An array for multiple LHS assignment cannot contain expressions

so I am trying to using matlab to control keithley sourcemeter, and I am trying to do a voltage sweep. The function given by the instrument is

[READING]=invoke(OBJ,'performsweepvi',RANGING,SPACING,DIRECTION,SOURCECOMPLIANCE,SOURCEPROTECTION,START,STOP,NUMBEROFPOINTS,SENSERANGE,SPEED,READING)

I put in the necessary value on the right hand side and when I execute it, it responds that An array for multiple LHS assignment cannot contain expressions. So I am not sure what to do. I have removed the bracket and another error shows up where it needs a logical or numerical value.

[Walter Roberson]

The closest I can see to that function name, performsweepvi, has to do with keithley functions for communicating with Labview VI ?

[Jenny]

when I select on the Ke24xx driver. and I select functions, that's the function present to sweep voltage. It's the driver used so Matlab can communicate with the instrument. I've used it to measure the voltage versus time. It's just that now I am trying to do a voltage sweep and for some odd reason, it's not working. Are you suggesting that I should go about another way to sweep the voltage?

[Walter Roberson]

What is the model number of the device you are using?

[Jenny]

it's keithley 2401 sourcemeter

[Walter Roberson]

The Instrument Control Toolbox does not support the Keithley 2400 models.

[Jenny]

That doesn't make sense because I have been collecting data using matlab for a couple of years. The kusb driver that I use was converted to a plugandplay driver so that matlab could control the instrument.

[Jenny]

I used makemid function to convert it to ivi driver into a driver that matlab can use to communicate with the keithley.