GC-100-06, GC100-12, GC100-18 have multiple ports, each of which can be set for different functions. By default they are set as IR outputs. But they may also be set as a sensor, IR blaster (GC-BL2), or other custom settings. When a blaster is used, make sure the port is set for GC-BL2 blaster. (Only the Global Cache blaster is compatible).
First, use iHelp.exe to find the GC100 device, or type the IP address in to your browser if you already know it.
Then click on the IR/Sensor link.
Lastly, find the 'connector' you will be using and select the correct function using the drop down box, then click APPLY.
See attachment showing the IR/Sensor page.