[Nut-upsdev] Reading UPS variables on Windows without TCP/upsd (direct Named Pipe / local-only access?

[Kantor, Werner]

Hello NUT developers,

I'm using NUT 2.8.4 (Windows snapshot, mingw64) with an Eaton 5SC UPS. The driver is started as:
usbhid-ups.exe -a eaton5sc
and it reports: Listening on named pipe \\.\pipe\usbhid-ups-eaton5sc
At the moment I can reliably read values by running upsd bound to localhost (127.0.0.1:3493) and then querying with upsc eaton5sc at 127.0.0.1. However, due to security/policy requirements we would like to avoid any TCP interface entirely (even if it's localhost-only) and instead read the data strictly locally.
Could you please advise on the following:

  1.  On Windows, is there an officially supported way to query UPS variables without running upsd, e.g., by talking directly to the driver state via the named pipe?
  2.  Is the protocol behind \\.\pipe\usbhid-ups-<upsname> documented and considered stable enough for a custom client (e.g., for exporting to JSON / monitoring)? If yes, where can I find the specification?
  3.  Is there a recommended non-TCP "local-only" transport or mode for clients (named pipe / Unix-socket equivalent) that is supported by NUT tools?
  4.  In my build, upsc.exe does not accept -D/-DD debug options (it reports "unknown option -D"). Is there another way to debug or trace the client request/response protocol?
Our goal is a local readout (e.g., for Zabbix/monitoring) without exposing any network socket. Any guidance on best practices, existing tooling, or build/config options would be greatly appreciated.

Best regards,
Werner

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/nut-upsdev/attachments/20260324/b7f09e5e/attachment.htm>