upsrw -s variable [-u username] [-p password] ups
upsrw allows you to view and change the read/write variables inside your UPS. It sends commands via the server upsd(8) to your driver, which configures the hardware for you.
The list of variables that allow you to change their values is based on the capabilities of your UPS equipment. Not all models support this feature. Typically, cheaper hardware does not support any of them. Run upsrw with a UPS identifier to see what will work for you.
Without this argument, upsrw will just display the list of the variables and their possible values.
Some variables are strings, and can be set to any value within the length limit. Others are enumerated types and can only be set to one of those values. Refer to the list to know what's available in your hardware.
If you run this program inside a shell script or similar to set variables, you will need to specify all of the information on the command line. This means using -s VAR=VALUE, -u and -p. Otherwise it will put up a prompt and your program will hang.
This is not necessary when displaying the list, as the username and password are not required for read-only mode.
upsrw can't set variables on your UPS unless you provide a valid username and password. If you get "access denied" errors, make sure that your upsd.users(5) has an entry for you, and that the username you are using has permissions to SET variables.
This program used to be called upsct2, which was ambiguous and confusing.
The NUT (Network UPS Tools) home page: http://www.networkupstools.org/