Fangrui Product Details Scenes To Be Used: At The Performance Site Or During Engineering Debugging, If The Signal Of Some Lamps Is Unstable, Or The Lamps Are Out Of Control Or Unresponsive. You Can Use This Signal Line Tester To Test Signals, Or You Can Test Signal Lines Individually. One End Of The Signal Cable Is Connected To The Signal Output Port Of The Console, And The Other End Is Connected To The Signal Tester. Warm Reminder: During Testing, It Must Be Ensured That The Console Is Connected To The Signal. Testing On Ports Other Than Signal Lines Is Allowed. Each Lighting Console Has A Different Refresh Rate, So Some Testers Will Cause The Led Indicator To Flicker When Testing Signals. (this Situation Does Not Affect The Normal Use Of The Line Measuring Device) Line Measuring Device Fault Prompt: 1. The Blue, Red And Green Indicators Are All On, Which Means The Signal Is Normal. 2. A Single Green Indicator Light Lights Up, Indicating That The Ground Wire Is Disconnected Or Short-circuited. 3. A Single Blue Indicator