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标题: How to Test Communication Relay with Multimeter: A Step-by-Step Guide Communication relays are essential components in many electrical and electronic systems, particularly in telecommunications and control circuits. They serve as electrically operated switches, allowing signals to pass or be interrupted according to a control voltage applied to their coils. Ensuring that a relay functions correctly is crucial for maintaining system reliability. One of the simplest and most effective ways to test a communication relay is by using a multimeter, a versatile tool capable of measuring voltage, resistance, and continuity. This article will provide a detailed guide on how to test a communication relay with a multimeter safely and accurately.