Disable user inactivity timeout

SOLVED

I've set the idle timeout in IIS on the App Pool to be 0 and for good measure I've set the time out action to be suspend. I've set the recycling so it is off. In CRM, under the administration -> users -> user configuration, the idle timeout is set to 240. If I want to disable the timeout in CRM, does setting it to 0 do that? I'm sure it does, but the help file doesn't say. All it says is this:

The inactivity period (in minutes) after which a user is automatically logged out of Sage CRM.

Sage CRM uses the value in this field only if it is less than the value in Idle Time-out (minutes) specified for the Sage CRM application pool in Microsoft Web Server (IIS). The default idle time-out value set for the Sage CRM application pool is 120 minutes.

The help file doesn't say how to disable the timeout. Also, I assume that setting the value in CRM to a value higher than the app pool timeout will be pointless as the app pool will suspend or kill the process anyway?

A common question I get asked is how to stop CRM booting you out after a period of inactivity. IE stop it completely. Anyone? This is CRM 2020.