<PAGE>

                                                                    EXHIBIT 10.6


                          CREDIT AND SECURITY AGREEMENT

                            Dated as of June 17, 1999

                  VICOM, INCORPORATED, a Minnesota corporation (the "Borrower"),
and WELLS FARGO BUSINESS CREDIT, INC., a Minnesota corporation (the "Lender"),
hereby agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

                  Section I.1  DEFINITIONS.  For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

                  "Accounts" means the aggregate unpaid obligations of customers
         and other account debtors to the Borrower arising out of the sale or
         lease of goods or rendition of services by the Borrower on an open
         account or deferred payment basis, whether now existing or hereafter
         arising.

                  "Advance" has the meaning given in Section 2.1

                  "Book Net Income" (or "Book Net Loss," as the case may be)
         means the year-to-date net income or loss of the Borrower, determined
         in accordance with GAAP except excluding extraordinary items.

                  "Borrowing Base" means, at any time and subject to change from
         time to time in the Lender's sole discretion, the lesser of:

                  (a)      the Maximum Line; or

                  (b)      the sum of:

                           (i)      the lesser of (A) 80% of Eligible Accounts
                                    or (B) $2,000,000, plus

                           (ii)     the lesser of (A) 30% of Eligible Inventory
                                    or (B) $600,000.

                  "Collateral" has the meaning given in Section 3.1.

                  "Default Rate" means an annual rate equal to 3% over the
         Floating Rate, which rate shall change when and as the Floating Rate
         changes.

                  "Eligible Accounts" means all unpaid Accounts, net of any
         credits, except the following shall not in any event be deemed Eligible
         Accounts:

                           (1) That portion of Accounts over 90 days past
                  invoice date;

                           (2) That portion of Accounts that are disputed or
                  subject to a claim of offset or a contra account;

                           (3) That portion of Accounts not yet earned by the
                  final delivery of goods or rendition of services, as
                  applicable, by the Borrower to the customer;

<PAGE>

                           (4)  Accounts owed by any unit of government, whether
                  foreign or domestic (provided, however, that there shall be
                  included in Eligible Accounts that portion of Accounts owed by
                  such units of government for which the Borrower has provided
                  evidence satisfactory to the Lender that (A) the Lender has a
                  first priority perfected security interest and (B) such
                  Accounts may be enforced by the Lender directly against such
                  unit of government under all applicable laws);

                           (5)  Accounts owed by an account debtor located
                  outside the United States which are not backed by a bank
                  letter of credit assigned to the Lender, in the possession of
                  the Lender and acceptable to the Lender in all respects, in
                  its sole discretion;

                           (6)  Accounts owed by an account debtor that is the
                  subject of bankruptcy proceedings, has gone out of business or
                  has poor credit;

                           (7)  Accounts owed by a shareholder, subsidiary,
                  affiliate, officer or employee of the Borrower;

                           (8)  Accounts not subject to a duly perfected
                  security interest in favor of the Lender or which are subject
                  to any lien, security interest or claim in favor of any Person
                  other than the Lender;

                           (9)  That portion of Accounts that have been
                  restructured, extended, amended or modified;

                           (10) That portion of Accounts that constitutes
                  finance charges, service charges or sales or excise taxes;

                           (11) Accounts owed by an account debtor, regardless
                  of whether otherwise eligible, if 10% or more of the total
                  amount due under Accounts from such debtor is ineligible under
                  clauses (1), (2) or (9) above; and

                           (12) Accounts, or portions thereof, otherwise deemed
                  ineligible by the Lender in its sole discretion.

                  "Eligible Inventory" means all Inventory of the Borrower, at
         the lower of cost or market value as determined in accordance with
         GAAP; provided, however, that the following shall not in any event be
         deemed Eligible Inventory:

                           (1)  Inventory that is: in-transit; located at any
                  warehouse or other premises not approved by the Lender in
                  writing; located outside of the states, or localities, as
                  applicable, in which the Lender has filed financing statements
                  to perfect a first priority security interest in such
                  Inventory; covered by any negotiable or non-negotiable
                  warehouse receipt, bill of lading or other document of title;
                  on consignment from any Person; on consignment to any Person
                  or subject to any bailment unless such consignee or bailee has
                  executed an agreement with the Lender located at job sites;

                           (2)  Supplies, packaging or parts Inventory;

                           (3)  Work-in-process Inventory;

                           (4)  Inventory that is slow moving, damaged, obsolete
                  or not currently saleable in the normal course of the
                  Borrower's operations;

                           (5)  Inventory that the Borrower has returned, has
                  attempted to return, is in the process of returning or intends
                  to return to the vendor thereof;

                           (6)  Inventory that is subject to a security interest
                  in favor of any Person other than the Lender;

                           (7)  Inventory that is perishable or alive;

                           (8)  Sample Inventory;

                           (9) Inventory at a particular location if the value
                  of the same is less than 10% of total Inventory; and


                                      -2-

<PAGE>

                           (10) Inventory otherwise deemed ineligible by the
                  Lender in its sole discretion.

                  "Event of Default" has the meaning specified in Section 7.1.

                  "Floating Rate" means an annual rate equal to the sum of the
Prime Rate plus one and three-quarter percent (1.75%) which annual rate shall
change when and as the Prime Rate changes.

                  "GAAP" means generally accepted accounting principles, applied
on a basis consistent with the accounting practices applied in the financial
statements described in Section 5.2.

                  "Guarantor" means any person guaranteeing payment of the Note
or any of the other Obligations and any person executing any liquidation support
agreement in favor of the Lenders.

                  "Inventory" means all of the Borrower's inventory, as such
term is defined in the UCC, whether now owned or hereafter acquired.

                  "Loan Documents" means this Agreement, the Note, the
Disclosure, the Security Documents and any and all other related instruments,
agreements and documents executed by the Borrower, any Guarantor or any other
party and delivered to the Lender.

                  "Maximum Line" means $2,000,000.

                  "Note" means the Borrower's revolving promissory note, payable
to the order of the Lender in form and content satisfactory to Lender.

                  "Obligations" means each and every debt, liability and
obligation of every type and description which the Borrower may now or at any
time hereafter owe to the Lender, including all indebtedness arising under this
Agreement, the Note or any other loan or credit agreement or guaranty between
the Borrower and the Lender, whether now in effect or hereafter entered into.

                  "Person" means any individual, corporation, partnership, joint
venture, limited liability company, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

                  "Prime Rate" means the rate of interest publicly announced
from time to time by Wells Fargo Bank, N.A. as its "prime rate" or, if such bank
ceases to announce a rate so designated, any similar successor rate designated
by the Lender.

                  "Security Documents" means the Collateral Account Agreement
and the Lockbox Agreement, each of even date herewith and by and among the
Borrower, the Lender and Norwest Bank Minnesota, National Association and any
and all other documents, instruments and agreements executed by the Borrower or
any other party and delivered to the Lender as amended from time to time, as
security for the Obligations.

                  "Security Interest" has the meaning given in Section 3.1.

                  "Termination Date" has the meaning given in Section 2.4.

                  "UCC" means the Uniform Commercial Code as in effect from time
to time in the State of Minnesota.


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<PAGE>

                                   ARTICLE II

                     AMOUNT AND TERMS OF THE CREDIT FACILITY

                  Section II.1  REVOLVING ADVANCES.  The Lender may, in its sole
discretion, make advances to the Borrower from time to time from the date this
Agreement is signed and delivered to the Termination Date, on the terms and
subject to the conditions herein set forth (each an "Advance"). The Lender shall
not consider any request for an Advance if, after giving effect to such
requested Advance, the sum of the outstanding and unpaid Advances would exceed
the Borrowing Base. The Borrower's obligation to pay the Advances shall be
evidenced by the Note. Within the limits set forth in this Section 2.1, the
Borrower may request Advances, prepay, and request additional Advances. The
Borrower shall make each request for an Advance to the Lender before 11:00 a.m.
(Minneapolis time) of the day of the requested Advance. Requests may be made in
writing or by telephone.

                  Section II.2  INTEREST; DEFAULT INTEREST.

                  (a) REVOLVING NOTE. Except as set forth in Sections 2.2(b) and
2.2(c) the outstanding principal balance of the Advances shall bear interest at
the Floating Rate. All interest shall be payable monthly in arrears on the first
day of the month and on demand.

                  (b) MINIMUM INTEREST CHARGE. Notwithstanding the interest
payable pursuant to Section 2.2(a), the Borrower shall pay to the Lender
interest of not less than $80,000 per year during the term of this Agreement,
and on the last day of each year of this Agreement the Borrower shall pay any
deficiency between such minimum interest charge and the amount of interest
otherwise calculated under Sections 2.2(a) and 2.2(c).

                  (c) DEFAULT INTEREST RATE. From the first day of any month
during which Borrower is not in compliance with its agreements set forth in this
Agreement or the Note, in the Lender's discretion and without waiving any of its
other rights and remedies, the outstanding principal balance of the Advances
shall bear interest at the Default Rate.

                  Section II.3  FEES.

                  (a) CLOSING FEE. The Borrower agrees to pay the Lender a
closing fee of $10,000 upon the execution of this Agreement.

                  (b) MONITORING FEES. The Borrower agrees to pay the Lender
collateral monitoring fees for the expense of auditors (not to exceed the then
current standard applicable rate, which on the date of this Agreement is $62.50
per hour per auditor, plus out-of-pocket expenses).

                  Section II.4  DISCRETIONARY NATURE OF CREDIT FACILITY;
AUTOMATIC RENEWAL. THE LENDER MAY AT ANY TIME AND FOR ANY REASON REFUSE TO
MAKE AN ADVANCE AND/OR DEMAND PAYMENT OF THE ADVANCES AND TERMINATE THIS
AGREEMENT WHETHER BORROWER IS OR IS NOT IN COMPLIANCE WITH THIS AGREEMENT.
The Lender need not show that a material adverse change has occurred in the
Borrower's condition, financial or otherwise, in order to refuse to make any
requested Advance or to demand payment of the Advances. Unless terminated by
the Lender at any time or by the Borrower pursuant to Section 2.5, this
Agreement shall remain in effect until the one year anniversary of the date
of this Agreement and, thereafter, shall automatically renew for successive
one year periods. Each such anniversary date is herein referred to as a
"Termination Date".

                  Section II.5  TERMINATION BY BORROWER.

                  (a) TERMINATION BY BORROWER. The Borrower may terminate this
Agreement at any time subject to payment and performance of all Obligations, may
obtain any release or termination of the Security Interest to which the Borrower
is otherwise entitled by law by (1) giving at least 30 days' prior written
notice to the Lender of the Borrower's intention to terminate this Agreement,
and (2) paying the Lender a prepayment fee in accordance with Section 2.5(b) if
the Borrower terminates this Agreement effective as of any date other than a
Termination Date.


                                      -4-

<PAGE>

                  (b) PREPAYMENT FEE. If the Borrower desires to terminate this
Agreement as of a Termination Date but without giving at least 30 days' prior
written notice thereof, or if the Borrower desires to terminate this Agreement
as of any date other than a Termination Date upon giving at least 30 days' prior
written notice to the Lender of the Borrower's intention to do so, Borrower
shall pay to the Lender a prepayment fee of the greater of (i) 2% of the Maximum
Line or (ii) the Minimum Interest Charge pursuant to subsection 2.2(b) above
less the amount of interest actually paid by the Borrower since the date of this
Agreement, or, following automatic renewal pursuant to Section 2.4 above, since
the last Termination Date; provided that (i) no prepayment penalty shall be due
if the Borrower shall prepay the Obligations solely from cash flow generated
from the Borrower's operations in the ordinary course and (ii) no prepayment fee
shall be required if the prepayment is wholly made pursuant to a refinancing
with another "Norwest" affiliated entity.

                  Section II.6  MANDATORY PREPAYMENT.  Without notice or demand,
if the outstanding principal balance of the Advances shall at any time exceed
the Borrowing Base, the Borrower shall immediately prepay the Advances to the
extent necessary to eliminate such excess.

                  Section II.7  ADVANCES WITHOUT REQUEST.  The Borrower hereby
authorizes the Lender, in its discretion, at any time or from time to time
without the Borrower's request, to make Advances to pay accrued interest, fees,
uncollected items that have been applied to the Obligations, and other
Obligations due and payable from time to time.

                  Section 2.8  USE OF PROCEEDS.  The Borrower shall use the
proceeds of Advances for ordinary working capital purposes or the first Advance
hereunder shall be used to pay off the Borrower's existing obligations with
Bremer Business Finance Corp.


                                   ARTICLE III

                                SECURITY INTEREST

                  Section III.1  GRANT OF SECURITY INTEREST.  The Borrower
hereby grants to the Lender a security interest (the "Security Interest") in
the following collateral (the "Collateral"), as security for the payment and
performance of the Obligations:

         INVENTORY: All inventory of Borrower, as such term is defined in the
         UCC, whether now owned or hereafter acquired, whether consisting of
         whole goods, spare parts or components, supplies or materials, whether
         acquired, held or furnished for sale, for lease or under service
         contracts or for manufacture or processing, and wherever located; and

         ACCOUNTS AND OTHER RIGHTS TO PAYMENT: Each and every right of Borrower
         to the payment of money, whether such right to payment now exists or
         hereafter arises, whether such right to payment arises out of a sale,
         lease or other disposition of goods or other property, out of a
         rendering of services, out of a loan, out of the overpayment of taxes
         or other liabilities, or otherwise arises under any contract or
         agreement, whether such right to payment is created, generated or
         earned by Borrower or by some other person who subsequently transfers
         such person's interest to Borrower, whether such right to payment is or
         is not already earned by performance, and howsoever such right to
         payment may be evidenced, together with all other rights and interests
         (including all liens and security interests) which Borrower may at any
         time have by law or agreement against any account debtor or other
         obligor obligated to make any such payment or against any property of
         such account debtor or other obligor; all including all of Borrower's
         rights to payment in the form of all present and future accounts,
         contract rights, loans and obligations receivable, chattel papers,
         bonds, notes and other debt instruments, tax refunds and rights to
         payment in the nature of general intangibles; and

         EQUIPMENT: All of the Borrower's goods and equipment, as such term is
         defined in the UCC whether now or hereafter owned, including all
         present and future machinery, vehicles, furniture, fixtures,
         manufacturing equipment, shop equipment, office and recordkeeping
         equipment, parts, tools, supplies, and including specifically the goods
         described in any equipment schedule or list herewith or hereafter
         furnished to the Lender by the Borrower;

         INVESTMENT PROPERTY: All of the Borrower's investment property, as such
         term is defined in the UCC, including without limitation securities,
         securities accounts, securities entitlements, financial assets and
         certificates of deposit of the Borrower and


                                      -5-

<PAGE>

         all funds of the Borrower on deposit with and all property in the
         possession of the Lender or any depository institution, each whether
         now owned or hereafter acquired; and

         GENERAL INTANGIBLES: All of the Borrower's general intangibles, as such
         term is defined in the UCC, whether now owned or hereafter acquired,
         including all present and future contract rights, patents, patent
         applications, copyrights, trademarks, trade names, trade secrets,
         customer or supplier lists and contracts, manuals, operating
         instructions, permits, franchises, the right to use the Borrower's
         name, and the goodwill of Borrower's business; and

         PROCEEDS: Together with all substitutions and replacements for and
         products of any of the foregoing property and together with proceeds of
         any and all of the foregoing property and, in the case of all tangible
         property, together with all accessions and together with (i) all
         accessories, attachments, parts, equipment and repairs now or hereafter
         attached or affixed to or used in connection with any such tangible
         property, and (ii) all warehouse receipts, bills of lading and other
         documents of title now or hereafter covering such tangible property.

                  Section III.2  NOTIFICATION OF ACCOUNT DEBTORS AND OTHER
OBLIGORS.  The Lender may at any time (either before or after the occurrence of
an Event of Default) notify any account debtor or other person obligated to pay
the amount due that such right to payment has been assigned or transferred to
the Lender for security and shall be paid directly to the Lender. The Borrower
will join in giving such notice if the Lender so requests. At any time after the
Borrower or the Lender gives such notice to an account debtor or other obligor,
the Lender may, but need not, as the Borrower's agent and attorney-in-fact,
notify the United States Postal Service to change the address for delivery of
the Borrower's mail to any address designated by the Lender, otherwise intercept
the Borrower's mail, and receive, open and dispose of the Borrower's mail,
applying all Collateral as permitted under this Agreement and holding all other
mail for the Borrower's account or forwarding such mail to the Borrower's last
known address.

                  Section III.3  OCCUPANCY.

                   (a) The Borrower hereby irrevocably grants to the Lender the
right to take possession of each premises where Borrower conducts its business
and has any rights of possession (the "Premises") at any time after the
occurrence and during the continuance of an Event of Default.

                  (b) The Lender may use the Premises only to hold, process,
manufacture, sell, use, store, liquidate, realize upon or otherwise dispose of
goods that are Collateral and for other purposes that the Lender in good faith
considers related.

                  (c) The Lender's right to hold the Premises shall terminate
upon the earlier of payment in full of all Obligations, or final sale or
disposition of all goods constituting Collateral and delivery of all such goods
to purchasers.

                  (d) The Lender shall not be obligated to pay or account for
any rent or other compensation for the possession or use of any of the Premises;
provided, however, that if the Lender does pay or account for any rent or other
compensation for the possession or use of any of the Premises, the Borrower
shall reimburse the Lender promptly for the full amount thereof.

                  Section III.4  LICENSE/MAINTENANCE OF INTELLECTUAL
PROPERTY. The Borrower hereby grants to the Lender a non-exclusive, worldwide
and royalty-free license to use or otherwise exploit all trademarks,
franchises, trade names, copyrights and patents owned by or licensed to the
Borrower for the purpose of selling, leasing or otherwise disposing of any or
all Collateral following an Event of Default. The Borrower shall not sell,
transfer, assign (by operation of law or otherwise), exchange, lease,
license, allow to go abandoned or otherwise dispose of all or any portion of
said intellectual property and shall maintain and protect all of such
property in accordance with all applicable state, federal and foreign laws.

                  Section III.5  FILING A COPY.  A carbon, photographic, or
other reproduction of this Agreement or of a financing statement signed by
Borrower is sufficient as a financing statement.


                                      -6-

<PAGE>

                                   ARTICLE IV

                              CONDITIONS OF LENDING

                  In view of the fact that Advances may be made in the sole
discretion of the Lender, this Agreement does not set forth conditions precedent
to Advances. The Lender will advise the Borrower of the Lender's documentation
and other requirements before considering any Advance.


                                    ARTICLE V

                         REPRESENTATIONS AND WARRANTIES

                  The Borrower represents and warrants to the Lender as follows:

                  Section V.1  NAME; LOCATIONS; TAX ID NO., SUBSIDIARIES.
During its existence, the Borrower has done business solely under its
corporate name as set forth herein and under such trade names and such other
corporate names as disclosed to Lender in writing before this Agreement is
signed and delivered. The address of Borrower's chief executive office and
principal place of business and its federal tax identification number are set
forth below its signature to this Agreement. All Inventory is located at that
location or at one of the other locations disclosed to Lender in writing
before this Agreement is signed and delivered. The Borrower has no
subsidiaries except as disclosed to Lender in writing before this Agreement
is signed and delivered.

                  Section V.2  FINANCIAL CONDITION; NO ADVERSE CHANGE.  Before
this Agreement was signed and delivered, the Borrower furnished the Lender
certain of its unaudited financial statements certified by the Borrower. Those
statements fairly present the Borrower's financial condition as the dates
indicated therein and the results of its operations for the period ended March
31, 1999 and were prepared in accordance with generally accepted accounting
principles. Since March 31, 1999, there has been no material adverse change in
the business, properties or condition (financial or otherwise) of the Borrower.


                                   ARTICLE VI

                      AFFIRMATIVE COVENANTS OF THE BORROWER

                  So long as the Advances or any other obligations shall
remain unpaid, the Borrower will comply with the requirements in this
Article, unless the Lender shall otherwise consent in writing.

                  Section VI.1  REPORTING REQUIREMENTS.  The Borrower will
deliver to the Lender each of the following in form and detail acceptable to
the Lender:

                  (a) as soon as available, and in any event within 90 days
         after the end of each fiscal year of the Borrower, the Borrower's
         audited financial statements prepared in accordance with GAAP;

                  (b) as soon as available and in any event within 20 days after
         the end of each month, an unaudited/internal balance sheet and
         statement of income and retained earnings of the Borrower as at the end
         of and for such month and for the year to date period then ended,
         prepared in accordance with GAAP, subject to year-end audit
         adjustments, together with a completed compliance certificate in the
         form attached hereto;

                  (c) within fifteen (15) days after the end of each month,
         agings of the Borrower's accounts receivable, together with a
         certificate of ineligible accounts, and agings of the Borrower's
         accounts payable, each as of the end of such month;

                  (d) not later than fifteen (15) days after each month end or
         more frequently if requested by the Lender, inventory certifications
         and a detailed inventory report by the Borrower, each in form
         acceptable to the Lender, for such month and/or other period, as
         applicable;


                                      -7-

<PAGE>

                  (e) as soon as available, and within fifteen (15) days of
         receipt thereof, a copy of the bank account statements of the Borrower
         from each bank with which Borrower maintains an account;

                  (f) from time to time, with reasonable promptness, any and all
         receivables schedules, collection reports, deposit records, equipment
         schedules, copies of invoices to account debtors, shipment documents
         and delivery receipts for goods sold, and such other material, reports,
         records or information as the Lender may request;

                  (g) within three (3) days of Borrower's payment of or deposit
         for taxes, including but not limited to payroll taxes, proof of such
         payment in form acceptable to the Lender;

                  (h) at least thirty (30) days before the beginning of each of
         Borrower's fiscal years, projections of Borrower's monthly balance
         sheets and income statements for such fiscal year; and

                  (i) immediately after the commencement thereof, notice in
         writing of all litigation and of all proceedings before any
         governmental or regulatory agency affecting the Borrower or which seek
         a monetary recovery against the Borrower in excess of $10,000.

                  Section VI.2  INSPECTION.  Upon the Lender's request, the
Borrower will permit any officer, employee, attorney, agent or accountant for
the Lender to audit, review, make extracts from or copy any and all records of
the Borrower and to inspect the Collateral at all times during ordinary business
hours.

                  Section VI.3  ACCOUNT VERIFICATION.  The Borrower will at any
time and from time to time upon request of the Lender send requests for
verification of Accounts or notices of assignment to account debtors and other
obligors. The Borrower authorizes the Lender to verify Accounts directly with
account debtors or other obligors from time to time, including on a daily basis
(and the Borrower understands the Lender intends to do so by telephone and/or in
writing).

                  Section VI.4  NO OTHER LIENS.  The Borrower will keep all
Collateral free and clear of all security interests, liens and encumbrances
except the Security Interest, purchase money security interests in equipment,
and other security interests approved by the Lender in writing.

                  Section VI.5  INSURANCE.  The Borrower will at all times keep
all tangible Collateral insured against risks of fire (including so-called
extended coverage), theft, collision (for Collateral consisting of motor
vehicles) and such other risks and in such amounts as the Lender may reasonably
request, with a lender's loss payable clause in favor of Lender to the extent of
its interest.

                  Section VI.6  LOCKBOX; COLLATERAL ACCOUNT.  The Borrower
has provided the Lender with agreements regarding a lockbox and a collateral
account in connection with the collection of Accounts.

                  Section VI.7  MINIMUM BOOK NET INCOME.  The Borrower will
at all times maintain during each period described below, a Book Net Income
(on an unconsolidated, Borrower-only basis), determined on a year-to-date
basis as of the end of each month, of at least the amount set forth opposite
such period (bracketed amounts indicated Maximum Book Net Loss):

<TABLE>
<CAPTION>

                        Period                     Minimum Book Net Income
                        <S>                        <C>
                        March, 1999                       < $270,000 >

                        April, 1999                       < $320,000 >

                        May, 1999                         < $300,000 >

                        June, 1999                        < $230,000 >

                        July, 1999                        < $250,000 >


                                      -8-

<PAGE>

                        August, 1999                      < $170,000 >

                        September, 1999                    < $80,000 >

                        October, 1999                      < $30,000 >

                        November, 1999                     < $45,000 >

                        December, 1999                     < $70,000 >

</TABLE>

Lender shall reset the Book Net Income covenant levels based on Borrower's
projections provided pursuant to Section 6.1(h).

                  Section VI.8  NO SALE OR TRANSFER OF COLLATERAL AND OTHER
ASSETS.  The Borrower will not sell, lease, assign, transfer or otherwise
dispose of (i) the stock of any subsidiary, (ii) all or a substantial part of
its assets, or (iii) any Collateral or any interest therein (whether in one
transaction or in a series of transactions) to anyone other than the sale of
Inventory in the ordinary course of business.

                  Section VI.9  PLACE OF BUSINESS; NAME.  The Borrower will
not change the location of its chief executive office or principal place of
business from that disclosed pursuant to Section 5.1. The Borrower will not
permit any tangible Collateral to be located in any state or area in which,
in the event of such location, a financing statement covering such Collateral
would be required to be, but has not in fact been, filed in order to perfect
the Security Interest. The Borrower will not change its name.

                  Section VI.10  Y2K COMPLIANCE.  The Borrower will maintain its
systems in compliance with "Y2K" requirements no later than September 30, 1999.

                  Section VI.11  DIVIDEND RESTRICTION.  The Borrower will not
purchase or redeem any shares of Borrower's stock or declare or pay any
dividends (other than dividends payable in stock) or make any distributions to
stockholders of any assets of the Borrower or make any distribution which would
result in an Event of Default, except Borrower may pay dividends on its Class A
and Class B Preferred Stock.

                  Section VI.12  UNFINANCED CAPITAL EXPENDITURES.  The Borrower
will not expend or contract to expend more than $100,000 in the aggregate during
any fiscal year for fixed assets, including Equipment, except for capital
expenditures financed through long term debt.

                  Section 6.13.  TRANSACTIONS WITH AFFILIATES.  The Borrower
will not make investments in any Affiliate of the Borrower, and will not
extend credit to or become indebted to any Affiliate of the Borrower except
in the ordinary course of business for fair consideration upon terms not less
favorable than would be available in an arm's-length transaction with an
unrelated third party. For the purposes of this Section 6.13, "Affiliate"
shall include, with respect to any party, any Person which directly or
indirectly controls, is controlled by, or is under common control os such
party and, in addition, in the case of Borrower, each director, shareholder,
joint venturer or partner of the Borrower. Without limitation, Vicom Midwest
Telecommunication Systems, Inc. and Nationwide Communications, Inc. shall be
Affiliates.


                                   ARTICLE VII

                     EVENTS OF DEFAULT, RIGHTS AND REMEDIES

                  Section VII.1  EVENTS OF DEFAULT.  An "Event of Default" as
used herein shall mean any of the following:

                  (a) Failure to pay the Note when demanded, and in this
         connection Borrower hereby waives presentment, notice of dishonor and
         protest;

                  (b) A petition shall be filed by or against the Borrower or
         any Guarantor under the United States Bankruptcy Code naming the
         Borrower or such Guarantor as debtor;


                                      -9-

<PAGE>

                  (c) Default in the performance, or breach, of any covenant or
         agreement of the Borrower, any Guarantor or any other related party
         contained in this Agreement or any other Loan Document.

                  Section VII.2  RIGHTS AND REMEDIES.  As provided in Section
2.4, the Lender may, at any time and for any reason, refuse to make any
requested Advance or demand payment of the Advances. Upon such demand or upon
the occurrence of an Event of Default or at any time thereafter, the Lender
may exercise any or all of the following rights and remedies:

                  (a) The Lender may exercise and enforce any and all rights and
         remedies available upon default to a secured party under the UCC,
         including the right to take possession of Collateral, or any evidence
         thereof, proceeding without judicial process or by judicial process
         (without a prior hearing or notice thereof, which the Borrower hereby
         expressly waives) and the right to sell, lease or otherwise dispose of
         any or all of the Collateral, and in connection therewith, the Borrower
         will on demand assemble the Collateral and make it available to the
         Lender at a place to be designated by the Lender which is reasonably
         convenient to both parties;

                  (b) the Lender may exercise any other rights and remedies
         available to it by law or agreement.

The remedies provided hereunder are cumulative.

                  Section VII.3  CERTAIN NOTICES.  If notice to the Borrower of
any intended disposition of Collateral or any other intended action is required
by law in a particular instance, such notice shall be deemed commercially
reasonable if given (in the manner specified in Section 8.1) at least 10
calendar days before the date of intended disposition or other action.


                                  ARTICLE VIII

                                  MISCELLANEOUS

                  Section VIII.1  ADDRESSES FOR NOTICES, ETC.  Except as
otherwise expressly provided herein, all notices, requests, demands and other
communications provided for hereunder shall be in writing and shall be
(a) personally delivered, (b) sent by first class United States mail,
(c) sent by overnight courier of national reputation, or (d) transmitted by
telecopy, in each case addressed or telecopied to the party to whom notice is
being given at its address or telecopy number as set forth below its
signature to this Agreement.

                  Section VIII.2  COSTS AND EXPENSES.  The Borrower agrees to
pay on demand all costs and expenses (including legal fees) incurred by the
Lender in connection with the Loan Documents, and any other document or
agreement related thereto, and the transactions contemplated hereby,
including wire transfer and ACH charges, the cost of credit reports,
overadvance fees, the expense of any auditors (not to exceed the then current
standard applicable rate, which on the date of this Agreement is $62.50 per
hour per auditor, plus out of pocket expenses), and fees and expenses in
enforcing this Agreement.

                  Section VIII.3  INDEMNITY.  In addition to the payment of
expenses pursuant to Section 8.2, the Borrower agrees to indemnify, defend and
hold harmless the Lender, and any of its participants, parent corporations,
subsidiary corporations, affiliated corporations, successor corporations, and
all present and future officers, directors, employees, attorneys and agents of
the foregoing (the "Indemnitees") from and against any of the following
(collectively, "Indemnified Liabilities"):

                  (1) any and all transfer taxes, documentary taxes, assessments
         or charges made by any governmental authority by reason of the
         execution and delivery of this Agreement and the other Loan Documents
         or the making of the Advances;

                  (2) any and all liabilities, losses, damages, penalties,
         judgments, suits, claims, costs and expenses of any kind or nature
         whatsoever (including, without limitation, the reasonable fees and
         disbursements of counsel) in connection with any investigative,
         administrative or judicial proceedings, whether or not such Indemnitee
         shall be designated a party thereto, which may be imposed on, incurred
         by or asserted against any such Indemnitee, in any manner related to or
         arising out of or in


                                     -10-

<PAGE>

         connection with the making of the Advances, this Agreement and the
         other Loan Documents or the use or intended use of the proceeds of
         the Advances; and

                  (3) any claim, loss or damage to which any Indemnitee may be
         subjected as a result of any violation of any federal, state, local or
         other governmental statute, regulation, law, or ordinance dealing with
         the protection of human health and the environment, in any manner
         related to or arising out of or in connection with the making of the
         Advances, this Agreement and the other Loan Documents or the use or
         intended use of the proceeds of the Advances.

If any investigative, judicial or administrative proceeding arising from any of
the foregoing is brought against any Indemnitee, the Borrower, or counsel
designated by the Borrower and satisfactory to the Indemnitee, will resist and
defend such action, suit or proceeding to the extent and in the manner directed
by the Indemnitee. Each Indemnitee will use its best efforts to cooperate in the
defense of any such action, suit or proceeding. If the foregoing undertaking to
indemnify, defend and hold harmless may be held to be unenforceable because it
violates any law or public policy, the Borrower shall nevertheless make the
maximum contribution to the payment and satisfaction of each of the Indemnified
Liabilities which is permissible under applicable law. The Borrower's obligation
under this Section 8.3 shall survive the termination of this Agreement and the
discharge of the Borrower's other obligations hereunder.

                  Section VIII.4  BINDING EFFECT; ASSIGNMENT; SHARING OF
INFORMATION.  The Loan Documents shall be binding upon and inure to the benefit
of the Borrower and the Lender and their respective successors and assigns,
except that the Borrower shall not have the right to assign its rights
thereunder or any interest therein without the prior written consent of the
Lender. Without limitation of the Lender's right to share information regarding
the Borrower and its Affiliates with Lender's participants, accountants, lawyers
and other advisors, the Lender may share at any time with Norwest Corporation,
and all direct and indirect subsidiaries of Norwest Corporation, any and all
information the Lender may have in its possession regarding the Borrower and its
Affiliates, and the Borrower waives any right of confidentiality it may have
with respect to such sharing of information.

                  Section VIII.5  GOVERNING LAW; JURISDICTION, VENUE; WAIVER OF
JURY TRIAL.  This Agreement and the Note shall be governed by and construed in
accordance with the laws (other than conflict laws) of the State of Minnesota.
Each party consents to the personal jurisdiction of the state and federal courts
located in the State of Minnesota in connection with any controversy related to
this Agreement, waives any argument that venue in any such forum is not
convenient and agrees that any litigation initiated by any of them in connection
with this Agreement shall be venued in either the District Court of Hennepin
County, Minnesota located in Minneapolis, Minnesota, or the United States
District Court, District of Minnesota, Fourth Division. THE PARTIES WAIVE ANY
RIGHT TO TRIAL BY JURY IN ANY ACTION OR PROCEEDING BASED ON OR PERTAINING TO
THIS AGREEMENT.




                            [SIGNATURE PAGE FOLLOWS]


                                     -11-

<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have signed this
Agreement as of the date first above written.


WELLS FARGO BUSINESS CREDIT, INC.              VICOM, INCORPORATED


By                                             By
  -------------------------------                 -----------------------------
  Roger Pfiffner                                  Steven Bell
  Its Vice President                              Its President

Address:                                       Address:
Norwest Center                                 9449 Science Center Drive
Sixth Street and Marquette Avenue              New Hope, Minnesota 55428
Minneapolis, Minnesota 55479-0152
                                               Telecopy No.  612-504-3060
Telecopy No. (612) 341-2472                    Federal Tax I.D. No. 41-1255001
Federal Tax ID No. 41-1712687




                [Signature Page to Credit and Security Agreement]


                                     -12-

<PAGE>

                             COMPLIANCE CERTIFICATE


To:               Michael Guillou
                  Wells Fargo Business Credit, Inc.

Date:             __________________, _______

Subject:          VICOM, Incorporated Financial Statements

                  In accordance with our Credit and Security Agreement dated as
of June 17, 1999 (the "Credit Agreement"), attached are the financial statements
of VICOM, Incorporated (the "Borrower") as of and for ________________, 19___
(the "Reporting Date") and the year-to-date period then ended (the "Current
Financials"). All terms used in this certificate have the meanings given in the
Credit Agreement.

                  I certify that the Current Financials have been prepared in
accordance with GAAP, subject to year-end audit adjustments, and fairly present
the Borrower's financial condition as of the date thereof.

                  EVENTS OF DEFAULT.  (Check one):

         / /      The undersigned does not have knowledge of the occurrence of a
                  Default or Event of Default under the Credit Agreement.

         / /      The undersigned has knowledge of the occurrence of a Default
                  or Event of Default under the Credit Agreement and attached
                  hereto is a statement of the facts with respect to thereto.

                  REPRESENTATION AND WARRANTIES. (Check one):

         / /      The undersigned hereby reaffirms the representations and
                  warranties as set forth in the Credit Agreement, each of which
                  are true and correct as of the date hereof.

         / /      The undersigned hereby reaffirms the representations and
                  warranties set forth in the Credit Agreement, each of which
                  are true and correct as of the date hereof except as described
                  in the statement attached hereto.

                  FINANCIAL COVENANTS.  I further hereby certify as follows:

                  1.  MINIMUM BOOK NET INCOME.  Pursuant to Section 6.7 of the
         Credit Agreement, as of the Reporting Date, the Borrower's Book Net
         Income was $____________, which G satisfies G does not satisfy the
         requirement that such amount be not less than $_____________ on the
         Reporting Date as set forth in table below:

<TABLE>
<CAPTION>

            Period                       Minimum Book Net Income
            <S>                          <C>
            March, 1999                         < $270,000 >

            April, 1999                         < $320,000 >

            May, 1999                           < $300,000 >

            June, 1999                          < $230,000 >


                                     -2-

<PAGE>

            July, 1999                          < $250,000 >

            August, 1999                        < $170,000 >

            September, 1999                      < $80,000 >

            October, 1999                        < $30,000 >

            November, 1999                       < $45,000 >

            December, 1999                       < $70,000 >

</TABLE>

                  Attached hereto are all relevant facts in reasonable detail to
evidence, and the computations of the financial covenants referred to above.
These computations were made in accordance with GAAP.


                                            VICOM, INCORPORATED

                                            By
                                               --------------------------------
                                               Thomas S. Wargolet
                                               Its Chief Financial Officer


                                     -3-