ICP DAS Co., LTD
2
Q1
、
How to increase communication distance of RFU-400?
(2016/12/16, Ming)
Ans.
：
We provide two ways to reference
：
1.
Use RF 650 bps baud rate. In the case of a straight line visual distance, the
communication distance of 650 bps baud rate is up to 2 km.
2.
Use the following diagram architecture
：
Using two RFU-400s, connect their RS-232 or RS-485 to each other, as shown in
the middle of the figure above. So that you can form a group of RFU-400 repeaters to
extend the wireless communication distance.
Q2
、
Why some time RFU-400 would receive the data of others
channel? (2016/12/16, Ming)
Ans.
：
This is because although you use of different channels, but still in each other's
communication bandwidth.
RFU-400 communication bandwidth = 40 k + communication baud rate
Assuming you use a communication rate of 38400 bps, the communication bandwidth is
78.4 kHz, so if the channel spacing is less than 78.4 kHz it is possible to receive data from
each other.
The channel spacing of the RFU-400 in the 429 MHz band is 12.5 kHz, which is
equivalent to an interval of 6 channels. The channel spacing in the 433 MHz band is 100 kHz,
ie, adjacent channels will not be affected.
