Time for another mass response! I tried to address everything that other users haven't answered already.
First of all, there's been a new firmware release, 1.0.03. It's not a major one though, it mostly includes emulation mode and some VISA communication fixes that were heavily requested. One notable thing,
the 2700 triggering on pin 6 of the DIO port that Jens01 asked about has been fixed so that the DAQ6510 triggers properly now. The links have the full release notes.
For the DAQ6510:
https://www.tek.com/digital-multimeter/daq6510-software/daq6510-firmware-v1003-and-release-notesFor the DMM6500:
https://www.tek.com/digital-multimeter/dmm6500-software/dmm6500-firmware-v1003-and-release-notesCan you show the graph of the frequency response of the filter? So that I can make decisions about the need for additional filtering?
It became clear about the digitizing V mode.
I can try making a graph next if this doesn't answer your questions but I think I'd have to order some equipment to make a good one. This answer comes from the hardware team:
The filter can be modelled as a simple low pass filter with a time constant of ~ 150ns putting the transition at around 1MHz. Investigate what that means to your signal input being digitized. There are higher poles also between 5MHz and 50Mhz but the upper limit response is dominated by the ~ 1MHz.
Suggestions for best added anti-alias additional filtering to really kill the artifacts. These match up well to the internal ADC. The more poles the better until ~ 8:8 pole BESSEL type low pass filter set at ~ 400kHz – use this if you want to preserve signal waveform fidelity/accuracy (constant group delay, won’t show dispersive effects)
8 Pole MFB or BUTTERWORTH low pass type set at ~ 450kHz – use this for best attenuation, has pass band ripple (can be designed for < 1%), has some dispersion.
NOTE: The suggested pole locations are chosen to support the full input bandwidth of the digitizer for all signals. If that’s actually not needed and you wish to tailor it to your signal, the it is better to place these poles approximately 1 decade higher than your highest signal frequency of interest. This will optimize it for your specific signal achieving the highest input noise attenuation. When implementing your filter, keep resistances < 20k if possible to avoid making additional high frequency noise sources.
Example1: Square wave(PWM etc..) just want to see the signal, – need full BW set to just below 500kHz (400, 450 is as in above suggestions) with appropriate # of poles can use any type. Consider no filter at all if you aren’t looking at low frequencies that could be aliased and you really want highest bandwidth.
Example2: Noisy sinewaves, ramps etc.. and care about amplitude accuracy < 10kHz. Set at ~ 150kHz and use Bessel up to 8 poles.
NOTE: If you design an input filter, keep in mind the DC specifications. The digitizer function is specified for DC performance and if you want to preserve that, you will need to select the right components for your filter.
The hardware was designed to not force an artificial bandwidth limitation so that it can be the most flexible for all applications. Programmable HW filtering options were considered but the team decided to leave them out to make the unit as versatile as possible.
How should I set up the device so that after filling in one buffer, it will without a break begin to fill the next buffer?
I don't think this is possible and I'm not sure why you would want to do this, wouldn't it be better to set one buffer to the maximum size than have 2 half size buffers? Do you want all the data you're taking or are you aggregating it in some way? If you're processing, it might be possible to use a TSP script. If you want all the readings directly, you're limited by the bus speeds.
Brad O.
Thanks for manual, interesting read! We volt-nuts always like to know what more equipment we need to buy for calibrations
I missed it before, because Tek site ain't too much friendly for old-school folk. Clicked DMM6500 -> Manuals -> Service = nothing, so I assumed it's not published yet.
Ah it looks like the web team assigned it as a User manual, I think that's a mistake. I filed a bug report to have them update the classification, I fully understand your confusion. I'm also working with the web team to improve the way tek.com handles documents like these, you're not the only one to have problems finding things.
After a good warmup, I had both, the DMM7510 and the DMM6500 on the same 10V source in parallel.
Both instruments on 5 NPLC, 10 MOhm, AutoZero ON
Why would I get such a jump in the middle of the DMM6500 graph?
That
does look strange and I don't like it. I'll try to reproduce it after the Holidays. Was your source a custom 10V reference? I would expect popcorn noise to have a shorter duration but it's a possibility.
Also interesting (funny):
The DMM6500 counts the x-axis with [h:m:s] and the DMM7500 in [ks]
This was specifically done for the DAQ6510, but I think the change to [h:m:s] is slated to go in the next 7510 firmware too. I think it makes a lot more sense than kiloseconds.
Both graphs for the 7510 and 6500 show a problem with the scaling. There is no way to tel the actual scale. I know this a rather extreme case, but the labeling could get some improvement. Maybe make sure the ticks are not fixed pixel width but something like a 1-2-5-10 sequence in real voltage / current and than somewhere also show the distance. So a little like with scopes.
The firmware team is looking into ways to improve labeling when you have a super stable signal like that. I don't know where they are in that process, but that's on the docket to be addressed.