upsd usually allows a driver to stop responding for up to 15 seconds before declaring the data "stale". If your driver takes a very long time to process updates but is otherwise operational, you can use MAXAGE to make upsd wait longer. Most users should leave this at the default value.

Tell upsd to look for the driver state sockets in path rather than the default that was compiled into the program.

Bind a listening port to the interface specified by its Internet address. This may be useful on hosts with multiple interfaces. You should not rely exclusively on this for security, as it can be subverted on many systems. Listen on TCP port port instead of the default value which was compiled into the code. This overrides any value you may have set with configure --with-port. If you don’t change it with configure or this value, upsd will listen on port 3493 for this interface. Multiple LISTEN addresses may be specified. The default is to bind to 127.0.0.1 if no LISTEN addresses are specified (and ::1 if IPv6 support is compiled in). This parameter will only be read at startup. You’ll need to restart (rather than reload) upsd to apply any changes made here.

This defaults to maximum number allowed on your system. Each UPS, each LISTEN address and each client count as one connection. If the server runs out of connections, it will no longer accept new incoming client connections. Only set this if you know exactly what you’re doing.

When compiled with SSL support, you can enter the certificate file here. The certificates must be in PEM format and must be sorted starting with the subject’s certificate (server certificate), followed by intermediate CA certificates (if applicable_ and the highest level (root) CA. It should end with the server key. See docs/security.txt or the Security chapter of NUT user manual for more information on the SSL support in NUT.