Chengdu Ebyte Electronic Technology Co., Ltd
E32-900T20D User Manual
Copyright ©2012–2021
，
Chengdu Ebyte Electronic Technology Co.,Ltd.
16
2
ADDL
Low address byte of module
（
the default 00H
）
00H-FFH
3
SPED
7
6
UART parity bit
UART mode can be different between
communication parties
0
0
8N1 (default)
0
1
8O1
1
0
8 E1
1
1
8N1 (equal to 00)
5
4
3
TTL UART baud rate
（
bps
）
UART baud rate can be different between
communication parties
The UART baud rate has nothing to do
with wireless transmission parameters &
won’t affect the wireless transmit / receive
features.
0
0
0
1200
0
0
1
2400
0
1
0
4800
0
1
1
9600 (default)
1
0
0
19200
1
0
1
38400
1
1
0
57600
1
1
1
115200
2
1
0
Air data rate
（
bps
）
The lower the air data rate, the longer the
transmitting
distance,
better
anti-interference performance and longer
transmitting time
The air data rate must keep the same for
both communication parties.
0
0
0
0.3k
0
0
1
1.2k
0
1
0
2.4k (default)
0
1
1
4.8k
1
0
0
9.6k
1
0
1
19.2k
1
1
0
19.2k (same to 101)
1
1
1
19.2k (same to 101)
General Specifications
4
CHAN
7
6
5
reserved
Write 0
Communication channel
00H-45H, correspond to 862~931MHz
4-0, channel (862M + CHAN*1M), default 06H
（
868MHz
）
5
OPTI
ON
7
Fixed transmission enabling bit
（
similar to MODBUS
）
In 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.
0
Transparent transmission mode
1
Fixed transmission mode
6
IO drive mode (default 1)
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.
1
TXD and AUX push-pull outputs, RXD pull-up inputs
0
TXD
、
AUX open-collector outputs, RXD open-collector
inputs
