section 6.5 of the Credit Agreement, the financial statements
referred to therein shall mean the financial statements of the
Borrowers for the most recent quarterly period ended); and (b)
no Event of Default or event that, with the giving of notice or
the passage of time or both would constitute an Event of
Default, has occurred and is continuing.


     IN WITNESS WHEREOF, the parties have executed this
Amendment on the date first above written.


                              FLEET BANK


                              By:  /s/ Jeffrey Holmes

                              Title: Vice President



                              DETECTION SYSTEMS, INC.


                              By:  /s/ Frank J. Ryan

                              Title: Vice President



                              RADIONICS, INC.


                              By:  /s/ Frank J. Ryan

                              Title: CFO, Secretary, Treasurer



EXHIBIT A

AMENDED AND RESTATED REVOLVING LINE NOTE

$11,500,000                                       February 13,
1997

          Unless otherwise expressly provided herein, all
capitalized terms in this Amended and Restated Revolving Line
Note ("Revolving Line Note") shall have the meanings given to
them in the Amended and Restated Credit Facility Agreement
dated as of May 31, 1996, between the undersigned ("Borrower")
and Fleet Bank ("Bank"), as the same has been and may be
amended, extended, replaced, or modified from time to time (the
"Credit Agreement").

     This Revolving Line Note amends, replaces, and restates in
its entirety the Revolving Line Note dated as of May 31, 1996
given by the Borrower in favor of the Bank.


     FOR VALUE RECEIVED, the Borrower, jointly and severally,
hereby promises to pay to the order of the Bank, at any of its
banking offices, or at such other places as Bank may specify in
writing to Borrower, the principal sum of Eleven Million Five
Hundred Thousand Dollars ($11,500,000), or if less, the
aggregate unpaid principal amount of all advances made by Bank
to Borrower.  Bank shall maintain a record of amounts of
principal and interest payable by Borrower from time to time,
and the records of Bank maintained in the ordinary course of
business shall be prima facie evidence of the existence and
amounts of the Borrower's obligations recorded therein.  In
addition, Bank may mail or deliver periodic statements to
Borrower indicating the date and amount of each advance
hereunder (but any failure to do so shall not relieve Borrower
of the obligation to repay any advance).  Unless Borrower
questions the accuracy of an entry on any periodic statement
within fifteen business days after such mailing or delivery by
Bank, Borrower shall be deemed to have accepted and be
obligated by the terms of each such periodic statement as
accurately representing the advances hereunder.  In the event
of transfer of this Revolving Line Note, or if the Bank shall
otherwise deem it appropriate, Borrower hereby authorizes Bank
to endorse on this Revolving Line Note the amount of advances
and payments to reflect the principal balance outstanding from
time to time.  Bank is hereby authorized to honor borrowing and
other requests received from purported representatives of
Borrower orally, by telecopy, in writing, or otherwise.  Oral
requests shall be conclusively presumed to have been made by an
authorized person and Bank's crediting of Borrower's account
with the amount requested shall conclusively establish
Borrower's obligation to repay the amount advanced.

     Interest.  All outstanding amounts under this Revolving
Line Note shall bear interest until paid in full at the Base
Rate plus the Applicable Base Rate Margin.  Changes in the rate
of interest applicable to this Revolving Line Note shall become
effective automatically and without notice at the time of
changes in the Base Rate.

     The Borrower, however, at least three business days prior
to each Rate Change Date may notify the Bank of its election to
have a portion of the outstanding principal amount under this
Revolving Line Note (which must be at least $1,000,000 and must
be an increment of $100,000) bear interest for a one-month,
three-month, or six month period commencing on such Rate Change
Date at the LIBOR Rate plus the Applicable LIBOR Margin.

     Interest shall be calculated based on actual days elapsed
divided by a year of 360 days.  Interest shall continue to
accrue after maturity, including after acceleration and
judgment, at the rate required by this Revolving Line Note
until this Revolving Line Note is paid in full.  The rate of
interest on this Revolving Line Note may be increased under the
circumstances provided in the Credit Agreement. The right of
Bank to receive such increased rate of interest shall not
constitute a waiver of any other right or remedy of Bank.

     Payments.  Payments of all accrued interest under this
Revolving Line Note shall be due and payable on the first day
of each month.

     All remaining outstanding principal and accrued interest
shall be due and payable in full on the Revolving Line
Termination Date.

     All payments shall be in lawful money of the United States
in immediately available funds.  Unless canceled in writing by
Borrower, Borrower authorizes Bank to debit its accounts at
Bank to make payments due hereunder, but such authority shall
not relieve Borrower of the obligation to assure that payments
are made when due.

     Late Charge.  This Revolving Line Note is subject to the
late charges provided in the Credit Agreement.

     Maximum Rate.  At no time shall Borrower be obligated or
required to pay interest under this Revolving Line Note at a
rate which exceeds the maximum rate permitted by applicable law
or regulation.  If by the terms of this Revolving Line Note
Borrower is at any time required or obligated to pay interest
at a rate in excess of such maximum rate, the rate of interest
under this Revolving Line Note shall be deemed to be
immediately reduced to such maximum rate and each payment of
interest that exceeds such maximum rate shall be deemed a
voluntary prepayment of principal.

     Prepayment.  This Revolving Line Note is freely prepayable
in whole or in part at any time, subject to payment of Break
Costs, if any, as provided in the Credit Agreement.

     Holidays.  If this Revolving Line Note or any payment
hereunder becomes due on a day not a Business Day, the due date
of this Revolving Line Note or payment shall be extended to the
next succeeding Business Day, but any interest or fees shall be
calculated based upon the actual time of payment.

     Events of Default.  At Bank's option, this Revolving Line
Note shall become immediately due and payable in full, without
further presentment, protest, notice, or demand, upon the
happening of any Event of Default.

     Modification of Terms.  The terms of this Revolving Line
Note cannot be changed, nor may this Revolving Line Note be
discharged in whole or in part, except by a writing executed by
Bank.  In the event that Bank demands or accepts partial
payments of this Revolving Line Note, such demand or acceptance
shall not be deemed to constitute a waiver of the right to
demand the entire unpaid balance of this Revolving Line Note at
any time in accordance with the terms hereof.  Any delay or
omission by Bank in exercising any rights hereunder shall not
operate as a waiver of such rights.

     Collection Costs.  Borrower on demand shall pay all
expenses of Bank, including without limitation reasonable
attorneys' fees, in connection with enforcement and collection
of this Revolving Line Note.

     Miscellaneous.  To the fullest extent permissible by law,
Borrower waives presentment, demand for payment, protest,
notice of nonpayment, and all other demands or notices
otherwise required by law in connection with the delivery,
acceptance, performance, default, or enforcement of this
Revolving Line Note.  Borrower consents to extensions,
postponements, indulgences, amendments to notes and agreements,
substitutions or releases of collateral, and substitutions or
releases of other parties primarily or secondarily liable
herefor, and agrees that none of the same shall affect
Borrower's obligations under this Revolving Line Note which
shall be unconditional.

     Laws.  Borrower agrees that this Revolving Line Note shall
be governed by the laws of the State of New York.


                              DETECTION SYSTEMS, INC.

                              By: /s/ Frank J. Ryan

                              Title: Vice President


                              RADIONICS, INC.


                              By: /s/ Frank J. Ryan

                              Title: CFO, Secretary, Treasurer