• RE: Passing Long array using python

    The input buffer is ~2000 characters.  Strings larger than that in a single VISA write will cause the -363, Input Buffer Overun Error.

    Ideally, myList could be computed/generated in the TSP Lua runtime within the 2600B scripting engine.
    But if not possible for your use case, here is one way that a long array in Python can be populated into a table in the TSP side of things.

    # in Python, build an array of values
    record_length = 360   # how many datapoints to generate
    cycles = 3 # how many sine cycles
    length = np.pi * 2 * cycles
    vector = np.sin(np.arange(0, length, length / record_length))
    #send commannds to
    # create an empty table, myList, on the 2600B
    #index through and write them on by one to table variable in the Lua runtime environment
    #Lua uses 1 based index vs. zero based for Python
    #myLuaArray[i+1] = PythonArray[i]
    for i in range(0, record_length):
         my_instr.write("myList[" + str(i+1) + "] = " + str(vector[i]))
    #print out how many elements we have loaded into myList
    print("Number of myList entries: " + my_instr.query("print(table.getn(myList))"))
  • RE: Connecting Force Low to ground on rear terminal

    Sounds like you have a model 2450 SourceMeter.
    You could use a triax shorting plug on the Force LO to connect the center pin to outer shell which is at chassis ground.
    Keithley part number for shorting plug:  CS-1546
    Info about CS-1546 Triax Shorting Plug
  • RE: Continuous measurement with 4200-SCS

    You do have the older 4200-SCS running the KITE software.
    More than 10 years ago, we transitioned to 4200A-SCS and Clarius software.
    Keep in mind, there is always an upgrade path.  Contact your local sales office for more information.

    For repeated execution of an ITM, check out the Reference Manual on enabling the cycle mode.
    I believe max number of cycles is 128.  When running the cycle mode, the ITM test results will have a tab for each cycle.
    This is similar to having multiple append tabs.  But cycle mode relieves you of some button pushing.

    If cycle mode is not enough cycles, you might be able to use the Stress/Measure cycling and just pick a benign stress condition.

    Alternately, you could close the KITE GUI interface and instead use external command interface (KXCI).  And then from another computer you can send commands over GPIB or LAN to do the repeated IV curves and read back the data.
  • RE: Hearing relay and voltage drop between measurements

    Does your SMU1 also have a 4200-PA?

    In your pseudocode, you have a DV2 but no other parameters.  Is SMU2 playing a role in this setup?

    If you run an ITM out of KITE for the voltage sweep on the 80KΩ, any clicking then?

    Sounds like some range selection issues are going on with the clicking.
    Especially if you have the 4200-PA, you could try using the RG command to exclude some of the lowest and most sensitive ranges.
    Without a pre-amp, the 100nA and higher ranges are available from the SMU.
  • RE: How to detect end of list sweep in a python (pyvisa) script?

    If the instrument is busy carrying out the sweep, then the VISA write of the "*OPC?" command is not processed until the sweep completes.  This is why the VISA read will timeout.

    An alternate approach is to use VISA's ReadSTB() to obtain the value of the status byte or status.condition register.

    I put an elaboration and Python sample in the attached document.
  • RE: 2611 SMU (NON A, NON B) Programming Reference

    The PDF is too large for attaching, so here is link to Box:

    Reference Manual for the original 2600 models
  • RE: Issues with Connecting Keithley 2450 to PC due to IP Address Changing

    The LAN communication can be applied from your router (DHCP) or selected manually.

    Sounds like you have been using DHCP and the router is periodically giving new address?

    Perhaps you can reserve an address in the router setup and manually configure the instrument to use it?
  • RE: SMU 2400 Series ErrorCode

    Appendix B-2 in the 2400 Series User Manual has the error codes.
    NOTE:  this is not the touch screen models (2450, etc).

    User Manual for 2400 Series SourceMeter
  • RE: Multiplexing SMU 2450

    Some general comments:

    For switching pA levels, consider the offset current spec of the switch.

    For parallel reliability testing, consider using a power supply to apply voltage bias to N devices.
    And then switch in a sensitive amp meter one by one.
    When not measuring the current, the switching scheme needs to maintain pathway completion for the current to flow.
    Model 3761 switch is one example.
  • RE: Linking two 2450 SMU

    KickStart does not use tsp-link for communication with the SMU.
    KickStart needs a computer connection to each SMU (lan, usb or gpib).

    If you additionally have tsp-link between the instruments, KickStart can use that for their triggering/coordination.