DSO6000中的“Trigger Nth Edge”找不到触发器

嗨，我想在DSO6000中使用“Trigger Nth Edge”功能。
触发“1 Edge”时效果很好。
但是，切换到“2 Edge”时，它找不到触发器。
这有什么问题？
有人可以帮帮我吗？
非常感谢！



     以下为原文

  Hi,

I wanted to use the "Trigger Nth Edge" function in DSO6000. When triggering "1 Edge", it works well. However, switching to "2 Edge", it can't find a trigger. What's wrong with this?  
Can anyone help me, please?  
Thanks a lot!