how to auto log off wyse xenith on idle?

 how to auto log off wyse xenith on idle?

How can I tell the wyse to log a user off after 20 minutes of idle ? Users keep walking off and leaving the sessions logged in which hogs up the VDI's...

I have tried setting the idle session in the Citrix Console, but it only seems to work with web based connections to citrix using reciever..

The wyse boxes just stay logged in and never time out??

Surely there must be a way?