This is a post as a reference to others on how I resolved my ghosting issues. Well mostly resolved, I still have a 1mV per 1V adjustment. Works fine with my hardware in between. You may want to tweak the values around to get none at all. Feel free to post your values and how you fixed ghosting issues. I only added Crosstalk as a reference in subject for those that are unaware of ghosting.
Same Topic on NI Forums:
My Offline Setup:
Direct connection of a NI PXI-6723 to a NI PXI-6255. I tweaked around with the capacitors, but not so much with the resistors.
Ghosting was resolved having a 100K resistor and 25nF capacitor on each Analog Input Signal to GND.
A dummy channel (in my case I just added an extra AI reads to DAQmx AI) between each Analog Input Signal. These dummy channels were connected to GND using a 100K resistor and 47nF capacitor.
I had to reduce either my rate or the AIConv.Rate proprety node.
My Live setup with the minor hardware in between:
I had to remove the 100K resistor and 25nF capacitor on the Analog Input Signals (This caused too much voltage drop on the system).
Everything else remained. No ghosting at all.
How Do I Eliminate Ghosting from My Measurements?
M Series User Manual (Chapter 4)
I am trying to get my Keithley3706A up and running with LabVIEW but there are still some problems I am facing.
I want to measure x channels with usage of filter.
So I want to measure each channel x times and filter the results.
I have found some functions like:
dmm.filter.enable = True
dmm.filter.count = 100
dmm.filter.type = dmm.FILTER_REPEAT_AVG
but it seems it still wont work.
I am using the vi's Keithley itself provides on their homepage.
Another problem I have is that I cant get more than 9 values into my buffer, for example if i want to create a scanlist with 1001:1010 I only get one value. If i create my scanlist with 1001:1009 it works just fine.
I could not find any reference to this problem by now.
thanks in advance
The 34401A is not longer available in Canada. We need to change and use the 34461A as a replacement and we are having trouble with the peak-to-peak measurements (We are using LabVIEW).
We use the peak-to-peak option while reading a communication line in order to get the min and max values. The code:
This code no longer works with the 34461A. Reading the AC will only give the RMS values. We dont really care how to get the min-max of the communication channel, as long as it is in a respectable time (10s at most...). Reading the signal with DC is not fast enough. The communication signal is Â±100mv. We verify the min-max range to be around 200mV.