<PAGE>

                              LEASE AMENDMENT ONE

                            (EXPANSION OF PREMISES)

     THIS AMENDMENT ONE ("AMENDMENT") is made and entered as of the 4th day of
March, 1997, by and between TOWN CENTER DELAWARE, INC., a Delaware corporation
("LANDLORD"), and ELTRAX SYSTEMS, INC., a Minnesota corporation ("TENANT").

     A.   Landlord's predecessor in interest, PMTC Limited Partnership, and
Tenant have heretofore entered into that certain Town Center Office Lease dated
as of May 20, 1996, for premises described as Suite 690 (the "PREMISES"),
initially containing approximately 1,095 rentable square feet in the property
(the "PROPERTY") known as 2000 Town Center located at 2000 Town Center,
Southfield Michigan (collectively, the "LEASE").

     B.   Tenant has requested that additional space currently known as Suite
682 (the "EXPANSION PREMISES"), located on the sixth floor of the Property and
consisting of approximately 1,092 rentable square feet for purposes hereof, be
added to the Premises, and Landlord is willing to grant the same, all on the
terms and conditions hereinafter set forth.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements
herein contained, and other good and valuable consideration, the parties do
hereby agree that the Lease shall be, and hereby is, modified as follows:

     I.   MODIFICATIONS TO LEASE SCHEDULE.  Commencing on the Expansion Date
set forth below (or such other date for any particular Item specifically set
forth herein), the Schedule set forth on the first page of the Lease shall be
modified with respect to the following items (such modifications to the
Schedule are hereinafter referred to as the "REVISED SCHEDULE"):

                               REVISED SCHEDULE

          2.   Rentable Square Feet of Premises:  2,187

          4.   Base Rent:

                      Period                  Monthly          Annually
                --------------------         ---------        ----------
                06/01/97 to 05/31/98         $2,004.25        $24,051.00
                06/01/98 to 05/31/99         $2,049.81        $24,597.72
                06/01/99 to 05/31/00         $2,094.56        $25,134.72
                06/01/00 to 05/31/01         $2,140.94        $25,691.28

          5.   Tenant's Share:               0.421%

          6.   Security Deposit              $3,550.00 (Tenant shall pay an
                                             additional amount of $1,998.75 upon


                                       1
<PAGE>
                                             Tenant's execution of this
                                             Amendment)

          7.   Broker(s)                     Premisys Real Estate Services, Inc.

          8.   Expansion Date                June 1, 1997, subject to the
                                             provisions below

          13.  Exhibits                      EXHIBIT A hereto shall replace
                                             EXHIBIT A attached to the Lease

                                             EXHIBIT B (Construction Workletter)
                                             attached to the Lease shall not be
                                             applicable to the Expansion
                                             Premises and is hereby deleted

     The foregoing provisions are intended to supplement, and supersede in cases
of inconsistency, the corresponding provisions of the Lease, and shall be
interpreted and applied in accordance with the other provisions of this
Amendment and the Lease.  Capitalized terms not otherwise defined herein shall
have the meanings ascribed thereto in the Lease.

     II.  OTHER LEASE MODIFICATIONS.  The parties hereby agree as follows:

          1.   Section 28 (Termination Option) of the Lease is hereby deleted.

     III. EXPANSION.  Commencing on the Expansion Date set forth above (but
subject to adjustment as provided herein), the Expansion Premises described
above shall be added to and shall become a part of the Premises, subject to the
terms and conditions set forth herein.

     IV.  PRORATIONS.  If the Expansion Date occurs other than on the
beginning of the applicable payment period under the Lease, Tenant's obligations
for Base Rent, Taxes, Expenses and other such charges shall be prorated on a per
diem basis.

     V.   POSSESSION AND CONDITION OF EXPANSION PREMISES.  Tenant has inspected
the Expansion Premises and agrees to accept the same "AS IS" without any
agreements, representations, understandings or obligations on the part of
Landlord to perform any alterations, repairs or improvements, or any allowance
therefor.  Any construction, alterations or improvements made to the Expansion
Premises by Tenant shall be subject to Landlord's prior written approval
including without limitation, approval of the plans, specifications, contractors
and subcontractors therefor, and all applicable terms and conditions of the
Lease relating to construction, alterations or improvements of the Premises, and
such other reasonable requirements or conditions as Landlord may impose.  During
any period that Tenant shall be permitted to enter the Expansion Premises prior
to the Expansion Date other than to occupy the same (e.g., to perform
alterations or improvements), Tenant shall comply with all terms and provisions
of the Lease, except that the Base Rent and Tenant's Share under the Revised
Schedule shall not apply.  If Tenant shall be


                                       2
<PAGE>

permitted to enter the Expansion Premises prior to the Expansion Date for the
purpose of occupying the same, the Revised Schedule shall commence on such
date; if Tenant shall commence occupying only a portion of the Expansion
Premises prior to the Expansion Date, such rent and charges shall be prorated
based on the number of rentable square feet occupied by Tenant.

     VI.  DELAYS.  The Expansion Date shall be delayed and the Base Rent and
Tenant's Share under the Revised Schedule shall be postponed (and Tenant shall
continue paying in accordance with the original Schedule) to the extent that
Landlord fails to deliver possession of the Expansion Premises for any reason,
including but not limited to holding over by prior occupants, except to the
extent that Tenant, its contractors, agents or employees in any way contribute
to such failure.  If Landlord so fails for a ninety (90) day initial grace
period, or such additional time as may be necessary due to acts or omissions of
Tenant, its contractors, agents or employees, or other causes beyond Landlord's
reasonable control, Tenant shall have the right to terminate this Amendment by
written notice to Landlord within ten (10) days thereafter unless Landlord
delivers possession within ten (10) days after receiving Tenant's notice.  Any
such delay in the Expansion Date shall not subject Landlord to any liability for
any loss or damage resulting therefrom, and Tenant's sole remedy with respect
thereto shall be the abatement of Base Rent and Tenant's Share under the Revised
Schedule and right to terminate this Amendment described above.  If the
Expansion Date is delayed, the Expiration Date under the Lease shall not be
similarly extended (unless Landlord so elects in writing).  TENANT HEREBY
ACKNOWLEDGES THAT LANDLORD WILL NEED TO GIVE 60 DAYS' NOTICE OF TERMINATION TO
THE EXISTING TENANT OF THE EXPANSION PREMISES, AND THAT LANDLORD WILL NOT GIVE
SUCH NOTICE UNTIL THIS AMENDMENT IS SIGNED AND DELIVERED BY BOTH PARTIES.

     VII. OTHER TERMS.  On the Expansion Date, the Expansion Premises shall
be added to the Premises under the Lease, and all terms and conditions then or
thereafter in effect under the Lease shall apply to the Expansion Premises,
except as otherwise expressly provided to the contrary herein.  Notwithstanding
the foregoing to the contrary, this Amendment is intended to supersede any
rights of Tenant under the Lease to expand or relocate the Premises, or
terminate the Lease early, and all such provisions are hereby deleted.  In
addition, any rights of Tenant under the Lease to extend the term shall with
respect to the Expansion Premises shall be subordinate to, and limited by, any
rights of any other parties to lease the Expansion Premises granted prior to
full execution and delivery of this Amendment.

     VIII.CONFIDENTIALITY.  Tenant shall keep the content and all copies of
this document and the Lease, all related documents or agreements now or
hereafter entered, and all proposals, materials, information and matters
relating thereto strictly confidential, and shall not disclose, disseminate or
distribute any of the same, or permit the same to occur, with respect to any
party other than Tenant's financial or legal advisors to the extent that they
need such information to advise Tenant (and Tenant shall obligate any such other
parties to whom disclosure is permitted to honor the confidentiality provisions
hereof), except as may be required by Law or court proceedings.


                                       3
<PAGE>

     IX.  REAL ESTATE BROKERS.  Tenant represents and warrants that Tenant has
not dealt with any broker, agent or finder in connection with this Amendment
other than the broker(s), if any, set forth above (whom Landlord shall pay
pursuant to separate written agreement(s), if any), and agrees to indemnify and
hold Landlord, and it employees, agents and affiliates harmless from all
damages, judgments, liabilities and expenses (including reasonable attorneys'
fees) arising from any claims or demands of any other broker, agent or finder
with whom Tenant has dealt for any commission or fee alleged to be due in
connection with this Amendment.

     X.   CONSENT.  This Amendment is subject to and conditioned upon, any
required consent or approval being granted without any fee, charge or condition
that is unacceptable to Landlord, by Landlord's mortgagees, ground lessors or
partners. If any such consents shall be denied or granted subject to the payment
of unacceptable fees, charges or conditions, the Lease shall remain in full
force and effect, without the modifications provided herein.

     XI.  OFFER.  The submission and negotiation of this Amendment shall not be
deemed an offer to enter the same by Landlord.  Tenant's execution of this
Amendment constitutes a firm offer to enter the same which may not be withdrawn
for a period of forty-five (45) days after delivery to Landlord.  During such
period, Landlord may proceed in reliance thereon and permit Tenant to enter the
Expansion Premises, but such acts shall not be deemed an acceptance.  Such
acceptance shall be evidenced only by Landlord signing and delivering this
Amendment to Tenant.

     XII. WHOLE AMENDMENT.  This Amendment sets forth the entire agreement
between the parties with respect to the matters set forth herein.  There have
been no additional oral or written


                      [This Space Left Intentionally Blank]


                                       4
<PAGE>

representations or agreements.  In case of any inconsistency between the
provisions of the Lease and this Amendment, the latter provisions shall govern
and control.

     IN WITNESS WHEREOF, the Landlord and Tenant have duly executed this
Amendment as of the day and year first above written.

                                   LANDLORD:
                                   --------

                                   TOWN CENTER DELAWARE, INC., a Delaware
                                   corporation


                                   By:  /s/  Thomas Lee
                                      ---------------------------------
                                   Name:     Thomas Lee
                                         ------------------------------
                                   Title:    Authorized Signatory
                                         ------------------------------


                                   By:  /s/  Tia S. Miyamoto
                                      ---------------------------------
                                   Name:     Tia S. Myamoto
                                        -------------------------------
                                   Title:    Authorized Signatory
                                        -------------------------------


                                   TENANT:
                                   ------

                                   ELTRAX SYSTEMS, INC., a Minnesota corporation


                                   By:  /s/  Clunet R. Lewis
                                      ---------------------------------
                                   Name:     Clunet R. Lewis
                                        -------------------------------
                                   Title:    Chief Financial Officer
                                        -------------------------------


                                       5