Please tell me why I can't use WaveformLength command in program that is used to get a data from oscilloscope.

Dear Sir or Madam,

I would like to use WaveformLength command when I get data from an osiclloscope. But, an error has occurred. Error message is 'The feature is not supported for the instrument.'. Mathworks web site says that the command can be used with Tektronix and Keysight instrument.

I'm glad if you tell me it.

Sincerely,