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                                                                     EXHIBIT 5.1



                       [Palmer & Dodge Letterhead]



September 11, 1997
ILL Systems, Inc.
124 Acton Street
Maynard, Massachusetts  01754


Ladies and Gentlemen:

      We are rendering this opinion in connection with the Registration
Statement on Form S-8 (the "Registration Statement") filed by IPL Systems, Inc.
(the "Company") with the Securities and Exchange Commission under the Securities
Act of 1933, as amended (the "Act"), on or about the date hereof. The
Registration Statement relates to 654,500 shares (the "Shares") of the Company's
Class A Common Stock, $.01 par value, offered pursuant to the provisions of the
Company's 1996 Consolidated Equity Incentive Plan (the "Plan").

      In connection with this opinion, we have examined and relied upon the
Registration Statement, the Plan, the Company's Restated Articles of
Organization, and Bylaws, as amended, and the originals or copies certified to
our satisfaction of such records, documents, certificates, memoranda and other
instruments as in our judgment are necessary or appropriate to enable us to
render the opinion expressed below. We have assumed the genuineness and
authenticity of all documents submitted to us as originals, the conformity to
originals of all documents submitted to us as copies thereof and the due
execution and delivery of all documents where due execution and delivery are a
prerequisite to the effectiveness thereof.

      Based upon the foregoing, we are of the opinion that, when issued in
accordance with the terms of the Plan and the options or other rights granted
thereunder, the Shares will be duly authorized, validly issued, fully paid and
nonassessable.

      We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                          Very truly yours,



                                          Palmer & Dodge LLP