A testing device (10), an infusion pump or another medical device function testing method, to an anesthesia apparatus or respirator (AB) and to a computer program product are provided for testing the function of an infusion pump (G). The testing device (10) is preferably implemented on the anesthesia apparatus or respirator (AB) and comprises a memory (MEM), a test module (T) and a controller (C). The test module (T) sends a test command (20) to the infusion pump (FG), which sends a response (30) back to the controller (C) after execution of the command. The control (C) can then compare the response (30) received with a reference response (30′) for agreement in order to send a successful function test result.