Denso BHT-700QWB-CE, User Manual

Page: 136 / 182

118
BHT-700QWB-CE/700QWBG-CE
5.3 Bluetooth
®
Communication
5.3.1 Notes for Bluetooth
®
Operations
The BHT supports Bluetooth
®
wireless data transmission.
•
If there are too many communications errors, first make sure that the BHT points directly at other
Bluetooth
®
-enabled devices because the 2.4 GHz band requires a more or less straight line path.
Note also that the low-power radio waves have trouble passing through human bodies and other
obstacles along that path.
•
In the vicinity of wireless LAN devices using radio waves in the 2.4 GHz band, Bluetooth
®
link operation
may cause interference to radio communications, resulting in decreased communications speed or
communications failures.
•
The Bluetooth
®
link will not operate properly in the vicinity of microwave ovens, industrial heaters,
high-frequency medical equipment, and other sources of radio waves in the 2.4 GHz band.
•
Electromagnetic noise from personal computers, refrigerators, and other home appliances can also
interfere with link operation.
•
Environmental factors that can also interfere with link operation include large metallic objects, metallic
dust, or metallic walls in the vicinity of the path and vibration at either end.
−
Point
−
Requests to System Designers
Before developing the application, make sure that the intended environment is free of the
interference factors above and thus actually capable of supporting link operation.
Assume that there will be communications failures requiring robust retry capabilities in the
software.
When introducing the BHT link operation into an environment where equipment using radio waves
in the 2.4 GHz band operates or when introducing such equipment after the introduction of the
BHT link operation, be sure to confirm that the BHT radio link operates properly with all equipment
being in operation beforehand.
If the environment of the radio communications system is changed after the introduction (e.g.,
newly installed household appliances and movement/addition of shelves or objects), then confirm
that the radio link operates properly again before the actual use.