Ebyte E28-2G4T27SX User Manual page 14

Chengdu Ebyte Electronic Technology Co.,Ltd.
4 CHAN
5 OPTION
Copyright ©2012–2020, Chengdu Ebyte Electronic Technology Co., Ltd.
Communication Channel
Normal mode: When air data rate is 1k, 5k or 10k, the formula to
calculate channel is: 2400 + CHAN * 1MHz; when air data rate is
50k or 100k, the formula to calculate channel is: 2400 + CHAN *
2MHz; when air data rate is 1M, the formula to calculate channel
is: 2400 + CHAN * 3MHz; when air data rate is 2M, the formula
to calculate channel is: 2400 + CHAN * 5MHz;
Continuous transmission mode: When baud rate is 1200, 9600 or
9200, the formula to calculate channel is: 2400 + CHAN *2MHz；
when baud rate is 4800, 57600, 115200, the formula to calculate
channel is: 2400 + CHAN *4MHz; when baud rate is 460800,
921600, the formula to calculate channel is: 2400 + CHAN
*5MHz.
Fixed transmission enabling bit (similar to Modbus)
7
0 Transparent transmission mode
Fixed transmission mode
1
6
5
4 Measuring mode device type (reserved)
0
1
3
Turn off LBT (default)
0
1
2
1 TXD, AUX push-pull output, RXD pull-up input
TXD, AUX open-circuit output, RXD open-circuit
0
input
Transmission power (approximated)
1 0
0 0
0 1
1 0
1 1
Reserved
Reserved
Slave (default)
Master
LBT switch
Turn on LBT
IO driving mode
27dBm（defult））
23dBm
20dBm
17dBm
E28-2G4T27SX User Manual
Default: 0x18
Under fixed transmission mode, the first
three bytes of each user's data frame can be
used as high/low address and channel. The
module changes its address and channel
when transmit. And it will revert to original
setting after complete the process.
It is transparent transmission under
continuous mode.
Under range measuring mode, the slave
module address is determined by the ADDH
and ADDL.
When LBT is turned on, channel quality
will be checked before sending every data
packet; if quality is good, data will be sent
directly, if interference exists, data will be
sent after interference disappears.
It supports LBT only below air data rate
115200bps, LBT may affect the continuous
transmission function.
This bit is used to the module internal
pull-up resistor. It also increases the level's
adaptability in case of open drain. But in
some cases, it may need external pull-up
resistor.
The external power source must provide
100mA or above current output and ensure
the power ripple is lower than 100mV.
Low power transmission is not
recommended due to its low power supply
efficiency.
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