Ty McKinney

Hello,
You are doing everything right as far as I can tell from what you are doing. ~3ms is the time it takes for the relays on your physical scan card itself to open/close the relays. That, paired with operating overhead such as firmware and other settings will add additional time to the actual time for a scan. The quickest scan possible with the 7700 card is expected to be around that 10ms mark you are hitting. See the video below for a good walkthrough on how to set up your DAQ6510 for the quickest scan possible, as there may be a few tips and tricks you could add in for your setup.

https://www.youtube.com/watch?v=2d0RFuENBvo

Hello,
See page 7-34 in the reference manual attached below as this should give you a good idea on what you are wanting to accomplish.
Model 2651A High Power System SourceMeter Instrument Reference Manual | Tektronix
Also, I saw you set your source range to 10 but the last value in your lsit is 19. If the lsit does not autorange for you, this may cause some issues as you're attempting to source a value well outside of your set range of 10.

Hello Dave,
Are you operating via front panel or remotely and sending commands? If remote, which command set are you using (TSP or SCPI)?
If using remote communication, you may need to add some display commands to specify what you want displayed on the front panel during data acquisition.

Hello,
Apologies, but we do not have that model generated. If you create a case with our technical support team we can discuss some options, if you are interested.
Here is the link to create a case with us: Contact Tektronix Technical Support | Tektronix

Hello,
Can you create a case with our Technical Support Center? One of our Application Engineers will work with you one on one to help you find a solution. When you create the case, please add the link to this forum post for a reference. 
Thanks!
Contact Tektronix Technical Support | Tektronix

Hello,
We have an available connector you are looking for. Apologies for late response! See attached PNG.
3720-MTC-378 PIN FEMALE TO MALE D-SUB CABLE ASSY, 3M

Hello Eniola,
The 26XX line of SMU's do not take SCPI commands. We utilize a command set known as TSP (test script processor) which operates in a similar way. I'll link the reference manual below, see page 2-51 and on for sweep functions and there are examples provided as you read along. Specifically, see section 9 for all TSP commands.
Additionally, I would recommend downloading TSB (Test Script Builder) which will allow you to program and run commands remotely. In the navigator pane on the left hand side, you can find examples for a linear IV sweep example which would help you to start building and customizing your setup once you've read the sections I recommended above.

Here is the reference manual: Series 2600B System SourceMeter Instrument Reference Manual | Tektronix

Here is link to download TSB: Keithley Test Script Builder | Tektronix

Hello,
Zero check is a feature that notes the internal voltage offset within the unit. Zero correct allows you to algebraically subtract the internal voltage offset value from your measurement thereby correcting the value of zero within the instrument. Very similar to a REL function, however REL can be used to subtract out ANY level of signal or reading. Zero check/correct is specifically for correcting the value of zero by subtracting internal voltage offsets that would otherwise result in the instrument reading slightly higher than "true" zero.
Zero Check and Zero correct should both be done prior to making a measurement. Zero check willl be disabled to perform a reading.
See the manual I'm attaching below for more info. Ref pages 2-13 and on.
Model 6514 System Electrometer Instruction Manual | Tektronix

Kenneth,
Did the error first show after trying to update firmware or was this before?
What version were you on and which version were you upgrading to?
We have seen some issues when updating from older firmware to newer even though there is no hardware mismatching. I'm afraid this unit may need to be sent in to service for our team to look in to if this error does not go away. I'll attach the service link below just in case:

Use this link if located in the US: Service Quote | Tektronix
Use this link if located OUTSIDE of the US:Request Instrument Repair/Calibration for Tektronix & Keithley Products | Tektronix

Hello,

1. Minimum operating voltage in 4^th Quadrant as sink mode(or load mode)

We have same voltage accuracy in source and sink as the attached table(see png). We have 5 voltage ranges 100mV to 40V. In the minimum range 100mV, we have 5uV programing resolution but +/-(0.02% of reading + 500uV offset) for uncertainty which means that we can set or program 5uV but actual value sources with +/- 500uV uncertainty. This is voltage source mode case (CV mode).
The other case is that we can control output voltage level by compliance voltage in the current source mode. In this case, we have 10mV minimum in compliance voltage programing. I would not recommend the second case for accurate voltage sourcing applications.
 

2. Pulse Condition

Min/Max pulse width/rise time are very wide ranges depending on DUT impedance, source range and measure range. In the voltage source mode, we have usually about 300us ~ 1ms for pulse width. Please check out the datasheet for every individual case.
 

3. Output Off mode

If a DUT is an energy storage device like battery or solar cell, the output off mode must be high-Z mode. The default state of the instrument 2651A is 0V like ground. As soon as lead cables touch the DUT, the instrument should start to discharge the DUT. High-Z mode of output off mode prevents discharging issue in the DUT connection.