Canon Wireless Transmitter WFT-E6A - Manual (Page 89)

89
Synchronizing the
Camera Time Wirelessly
The time on EOS-1D X cameras can be synchronized over a wired LAN
connection. Also you can wirelessly synchronize multiple EOS-1D X
cameras when WFT-E6 units are attached.
Set the master camera time on up to 10 slave cameras, as needed. Note
that even after synchronization, there will be a slight margin of error
between master and slave camera time of ±0.05 seconds, at most.
Slave camera
Master camera
COP
Y