Exhibit 10.16

AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO
REVOLVING LINE OF CREDIT
NOTE

$4,000,000.00                     Date:    December 31, 1996
Chicago, Illinois                  Due:    April 30, 1998

	FOR VALUE RECEIVED, the undersigned, (jointly and severally if more
than one) ("Borrower"), promises to pay to the order of American National Bank
and Trust Company of Chicago ("Bank"), at its principal place of business in
Chicago, Illinois or such other place as Bank may designate from time to time
hereafter, the principal sum of Four Million and No/100 Dollars ($4,000,000.00)
or such lesser principal sum as may be owed by Borrower to Bank hereunder,
such payment to occur on April 30, 1998.  Borrower's obligations under this
Note shall be defined and referred to herein as "Borrower's Liabilities."

	This Note restates and replaces a Revolving Line of Credit Note in the
principal amount of $4,000,000.00, dated December 27, 1995 executed by
Borrower in favor of Bank (the "Prior Note") and is not a repayment or
novation of the Prior Note.

	Borrower may prepay all or part of the principal, together with
accrued interest on the amount so prepaid, without penalty during the term of
the Note.  All prepayments shall be applied upon installments of the most
remote maturity.

	The principal amount of this Note is available to the Borrower on a
revolving basis. The undersigned may borrow, repay and reborrow any amount,
subject to the limitations contained in the Loan Agreement dated March 28,
1995, as amended from time to time, executed by and between Corcom, Inc. and
Bank (the "Loan Agreement"), provided that the total outstanding principal
balance does not exceed the principal amount of this Note and that Borrower
has complied with all the terms of this Note and the Loan Agreement.  The books
and records of the Bank shall be determinative of the unpaid balance of this
Note from time to time outstanding, absent manifest error. 

	Reference is hereby made to the Loan Agreement for a statement of the
terms and conditions under which the loan evidenced hereby has been made, is
to be repaid and for a statement of Bank's remedies upon the occurrence of an
"Event of Default" as defined in the Loan Agreement.  The terms and conditions
of the Loan Agreement are incorporated herein by reference in their entirety. 

	Borrower's Liabilities unpaid from time to time shall bear interest
(computed on the basis of a 360-day year and actual days elapsed) from the date
hereof until paid at a per annum rate at all times equal to the Bank's Base
Rate or equivalent as announced or published publicly from time to time (the
"Base Rate").  Therefore, interest shall be calculated for each day at 1/360th
of the applicable per annum rate.  The Base Rate is not indicative of the
lowest or best rate offered by the Bank to any customer or group of customers.
A change in the Base Rate shall constitute a corresponding change in the
interest rate hereunder effective on and as of the date of such change in the
Base Rate.  The above notwithstanding, Borrower may elect to and cause all or
a portion of the principal outstanding on this Note to bear interest at a daily
rate equal to one and one-half percent (1 1/2) in excess of the London
Interbank Offered Rate ("LIBOR") as announced by Bank from time to time
pursuant to the terms and conditions of that certain London Interbank Offered
Rate Borrowing Agreement between Borrower and Bank of even date herewith.
Interest accruing prior to maturity shall be payable by Borrower to Bank
monthly, or as billed by Bank to Borrower, at Bank's principal place of
business, or at such other place as Bank may designate from time to time
hereafter.  All unpaid interest at maturity shall be paid with the principal
amount of Borrower's Liabilities due hereunder.

	Upon the occurrence of an Event of Default, as hereinafter defined,
interest on the unpaid principal balance shall accrue at a rate equal to the
then existing Base Rate plus three percent (3%) per annum. 

	Borrower agrees that in any action or proceeding instituted to
collect or enforce collection of this Note, the amount recorded on the books
and records of the Bank shall be prima facie evidence of the unpaid principal
balance of this Note; provided that the failure of the Bank to record any
advance hereunder shall not limit or otherwise affect the obligation of the
Company to repay the principal amount owing on this Note together with accrued
interest thereon.

	If any payment becomes due and payable on a Saturday, Sunday or legal
holiday under the laws of the State of Illinois, the due date of such payment
shall be extended to the next business day.  If the date for any payment of
principal is thereby extended or is extended by operation of law or otherwise,
interest thereon shall be payable at the then applicable rate of interest for
such extended time.

	Borrower warrants and represents to Bank that Borrower shall use the
proceeds represented by this Note solely for the proper business purposes, and
consistently with all applicable laws and statutes. 

	All of Bank's rights and remedies under this Note are cumulative and
non-exclusive. The acceptance by Bank of any partial payment made hereunder
after the time when any of Borrower's Liabilities become due and payable will
not establish a custom, or waive any rights of Bank to enforce prompt payment
thereof.  Bank's failure to require strict performance by Borrower of any
provision of this Note shall not waive, affect or diminish any right of Bank
thereafter to demand strict compliance and performance therewith.  Any waiver
of an Event of Default hereunder shall not suspend, waive or affect any other
Event of Default hereunder.  Borrower and every endorser waive presentment,
demand and protest and notice of presentment, protest, default, non-payment,
maturity, release, compromise, settlement, extension or renewal of this Note,
and hereby ratify and confirm whatever Bank may do in this regard.  Borrower
further waives any and all notice or demand to which Bank might to entitled
with respect to this Note by virtue of any applicable statute or law (to the
extent permitted by law).

	Borrower agrees to pay, upon Bank's demand therefore, any and all
reasonable costs, fees and expenses (including attorneys' fees, costs and
expenses) incurred in enforcing any of Bank's rights hereunder, and to the
extent not paid the same shall become part of Borrower's Liabilities hereunder. 

	If any provision of this Note or the application thereof to any party
or circumstance is held invalid or unenforceable, the remainder of this Note
and the application thereof to other parties or circumstances will not be
affected thereby, the provisions of this Note being severable in any such
instance.

	This Note is submitted by Borrower to Bank at Bank's principal place
of business and shall be deemed to have been made there at.  This Note shall
be governed and controlled by the laws of the State of Illinois as to
interpretation, validity, construction, affect, choice of law and in all other
respects.

	No modification, waiver, estoppel, amendment, discharge or change of
this Note or any related instrument shall be valid unless the same is in
writing and signed by the party against which the enforcement of such
modification, waiver, estoppel, amendment, discharge or change is sought.

	TO INDUCE BANK TO ACCEPT THIS NOTE, BORROWER IRREVOCABLY AGREES THAT,
SUBJECT TO BANK'S SOLE AND ABSOLUTE ELECTION, ALL ACTIONS OR PROCEEDINGS IN
ANY WAY, MANNER OR RESPECT, ARISING OUT OF OR FROM OR RELATED TO THIS NOTE
SHALL BE LITIGATED IN COURTS HAVING SITUS WITHIN THE CITY OF CHICAGO, STATE OF
ILLINOIS.  BORROWER HEREBY CONSENTS TO THE JURISDICTION OF ANY LOCAL, STATE OR
FEDERAL COURT LOCATED WITHIN SAID CITY AND STATE AND WAIVES ANY OBJECTION IT
MAY HAVE BASED ON IMPROPER VENUE OR FORUM NON CONVENIENS TO THE CONDUCT OF ANY
PROCEEDING INSTITUTED HEREUNDER.

	BORROWER AND BANK IRREVOCABLY WAIVE ANY RIGHT TO TRIAL BY JURY IN ANY
ACTION OR PROCEEDING (I) TO ENFORCE OR DEFEND ANY RIGHTS UNDER OR IN
CONNECTION WITH THIS NOTE OR ANY AMENDMENT, INSTRUMENT, DOCUMENT OR AGREEMENT
DELIVERED OR WHICH MAY IN THE FUTURE BE DELIVERED IN CONNECTION HEREWITH OR
(II) ARISING FROM ANY DISPUTE OR CONTROVERSY IN CONNECTION WITH OR RELATED TO
THIS NOTE OR ANY SUCH AMENDMENT, INSTRUMENT, DOCUMENT OR AGREEMENT, AND AGREE
THAT ANY SUCH ACTION OR PROCEEDING SHALL BE TRIED BEFORE A COURT AND NOT
BEFORE A JURY.

			BORROWER:

			CORCOM, INC.
			By:  s/s Thomas J. Buns 
			Its:  Vice President

			ATTESTED:
			By:   s/s Walter Roth
			Its:   Secretary


LONDON INTERBANK OFFERED RATE BORROWING AGREEMENT

	THIS LONDON INTERBANK OFFERED RATE ("LIBOR") BORROWING AGREEMENT
(this "Agreement"), dated as of the 31st day of December, 1996 by and between
AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO ("Bank"), a national
banking association with its principal place of business at 33 North LaSalle
Street, Chicago, Illinois  60690, and CORCOM, INC., ("Borrower"), an Illinois
corporation with its principal place of business at 844 East Rockland Road,
Libertyville, Illinois, has reference to the following facts and
circumstances:

	A.	Borrower has requested and Bank has agreed to extend an
interest rate option of 1.50% per annum in excess of the LIBOR; and

	B.	Borrower has executed a Promissory Note dated December 31,
1996, in the amount of $4,000,000.00 in favor of Bank (the "Note") which
reflects the LIBOR option.

	NOW, THEREFORE, in consideration of any loan, advance, extension of
credit and/or other financial accommodation at any time made by Bank to or for
the benefit of Borrower, and of the promises set forth herein, the parties
hereto agree as follows:

1.  DEFINITIONS AND TERMS

	1.1	 The following words, terms and/or phrases shall have the
meanings set forth thereafter and such meanings shall be applicable to the
singular and plural form thereof; whenever the context so requires, the use of
"it" in reference to Borrower shall mean Borrower as identified at the
beginning of this Agreement:

		(a)	"Amortization Date":  the dates specified in the Note
                 when principal payments are due.

		(b)	"Borrowing": any portion of Borrower's liabilities
                 bearing interest at LIBOR.

		(c)	"Business Day": any day on which American National
                Bank and Trust Company of Chicago, 33 N. LaSalle Street,
                Chicago, Illinois 60690,is open for regular business.

		(d)	"Event of Default": the definition ascribed to this
                 term in the Note.

		(e)	"Interest Period": the period commencing on the date
                a LIBOR Loan is made and ending, as the Borrower may select,
                30, 60, 90, 120 or 180 days thereafter.

		(f)	"LIBOR Loans": any principal portion of Borrower's
                liabilities bearing interest at LIBOR.

		(g)	"LIBOR Margin":  150 basis points (1.50%).

		(h)	"Maturity Date":  the date specified in the Note upon
                which the Borrower's liabilities are due and payable in full.

	1.2	Any terms or phrases not specifically defined in this
Agreement shall have the meanings ascribed to them in the Note.

	2.  MANNER OF LIBOR ELECTION

	2.1	Borrower may elect to cause all or a portion of the principal
outstanding on the Notes to bear interest at a daily rate equal to the daily
rate equivalent of 1.50% in excess of LIBOR, subject to the following 
conditions:
		
	(a)	Not more than five (5) nor less than two (2) Business Days
prior to the requested date of any LIBOR Borrowing, Borrower shall deliver to
Bank an irrevocable written or telephonic notice setting forth the requested
date and amount of such Borrowing (which amount shall not be less than
$100,000.00 and, if in excess of $100,000.00, shall be in integral multiples
of $100,000.00) and the requested Interest Period of such Borrowing;

	(b)  	The LIBOR used in computing the interest rate applicable to
such Borrowing shall be the LIBOR as quoted by Bank to Borrower as being in
effect for the date of such Borrowing plus the LIBOR Margin, computed on the
basis of a 360-day year and actual days elapsed, and shall be fixed for the
requested period of such Borrowing;

	(c)  	Such Borrowing may not be prepaid prior to the expiration of
the requested Interest Period of such Borrowing and shall be repaid in full
on the last day of the requested Interest Period of such Borrowing;

	(d)  	With respect to any Borrowing of LIBOR Loans, Borrower may
not select an Interest Period that extends beyond the Maturity Date of the
Note; and

	(e)  	With respect to any Borrowing of LIBOR Loans under the Note,
Borrower may not select an Interest Period that extends beyond any
Amortization Date unless, after giving effect to such requested Borrowing,
the aggregate unpaid principal amount of such Loans having Maturity Dates
after such Amortization Date does not exceed the aggregate principal amount of
the Note scheduled to be outstanding after such Amortization Date.

	2.2	In the event Borrower fails to give notice pursuant to Section
2.1(a) above of the borrowing of the principal amount of any maturing LIBOR
Borrowing and has not notified the Bank by 10:00 a.m. (Chicago time) on the
day such Borrowing matures that it intends to renew such Borrowing, then
Borrower shall be deemed to have requested a Borrowing of Base or Prime Rate
Loans (as defined in the Note) on such day in the amount of the maturing
Borrowing.

	3.  GENERAL PROVISIONS

	3.1	Funding Indemnity.  In the event Bank shall incur any loss,
cost or expense (including, without limitation, any loss of profit, and any
loss, cost or expense incurred by reason of the liquidation or re-employment
of deposits or other funds acquired by such Bank to fund or maintain any
LIBOR Loan or the relending or reinvesting of such deposits or amounts paid
or prepaid to such Bank) as a result of:

	(a)  	any payment or prepayment of a LIBOR Loan on a date other than
the last day of its Interest Period,

	(b)  	any failure by Borrower to borrow a LIBOR Loan on the date
specified in a notice given pursuant to Section 2.1 hereof,

	(c)  	any failure by Borrower to make any payment of principal on
any LIBOR Loan when due (whether by acceleration or otherwise), or

	(d)  	any acceleration of the maturity of a LIBOR Loan as a result
of the occurrence of any Event of Default, 

then, upon the demand of Bank, Borrower shall pay to Bank such amount as will
reimburse Bank for such loss, cost or expense.  If Bank makes such a claim
for compensation, it shall provide to Borrower a certificate executed by an
officer of Bank setting forth the amount of such loss, cost or expense in
reasonable detail (including an explanation of the basis for the computation
of such loss, cost or expense) and the amounts shown on such certificate if
reasonably calculated shall be conclusive.

	3.2	Availability of LIBOR Loans.  If Bank determines that
maintenance of its Loans would violate any applicable law, rule, regulation,
or directive, whether or not having the force of law, or if Bank determines
that deposits of a type and maturity appropriate to match fund LIBOR Loans
are not available to it then Bank shall forthwith give notice thereof to
Borrower, whereupon, until Bank notifies Borrower that the circumstances
giving rise to such suspension no longer exist, the obligations of the
Bank to make LIBOR Loans shall be suspended.

	IN WITNESS WHEREOF, this Agreement has been duly executed as of the
day and year specified at the beginning hereof.

CORCOM, INC.

By:_s/s Thomas J. Buns
Its:   Vice President

ATTEST:
By: s/s Walter Roth
           Secretary

	Accepted this  31st day of December, 1996, at Bank's principal place
of business in the City of Chicago, State of Illinois.

AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO

By:   s/s  Jack C. Gonder
Its:    Commercial Banking Officer