如何在9254A中设置保存数据的起点

您没有说明如何生成QPSK信号，或者未生成QPSK信号时生成的信号。
范围不知道它是QPSK。
如果您可以在QPSK序列开始时改变电压的外部信号，或者您的信号在开始时从关闭变为开启，则可以设置触发。
除此之外，这是值得怀疑的。
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安捷伦论坛在“可用”的基础上进行监控，并不一定是解决技术问题的最快方式。



     以下为原文

  You don't say how you are generating the QPSK signal, or what happens on the line when it's not being generated. The scope has no idea it's QPSK. If you can generate at an external signal that changes voltage at the beginning of a QPSK sequence, or your signal goes from off to on at the beginning, then it's possible to set up a trigger. Other than that, it's doubtful.

Al

Disclaimer: For more reliable response, you should consider calling your local Agilent Technical Call Center. The Agilent Forums are monitored on an "as available" basis, and aren't necessarily the fastest way to get technical questions answered.

波形由N8241A生成。
在此波形之前根本没有信号。
Senmeis



     以下为原文

  The waveform is generated by an N8241A. There are no signals at all before this waveform.

Senmeis

如果这是真的，那么您应该能够从“自动”更改为“触发”模式，并将触发电平设置得远离地面，只有在信号打开时才会触发。
尝试使用更简单的信号，如短脉冲，以正确设置。
人



     以下为原文

  If that's true, then you should be able to change to 'Triggered' mode from 'Auto', and set the trigger level far enough away from ground that will only trigger when the signal is turned on. Try it with a simpler signal, like a short burst, to get it set properly.

Al