Update BLC_CHANNEL.md

BLC_CHANNEL.md

-
 Integration with blc_loop
 =========================
 
+This is for synchronisation, for more information about blc_channels, see ( https://git.u-cergy.fr/blaar/blibs/blc_channel/blob/master/README.md ). 
+
 output channel
 --------------
 
-Example defining a synchronous (':', '/' for asynchronous) channel of unsigned char ('UIN8') of 4096 values with no specific format ('NDEF').
+Example defining a synchronous (':' double synchronization, '/' for asynchronization) channel of unsigned char ('UIN8') of 4096 values with no specific format ('NDEF').
 
     #include "blc_channel.h"
     #include "blc_program.h"