CUE Sender and Receiver via WiFi or Bluetooth.
By changing the group ID, it is possible to operate several groups to prevent cross-talk.
On Master-unit mode, auto-connect to Slave-units near the Master-unit.
Either you may launch Master/Slave first.
You can connect some Slave-units.
CUE signal from the Master-unit will be delivered to the all Slave-units.
Back-CUE signal from any Slave-unit will be delivered only to the Master-unit.
By reason radio wave condition or others, there is a risk of a slight time lag occurs in the signal.