Can't get my 600Ex-Rt to sync with my 6D, help?

[dbseeker]

Just purchased my 600ex-rt and love it, but I can't seem to sync it with my 6D as a stand-alone slave. My camera options under [External Speedlite Control] called [Flash function settings] or [Flash C.Fn settings] keeps saying "This menu cannot be displayed. Incompatible flash or flash's power is turned off." My camera WiFi is turned on. I have the flash on ETTL (slave) mode. They both are displaying the entanna as on, but when I fire off my camera the flash doesn't fire off. Anyone help me here?

[TCampbell]

The camera has a menu referring to "external speedlite control" because it does not have a built-in pop-up flash.  It's a convenience feature of the new Canon's so that you can control virtually any function of the flash by using on-camera menus rather than having to use the menus on the flash itself.

However... if you detach the flash from the hot-shoe and want to use it remotely, you must have a speedlite controller or another speedlite that has a built-in controller.

For a 600EX-RT you can either use the ST-E3-RT controller -or- you can use another 600EX-RT to control a remote 600EX-RT via radio.  It can also be controlled via optical communication using an ST-E2 or a 580EX II flash.

The 6D does not have a built-in optical controller or radio controller. 

[dbseeker]

TCampbell, thank you so much. I did get the answer after calling Canon. You are on the money. Thank you for responding!