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N9000A系列当EMI平均检测时,离散扫描速度很慢

您好,我有一个与X系列信号分析仪发行说明中的​​注释有关的问题。
这些A.08.03版本的发行说明包含:已解决的问题:N / W6141A,EMI测量应用当使用EMI平均值检测器时,离散扫描速度慢我现在的问题是:1)什么是“离散扫描”?
2)您是否有关于此已解决问题的更多信息?
3)如何观察到这个问题存在?
我的问题的原因是:在过去(对于较旧的固件版本),我检测到使用“EMI平均”迹线的扫描频谱分析仪非常慢(每个频率点步骤至少1秒)。
是否解决了这个问题,我发现了这个问题的解决方案?
先谢谢你,约翰

以上来自于谷歌翻译


     以下为原文

  Hello,

I have a question related to a remark in the release notes of the X-Series Signal Analyzers. These Release notes for the A.08.03 release contain:

Issues Resolved:
N/W6141A, EMI Measurement Application
  Slow for discrete scan when EMI Average detector is used

The questions I currently have are:
1) What is 'a discrete scan'?
2) Do you have some more information regarding this resolved issue?  
3) How can it be observed that this problem is present?  

The reason for my questions is:
In the past (for an older firmware version) I have detected that Swept Spectrum Analyzer using an 'EMI Average' trace was very slow (at least 1 second for each frequency point step).  
Is the mentoined resolved issue a solution for this problem that I have detected?

Thanks in advance,
John  

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李健

2019-7-9 16:18:10
嗨约翰,发行说明在这种情况下不太清楚,我不确定它指的是什么问题。
但是,离散扫描是阶梯扫描,而平滑是扫描扫描。
Discreet扫描允许用户使用比平滑扫描更​​宽的跨距扫描EMI探测器,因为它必须遵守仪器扫描时间规则。
话虽如此,CXA中使用的W6141A EMI接收器测量特性无法使用离散扫描类型,只有与X系列其余部分一起使用的N6141A具有此功能。
实际上,CXA中的架构限制不允许这样做。
我们所有的旧仪器都使用扫描扫描(我们现在称之为平滑扫描)。
使用这些新仪器添加了离散扫描。
但是,每当您尝试使用EMI探测器扫描或步进时,它将比仅使用峰值检测器的情况慢得多。
这是由于EMI探测器的指定充电和放电时间。
由于我们所有新推出的4 ks接收器的最大扫描扫描时间有限,因此在大跨度范围内使用EMI检测器时可以轻松实现这一点。
如果您曾经看过扫描时间达到4 ks,您可能也会收到Meas Uncal消息,因为仪器达到了最大值,但仍不足以使测量正确。
这是我们建议您使用峰值检测器进行所有扫描,然后仅使用EMI检测器测量问题信号的另一个原因。
由于离散扫描不必遵循扫描扫描时间限制,如果您确实认为必须使用EMI检测器扫描,我们建议使用此扫描类型。
这里唯一的限制是4 Ms,但您也可以将每个步骤的停留时间设置为任何可用的,而不会收到Meas Uncal消息。
这样做是因为某些排放标准需要特定的停留时间。
我希望这有助于......最好的问候,迈克

以上来自于谷歌翻译


     以下为原文

  Hi John,

The release notes aren't too clear in this case, I'm not exactly sure what issue it's referring to. However, Discrete scan is a stepped scan and Smooth is a swept scan. The Discreet scan allows the user to scan with the EMI detectors in much wider spans than the Smooth scan will, as it has to abide by the instrument sweeptime rules. That being said, the W6141A EMI Receiver measurement personality used in the CXA does not have the ability to use the Discrete scan type, only the N6141A used with the rest of the X-Series has this functionality. There is actually an architectural limitation in the CXA that does not allow this.

All of our older instruments used a swept scan (what we now refer to as a Smooth scan). The Discrete scan was added with these newer instruments. However, any time you try to sweep or step with an EMI detector it is going to be much slower than if you were doing so with just the peak detector. This is due to the specified charge and discharge times of the EMI detectors. With the limitation of the maximum swept scan time in all of our newer receivers of 4 ks you can easily reach this when using an EMI detector over a wide span. If you have ever seen the scan time go to 4 ks you are probably also getting the Meas Uncal message as well because the instrument reached its maximum and it still wasn't enough to make the measurement properly. This is another reason why we recommend taking all of your scans with the peak detector and then only using the EMI detectors to measure your problem signals.

Since the Discrete scan does not have to live by the swept scan time limitations we recommend this scan type if you really feel you must scan with an EMI detector. The only limitation here is that of 4 Ms, but you can also set the dwell time for each step to anything available without getting a Meas Uncal message. This is done because some emissions standards require specific dwell times.

I hope that this helps...

Best regards,
Mike
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何秀珍

2019-7-9 16:25:47
引用: cmh23 发表于 2019-7-9 16:18
嗨约翰,发行说明在这种情况下不太清楚,我不确定它指的是什么问题。
但是,离散扫描是阶梯扫描,而平滑是扫描扫描。
Discreet扫描允许用户使用比平滑扫描更​​宽的跨距扫描EMI探测器,因为它必须遵守仪器扫描时间规则。

你好迈克,谢谢你的解释。
它澄清了我的很多问题。
我担心我检测到的问题(慢速均衡跟踪测量)是频谱分析仪的固有行为。
您可能知道,我目前无法访问N9000A系列设备,因此我很难确定缓慢的测量时间是否有问题。
但是我要求我们的一位客户调查此问题。
谢谢,最诚挚的问候,约翰

以上来自于谷歌翻译


     以下为原文

  Hello Mike,

Thanks for your explanation. It clarifies a lot of my questions. 
I'm afraid that the problem I detected (slow emi average trace measurement) an intrinsic behaviour of the spectrum analyzer is.
As you probably know, I currently do not have access to a N9000A-series device, so it is difficult for me to determine if the slow measurement time is a problem. However I asked one of our customers to investigate the issue.

Thanks, and with best regards,
John
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