Hello Martin,
When @Moxified was trying to use PGM capabilities the 2.0 binding didn’t have the ability to send commands directly to the DSC Alarm system. That option has since been added to the binding using a different method other than ‘actions’. The current binding version, 2.1, has this capability, so I would recommend restarting with version 2.1 and using the binding from there. That way you won’t have to install a separate beta version to get that feature working. Here are some links that may help out:
DSC Alarm Documentation
openHAB 2.1 Announcement
openHAB2.1 Release
P.S.
Just saw @Moxified’s reply. Basically, just repeating what he said.