Carousel 7 is designed to fully manage all BrightSign OS updates. When you connect a BrightSign Player to a Carousel 7 Server it will install the OS version we’ve tested with the Carousel version. We do not support installing or using any other version of BrightSign Firmware.
You can view our Firmware/OS Version table here: https://c7-support.carouselsignage.com/hc/en-us/articles/360051304452-BrightSign-Firmware-and-OS-Supported-Models-by-Carousel-Version