Well it depends. You can use RTVCFGSRC to get the info you are looking for but it may not really tell you what you are looking for.
You should check out this, (Get the correct version for your OS but not much changes,) iSeries work management guide
Director of Information Services
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Graves, Chuck
Sent: Monday, October 19, 2015 10:02 AM
Subject: Device Description Values
Is there a way in CL, to retrieve the OUTQ value for a Display device? I need to programmatically change this value for lots of workstation device descriptions based on current values in the OUTQ parameter.