34461A怎么设置同步多个DMM的触发器

您好Bernd，您是正确的，电压，电流和温度测量的内部处理可能会导致测量值在达到样本计数结束时相互漂移（变得不同步）。
为了最大限度地减少不同功能之间测量时间的变化，您可以尝试使用固定范围关闭显示器，如果打开自动调零（伏特，欧姆），请将其关闭。
如您所知，触发延迟是在接收触发器和样本计数中的* first *读数之间。
没有办法设置延迟来调整个人读数。



     以下为原文

  Hi Bernd,

You are correct that internal processing of voltage, current, and temperature measurements may cause the measurements to drift (become unsynchronized) from each other as the ends of the sample counts are reached. To minimize the variation in measurement time between different functions you can try turning off the display, using fixed ranges, and if auto-zero is on (volts, ohms), turn it off.

The trigger delay as you know is between the receipt of the trigger and the *first* reading in the sample count. There is no way to set a delay to pace individual readings.

嗨jdwindrvr，谢谢你的回复。
我会尝试这个，也许会有更少的差异。
我发现的另一个选择是通过硬件将DMM相互连接。
一个DMM作为主设备从其“VM Comp”BNC输出到所有其他DMM作为其“Ext Trigger”BNC输入的从设备。
当然，您必须仅将一个DMM触发器从Labview配置到主DMM，并将所有从站配置为外部触发器Input。
这样，所有数字万用表都会在很长一段时间内保持同步，但如果您查看一个单一的触发/测量，则会产生很小的时间差，因为“VM comp”输出在执行测量后切换，因此主设备与从设备不同。
此致，Bernd



     以下为原文

  Hi jdwindrvr ,


thanks for your reply. I will try this and maybe there will be fewer differences.

Another option I found is to connect the DMMs with each other by hardware. One DMM as master from its "VM Comp" BNC output to all other DMMs as slaves to their "Ext Trigger" BNC inputs.

Of course you must configure only one DMM trigger from Labview to the master DMM and configure all slaves to the external trigger Input. 

This way all DMMs are in sync over a long time, but if you look on one single trigger/measurement there is a Little time difference because the "VM comp" Output is toggled AFTER a measurent is taken, so master differs from slaves.

Regards,
Bernd

对于相对较慢的DAQ（等于或低于约1 Hz），我在Wifi网桥（Linksys WES610N 4端口双频N娱乐桥）上远程运行了多个34410A，34461A。
（LabVIEW 2014）每次围绕LabVIEW vi main while循环，我都会通过错误线路径和序列结构强制按顺序排列每个DMM的级联软件触发器（每个DMM一个，每个都可以是vi）。
只有在离开级联软件触发器（一个非常快的序列）后，我才读取每个DMM。
数据记录是通过将每个值添加到一个数组（将每个值绘制成图形与时间）以及按每个DMM数据循环对其波形线使用自己的移位寄存器进行排序来执行的。
每次围绕while循环，我使用波形到波形组件（双数组）和构建数组将新值添加到每个波形记录中，以将每个新值添加到双数组中。
在构建阵列之外，最新的阵列进入波形图，然后返回到移位寄存器的构建波形函数。
在每个循环内部，每个新的DMM值都会沿着新行写入数据记录记录的.txt文件中。
每次在每个软件触发之前，我都会运行四个vi，不确定是否有必要。
触发配置，配置多点，然后启动测量，并发送软件触发。
只用两次启动测量一次设置触发器，并在循环周围发送软件触发器似乎不起作用。
您似乎已经在每次启动测量之前发送了一些内容并发送软件触发器。
要在一秒钟的循环中运行两个34410A和一个34461A，我使用额外的732毫秒循环延迟（只是浪费时间延迟来设置我的数据记录速率大约一秒，也许+/-大约5毫秒，剩下的部分
运行整个循环所需的一秒，包括触发，测量，读取，图形和写入，精度为5 1/2位。（对于长光圈，比如100 plc（1.667s），1秒循环当然是，
不可能。我想通过在268 ms内完成循环，然后在时钟上等待一段时间，可能会有更准确的时序。因为每次DMM都是在每次循环的快速序列中触发的，所以没有同步漂移。
可能软件触发并行更快，不确定。（它只是序列序列中的ms，但我还没有定时传播）。另外，OP提到想要关闭LabView计算机，所以相反，这种方法
当然需要LV电脑运行。



     以下为原文

  For relatively slow DAQ (at or below about 1 Hz) I have been running several 34410A, 34461A remotely on a Wifi bridge (Linksys WES610N 4-Port Dual-Band N Entertainment Bridge).   (LabVIEW 2014)

Each time around the LabVIEW vi main while loop, I have a cascade of software triggers for each DMM forced into order by the error wire path and sequence structures (one per DMM, could each be a vi too).

Only after leaving the cascade of software triggers (a very fast sequence), I read each DMM.  The data logging is performed by adding each value to an array (plotting each one to a graph vs. time) and sequencing by each DMM data loop using it's own shift register for its waveform wire.  Each time around the while loop, I add the new value to each waveform record using waveform to waveform component (the double array) and build array to add each new value into the double array.  Out of the build array, the latest array goes to the waveform graph, then back into a build waveform function to the shift register.

Inside each loop, each new DMM value gets written along a new line into a .txt file for the data logging record.

Each time before  each software trigger, I run through four vi, not sure if this is necessary.  trigger configure, configure multipoint, then initiate measurement, and send software trigger.  A one time set up of the trigger with just the two initiate measurement, and send software trigger around the loop does not appear to work.  It seems you have send something before each initiate measurement and send software trigger.

To run two 34410A and one 34461A in a one second loop, I use an additional loop delay of 732 ms (just a wasted time delay to set my data logging rate of about one second, perhaps +/- about 5 ms, the remaining part of a second what it takes to run the entire loop including trigger, measure, read, graph, and write with 5 1/2 digit precision.  (for long apertures, say 100 plc (1.667s), 1 second loops are of course, not possible.

I suppose more accurate timing might be had by finishing the loop in the 268 ms, then waiting for a time on the clock.

Because each DMM is triggered in fast sequence each time around the loop, there is no synchronization drift.  It might be possible to software trigger faster in parallel, not sure.  (It is only ms in series sequence, but I have not timed the spread).

Also, the OP mentioned wanting to turn the LabView computer off, so in contrast, this approach of course needs the LV computer to be running.