Andrea C

As for the manual section I referenced, I see it is gone from what is presently posted on tek.com for the 6485.
I have some older revisions on my computer.

I'll upload the relevant pages for the topic of how the source R and C of the DUT interacts with the picoamp meter (or electrometer) current measure functionality.

Is likely to be due to the different capacitance of your photodiode if at 0V vs some reverse bias.
The DUT C will be larger at 0V.

In 6485 Instruction Manual, look at section noise and source impedance in Appendix I.
It gives a nice treatment of the topic in how the R and C of the DUT interacts with picoammeter gain.
If it is too much C, adding some additional series R can mitigate in some cases.  Just need to account for the I*R drop on the added R.

What sort of cable do you use?  How long?  It too is contributing some C.

Hi Jan,
I wanted to let you know I did duplicate the stalled scan once.  But is very intermittent.
I have opened a bug report for it in our quality system.

For the csv files it does generate, if you compute the delta on the reported time of each scan, does it increase from the expected 2 seconds as the file accumulates rows?

Andrea

Is it just the touch aspect, or no display activity at all?
If Windows is corrupted and cannot run, you could try a system restore.
During boot, press F11 when you see the message about Acronis True Image.
The as-shipped factory image is there.
NOTE:  this will wipe away your existing content in projects or custom user libraries.

You may need to contact your closest office/service center.

We will need to dig into this one a bit.

Question:  if not logging to USB, would the long duration scan operate without any issue?  Do you have opinion about that?

Hello,

The present firmware release level is 1.7.12.
In general, especially if at beginning of a development effort, I recommend to use latest firmware.
However, the issue you are facing will not yet be resolved with firmware update.

For active devices with open circuit voltage greater than 20V, we presently have an issue that is preventing pulsing back to the bias condition of 0A at V_Limit greater than 20.  For now, need to stay within the 1Amp if VOC greater than 20V.

Andrea

Hello Maia,
Factory took a look using a 6517B at A14 firmware, same as you.
Not able to duplicate any issue related to auto range as the applied V to resistor changes.
Factor suggested that your specific unit may have a service issue (RMA).
Andrea

It seems like a surprising amount of settling time for only 1KOhm of resistance.
Any idea of how much capacitance is in your setup?  How long are cables, etc.

Your Word doc shows 5msec is too fast/not settled.  But next delay time is 500msec and 1000 msec which show good agreement in the IV curve for the 1K resistor.
Did you try anything smaller than 500msec?

Just as troubleshooting technique, under manual operation, you can configure the DAQ for digitize current mode and even use edge triggering.  With that you can perhaps capture the actual settling time for steady state when the power supply changes from V1 to V2.

What value of current limit to are you using with the power supply?  If set too low, perhaps that is being invoked during the voltage change when currents will be largest.  If yes, this will slow down the final value steady state time requirement.

 

Sorry the manual is a bit sparse on it.

The values are adjustable because some applications need different values.
For example, if using the load to discharge batteries to generate battery models, it will be common to avoid discharging the battery beyond its lowest voltage.  A 18650 battery is 3.7V nominally, but stop discharging at ~3.0V.
By using these values the load, you can automatically stay within bounds.

If not already, go to tek.com and get the User Manual for the 2700.  There are SCPI commands illustrated in such as section 7 on scanning.

Also our older forum may have some good posts:
https://forum.tek.com/viewtopic.php?f=62&t=142711
OR
https://forum.tek.com/viewforum.php?f=62