34401A 6 1/2 DMM this nowadays has the status discontinued (since 2016) and currently has status: Supported ( With a date 2022 ).
Originally 34401A this is HP product, and become Agilent product after HP acquisition (back in time).
Very old 34401A these does not have serial port.
Serial port added at some point near to date of HP acquisition by Agilent, then Agilent continued production as is for some time, then they changed product design by removing serial port and by adding USB and LAN.
Unfortunately 34401A with USB has broken compatibility with Windows XP, because Agilent/Keysight does not offer compatible data-logger software.
This topic is for HP / Agilent 34401A nor the first production and neither latest production. By assuming that you do use Windows 7 or higher, then you can use BenchVue even so first issue whom some one will have to deal with, this is getting one USB to RS232 Adapter.
34401A RS232 port this require Null-modem cable.
Therefore please consider a sandwich of USB to RS232 Adapter this be the bread and a Null-modem cable this to be the cheese.
Regarding windows XP compatibility, BenchVue software this does non accept to be installed at XP Pro sp3.
After a long wait for download of BenchVue 2017.exe , I got an error message : Components missing from the operating system OR download file become corrupted.
This post was added as
Be-aware note: And this has mostly to do with the expectation that you might have by thinking to get a Used 34401A and enjoy BenchVue with it, by simply installing this software.
Personally I own several paid software packages ( worth of 4000 Euro) , all Windows XP compatible, and I am not planing to upgrade my OS.
Now your alternative data-logging software it can be PC logging to Excel with IntuiLink
https://www.ittsb.eu/forum/index.php?topic=1485.0