MSO-X 3054A波形显示无效

范围波形何时有效以及导致它们无效的原因是什么？
未开始自动测量时，如何标记无效波形？
在阅读我遇到的捕获波形的问题后，这些问题会更有意义。
使用所有四个模拟通道进行测量。
范围数学能力用于减去两个通道。
数学结果与捕获的其中一个通道匹配。
匹配波形是方波。
范围测量能力用于捕获应匹配的两个波形的TOP和BASE值。
*物理信道（CH4）*的TOP测量结果显示> 15.1V。
>符号表示测量结果可疑，可能无效。
物理通道的电压/ div支持至少50V的TOP值。
15.1V TOP测量与显示的波形相匹配。
数学通道显示TOP值为45.8V。
*因此，物理通道被错误地捕获并显示。*在有效波形和测量（一个没有>）之前，后续捕获导致几次不良捕获（带有>的捕获）。
无需平均即可捕获所有波形。
谢谢你的帮助。
-------------------更新4月30日对于相同的设置，未重新发生范围错误。
我联系安捷伦，总的感觉是通道ADC过载，导致不可预测的行为。
为了测试这个想法，我使用相同的设置通过一个或四个分区驱动通道。
一个分区过载不会导致错误。
四分频过驱动影响过驱动信道但不影响交错信道。
我确认范围不会标记未进行测量时过载的波形。
重新审视原始范围错误，我无法解释ADC饱和度所见的失败。
通道4不会过度过驱动，并且交错通道3是范围界限内的DC电平。
如果我学到新东西，我会再次更新。
现在范围正在发挥作用，我有一个有趣的设计可供使用。编辑：2013年5月1日上午12:14发表于scope_6.txt1.0 KBscope_10.txt1,021字节scope_10.png34.0 KB



     以下为原文

  When are scope waveforms valid and what causes them to be invalid?  How are invalid waveforms flagged when an automatic measurement is not begin made?  These questions will make more sense after reading the problem I encountered capturing waveforms covered below.

Measurements were made using all four analog channels.  The scope math ability was used to subtract two of the channels.  The math result matches one of the channels captured.  The matching waveform is a square wave.  The scope measurement ability was used to capture the TOP and BASE values of the two waveforms that should match.   The TOP measurement result for *the physical channel (CH4)* showed >15.1V.  The > sign indicates the measurement is suspect and may be invalid.  The voltage/div for the physical channel supported a TOP value of at least 50V. The 15.1V TOP measurement matched the waveform displayed.  The math channel showed a TOP value 45.8V.  *Therefore, the physical channel was incorrectly captured and displayed.*  Subsequent captures resulted in several bad captures (ones with >) before a valid waveform and measurement (one without >) were made.   All waveforms were captured without averaging.

Thanks for your help.
------------------- update April 30
A scope error has not reoccurred for the same setup.  I contact Agilent, and the general feeling was that the channel ADC was overdriven which resulted in unpredictable behavior.  To tests this idea, I over drove the channels by one or four divisions using the same setup.  The one division overdrive did not cause errors.  The four division overdrive affected the overdriven channel but not the interleaved channel.   

I verified the scope does not flag waves that are overdriven when a measurement is not made.

Revisiting the original scope error, I cannot explain the failure seen by ADC saturation.  Channel 4 is not excessively overdriven and the interleaved channel 3 is a DC level within the scope bounds.

I will update this again if I learn something new.  Right now the scope is working and I have an interesting design to work on.

Edited by: seen on May 1, 2013 12:14 AM   
附件

• scope_6.png50.8 KB
• scope_6.txt1.0 KB
• scope_10.txt1,021 字节
• scope_10.png34.0 KB