On the machine the collector agent is installed on find the configuration file called IAI.Collector.exe.config located at the default location of;
C:\Program Files\Starling\IARI Collector\
Open the file in Notepad then find the following lines and make the noted changes.
<level value="INFO" />
Change it to
<level value="DEBUG" />
The debug should be written out to the RELOG files. It is a rolling log file and is incremented in the following way.
IAI.Collector.exe.relog, IAI.Collector.exe1.relog, IAI.Collector.exe2.relog
It might be necessary to restart the Starling IARI server. That can be done via windows services and is called.
Starling IARI Collector