EXHIBIT 15 Securities and Exchange Commission 450 Fifth Street N.W. Washington, D.C. 20549 We are aware that our report dated July 31, 1997 on our reviews of interim condensed consolidated financial information of Digi International Inc. and subsidiaries (the Company) for the three and nine month periods ended June 30, 1997 and 1996, and included in the Company's Form 10-Q for the quarter ended June 30, 1997, is incorporated by reference in the Company's registration statements on Form S-8 (Registration Nos. 33-32956, 33-38898, 333-99, and 333-1821) and Form S-3 (Registration No. 33-59223). Pursuant to Rule 436(c), under the Securities Act of 1933, this report should not be considered a part of the registration statements prepared or certified by us within the meaning of Sections 7 and 11 of that Act. COOPERS & LYBRAND L.L.P. Minneapolis, Minnesota August 8, 1997