I have a digital multimeter(Agilent 34450A) and i want to connect it to matlab with a GPIB cable.I need help, do you have suggestions about it?I want to take data from multimeter to matlab or excel.

 

You will need a GPIB interface card in PC to do this. Or
GPIB to USB......

DIY

https://www.eevblog.com/forum/testgear/gpib-interface-(ieee488)/

Regards, Dana.

 

I would not go the DIY route. The use of GPIB is severely limited with those self-build adapters which essentially are supported by nothing.

Get one of the cheap Agilent/Keysight 82357 GPIB to USB adapter clones from eBay, you can use the Keysight I/O library and tools to make it easy to communicate with your DMM.