In the past, sending information between the devices must have a wired signal transmission, thus causing difficulties in terms of the late yong to move a device to another location in the temple.
In the past, the data transmission between devices. Required to send data over cable, thus causing difficulties in terms of the oscillation between the lines. And moving the equipment to measure in other places.
In the past to send data between devices. Must have a data transmission through the cable can cause difficulties in the fields of cancer cables between. And moving device to measure in another place.