Remote interfacing with Agilent 34401A multimeter

Discussion in 'General Electronics Chat' started by MrBuggy, Mar 15, 2014.

  1. MrBuggy

    Thread Starter New Member

    Nov 7, 2013
    Hello forum,

    I have a project right now that requires me to continuously read data from a multimeter. To do this I have to remotely interface with this Agilent multimeter.

    Page 192 of the manual shows a sample program "RS-232 Operation Using QuickBasic". I installed quickbasic from this website:, copy pasted the code and nothing works. I do know that I have to edit the code to the correct port, baud settings etc.

    I just really want hints from people on how to set this all up (Do I need to install more programs or drivers other than quick basic? I imagine that quickbasic alone cannot access my usb ports)as the manual and google hasn't helped me.

    From the manual I was able to set the multimeter to RS 232, 300 Baud, no parity, and SCPI language (and this is what I want).

    Other notes:
    I have a USB to Serial

    The manual is attached.

  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    A lot of old software needs a real serial port and does not recognize usb at all.
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    QuickBasic? Do you have a version that works under your version of Windows?

    It's really obsolete now, it's a DOS program. Visual Basic is the replacement, with VB Express being a freebie download.

    See if your windows still had Hyperterminal, that alone should be able to talk to the instrument over the serial port.

    If you don't have that google it's replacement, several free programs out there, some very good ones too.
  4. MrBuggy

    Thread Starter New Member

    Nov 7, 2013
    Yes I have a version that works on my laptop. I could even run sample programs from Wikipedia's QuickBasic page.

    Also, I forgot to note that I have the driver installed for the USB to serial.
  5. crutschow


    Mar 14, 2008
    What type of USB to serial adapter are you using?
  6. MrBuggy

    Thread Starter New Member

    Nov 7, 2013
    I am using a prolific USB to serial
  7. ifixit

    Distinguished Member

    Nov 20, 2008
    Can you post the documentation that came with the driver? It should explain how it works.

    QB likely only knows how to open a COM port. So the driver has to look like a COM port to QB (or replace the windows COM port driver) but then drive the USB port with the data from the QB program. Your converter will the convert USB to RS232 and back again.

    TEST: You can loop-back the data by connecting TX to RX at the RS232 connector. Now write a program to see if what you sent comes back into the receive buffer. This verifies the link is working up to where the DMM plugs in.

    Have Fun,