RF-BM-ND08
Shenzhen RF-star Technology Co., Ltd.
Page 15 of 19
The module has two antenna output modes, which are on-board PCB antenna and stamp half-hole output (ANT pin,
see pin function table for details).
The default delivery is the onboard PCB antenna, L1 position (1NH) is welded. If you want to change to a half-hole
antenna output, disconnect the L1 position capacitor. The location of L1 is shown in the figure below.
Figure 8. Antenna Output Mode Change
4.5 Trouble Shooting
4.5.1 Unsatisfactory Transmission Distance
1.
When there is a linear communication obstacle, the communication distance will be correspondingly weakened.
Temperature, humidity, and co-channel interference will lead to an increase in communication packet loss rate. The
performances of ground absorption and reflection of radio waves will be poor, when the module is tested close to
the ground.
2.
Seawater has a strong ability to absorb radio waves, so the test results by seaside are poor.
3.
The signal attenuation will be very obvious, if there is a metal near the antenna or the module is placed inside of the
metal shell.
4.
The incorrect power register set or the high data rate in an open air may shorten the communication distance. The
higher the data rate, the closer the distance.
5.
The low voltage of the power supply is lower than the recommended value at ambient temperature, and the lower
the voltage, the smaller the power is.
6.
The unmatchable antennas and module or the poor quality of antenna will affect the communication distance.
4.5.2 Vulnerable Module
1.
Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure the stable power supply and no frequently fluctuated
voltage.
2.
Please ensure the anti-static installation and the electrostatic sensitivity of high-frequency devices.
3.
Due to some humidity sensitive components, please ensure the suitable humidity during installation and application.
If there is no special demand, it is not recommended to use at too high or too low temperature.
