From the DetectIT Master menu, take option 65 for the Technical Assistance Information (or option 60 from the older style menus).
Alternatively run the following command
For support purposes, your DetectIT Technical Engineer may need to know the latest PTF level of DetectIT.
From the same program ('Technical Assistance Information') press F10; this will show you which PTFs have been applied to your system. The latest PTF is displayed last.