EXHIBIT 23.1

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Consent of Independent Registered Public Accounting Firm

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We consent to the incorporation by reference in these Registration Statements (Nos. 333-64493, 333-124030, 333-124031, 333-151024, 333-197608, 333-207229, and 333-231650) on Form S-8 of CSP Inc. and Subsidiaries of our report dated December 28, 2020, relating to the consolidated financial statements of CSP Inc. and Subsidiaries, appearing in this Annual Report on Form 10-K of CSP Inc. for the year ended September 30, 2020.

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/s/ RSM US LLP

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Boston, Massachusetts

December 28, 2020