Ebyte E831-RTU Series User manual

E831-RTU(4040R-485)
User manual
This manual may be changed with the continuous improvement of the product. Please take the latest version
of the manual as the standard. Chengdu Ebyte Electronic Technology Co., Ltd. reserves the right to interpret
and modify all contents in this manual.

Contents
Features............................................................................................... 3
1. Quick start.......................................................................................3
1.1. Port connection......................................................................... 3
1.2. Simply use.................................................................................4
2. Introduction.....................................................................................6
2.1. Parameters.................................................................................6
2.2. Dimension&Interface................................................................7
2.3. Command reset......................................................................... 8
3. Modbus.............................................................................................8
3.1. Modbus address.......................................................................... 8
3.2. Modbus address......................................................................... 9
3.3. RS485 serial port baud rate....................................................... 9
3.4. RS485 serial port check bit...................................................... 10
3.5. Configure parameters via the upper computer........................10
4. Function..........................................................................................10
4.1. Mode selection.........................................................................10
4.2. IO basic function.......................................................................10
4.3. IO unique function................................................................... 12
Disclaimer.......................................................................................... 14
Revision history................................................................................. 14

Features

Support 4-channel digital isolation input, default dry contact;

Support 4-way relay output, support 3A 30VDC and 3A 250VAC;

Adopt Modbus RTU protocol for data processing;
 Command reset is supported. After sending the AT+RESTORE\r\n command to the 485 serial port
within 3S after power on, the Modbus device address, RS485 serial port baud rate and check bit are
restored to factory settings;
 Support pulse counting, which can be configured as rising edge counting, falling edge counting and
level counting
 Hardware watchdog with high reliability;

Three indicators display the working status;
 The power supply has good over-current, over-voltage, anti reverse connection and other functions;
 Wide voltage input 8V-28V. 12V or 24V is recommended.
1.Quick start
This chapter is a quick introduction to E831-RTU(4040R-485) series products. It is recommended that
users systematically read this chapter and operate it according to the instructions. They will have a
systematic understanding of the module products. Users can also choose the chapter you are interested in to
read according to their needs. For specific details and instructions, please refer to the following chapters.
1.1. Port connection
1.1.1 RS485 connection
Note: when the 485 bus high-frequency signal is transmitted, the signal wavelength is shorter than the
transmission line, and the signal will form a reflected wave at the terminal of the transmission line,
interfering with the original signal. Therefore, it is necessary to add a terminal resistor at the end of the
transmission line, so that the signal will not be reflected after reaching the end of the transmission line. The
terminal resistance should be the same as the impedance of the communication cable, with a typical value of
120 ohms. Its function is to match the bus impedance and improve the anti-interference and reliability of
data communication.
1.1.1 Switch input connection

1.1.1 Relay output connection
1.2. Simply use
Wiring: the computer is connected to E831-RTU(4040R-485) via USB to RS485.
Power supply: the working voltage of e831-rtu (4040r-485) is DC 8 ~ 28V. 12V or 24V is
recommended.
1.2.1. RS485 bus control
Set the corresponding port parameters and click “search” to search for devices.

After searching for the device, click “stop”
At this time, you can see the device address of the current device.
Click read parameter or write parameter to read parameters and configuration parameters.

Check auto refresh to read and configure input / output ports.
Note:Do not choose auto refresh when reading or writing parameters. Choose auto refresh after
configuration or reading is completed, otherwise the parameter writing or reading may not be successful
2. Introduction
E831-RTU(4040R-485) is an IO product that supports 4-way digital input (default dry contact) and 4-
way relay output. Support Modbus RTU protocol. This product is highly easy to use, and users can easily
and quickly integrate it into their own systems.
2.1. Parameters
Items
Index
Hardware
parameters
Size (H*W*D)
105*75*30mm
Weight
279g
Interface
Crimping，1*12*5.08mm
Working Voltage
DC8V~28V, 12V or 24V is recommended, over
28V may damage the equipment
Working current
12V@ 56mA standby current
Communication
interface
RS485：1200~115200bps
4-channel digital
input interface
Dry contact, DI acquisition frequency 1KHz
4-way relay output
Support 3A 30VDC、3A 250VAC

Baud rate
Baud rate range 1200~115200bps，
production default 9600
Working
temperature
-20℃~+70℃
Storage
temperature
-40℃~+85℃
Working
humidity
5%~95%
Storage
humidity
1%~95%
2.2. Dimension&Interface

Number
Port and
other
definitions
Function
Illustr
ation
1
PE
Connection with the earth
Connection with the earth
2
GND
Crimp type power supply
input negative pole
Power reference ground
3
VCC
Voltage type power
supply input positive pole
Power input terminal，DC 8V~28V，
12V/24V is recommended
4
RS485-G
RS485 Signal
reference ground
RS485 signal reference ground,
connection recommended
5
RS485-A
RS485 interface A
RS485 interface A is connected with
equipment A
6
RS485-B
RS485 interface B
RS485 interface B is connected with
equipment B
7
DI4
Digital input channel 4
Form dry contact with DIG
8
DI3
Digital input channel 3
Form dry contact with DIG
9
DIG
Digital input signal
reference ground
Digital input signal reference ground, used
with DI terminal
10
DI2
Digital input channel 2
Form dry contact with DIG
11
DI1
Digital input channel 1
Form dry contact with DIG
12
DIG
Digital input signal
reference ground
Digital input signal reference ground, used
with DI terminal

13
NO1
Relay 1 normally open
pin
Used in conjunction with the common end
of relay 1
14
COM1
Relay 1 common terminal
Used with relay 1 normally open pin /
normally closed pin
15
NC1
Relay 1 normally closed
pin
Used in conjunction with the common end
of relay 1

16
NO2
Relay 2 normally open pin
Used in conjunction with the common
end of relay 2
17
COM2
Relay 2 common terminal
Used with relay 2 normally open pin /
normally closed pin
18
NC2
Relay 2 normally closed pin
Used in conjunction with the common
end of relay 2
19
NO3
Relay 3 normally open pin
Used in conjunction with the common
end of relay 3
20
COM3
Relay 3 common terminal
Used with relay 3 normally open pin /
normally closed pin
21
NC3
Relay 3 normally closed pin
Used in conjunction with the common
end of relay 3
22
NO4
Relay 4 normally open pin
Used in conjunction with the common
end of relay 4
23
COM4
Relay 4 common end
Used with relay 4 N.O. pin / N.C. pin
24
NC4
Relay 4 normally closed pin
Used in conjunction with the common
end of relay 4
LED lamp
DAT
A
Serial port data indication
Dual color light, green indicates data reception, blue
indicates data transmission
I/O
I / O status indicator
Dual color light, the green indicator light of any input
signal is on, and the blue indicator light of any output
signal is on. When there are both outputs and inputs, it is
on at the same time, and the indicator light is cyan。
PWR
Power indication
Red LED, long on
Note：
Grounding: it is recommended to connect the housing to the earth
2.3. Command reset
Within 3 seconds after power on, send a command to 485 serial port: AT+RESTORE\r\n to reset the MODBU
address, serial port baud rate and parity parameters of the machine as default parameters (19600, no check).
3. Modbus
3.1. Modbus address
Register address （function code：0x01H、0x05H、0x0FH、0x03H、
0x06H、0x10H）
Register
address
Register
quantity
Register attribute
Register
type
Register
value range
Support
function
code
00017
(0x0010)
1
DO1 Switching output
Read / Write
0x0000 or
0xFF00
（0x05
function
code）0-1
（0x01、
0x0F
function
code）
0x01
0x05
0x0F
00018
(0x0011)
1
DO2 Switching output
Read / Write
00019
(0x0012)
1
DO3 Switching output
Read / Write
00020
(0x0013)
1
DO4 Switching output
Read / Write
Retain
10017
(0x0010)
1
DI1 Switching input
Read-only
0-1
0x02
10018
(0x0011)
1
DI2Switching input
Read-only

10019
(0x0012)
1
DI3 Switching input
Read-only
10020
(0x0013)
1
DI4 Switching input
Read-only
Retain
40049
(0x0030)
1
DI1 Pulse count
Read-only
0-65535
0x03
40050
(0x0031)
1
DI2 Pulse count
Read-only
0-65535
40051
(0x0032)
1
DI3 Pulse count
Read-only
0-65535
40052
(0x0033)
1
DI4 Pulse count
Read-only
0-65535
Retain
40065
(0x0040)
1
DI1-DI4 Pulse
count clearing
Write-only
0x00 - 0x0F
0x06
Retain
40078
(0x004D)
1
Device address
Read / Write
1 - 247
0x03
0x06
40079
(0x004E)
1
Baud rate
Read / Write
0 - 7

40080
(0x004F)
1
Check bit
Read / Write
0 - 2
0x10
40081
(0x0050)
1
Automatic reporting of
switching value
Read / Write
0 - 1
40082
(0x0051)
1
Switching output time setting
(MS)
Read / Write
100-65535
40083
(0x0052)
1
Switching restart output
state setting
Read / Write
0x00 -
0x10
40084
(0x0053)
1
Counting mode selection
Read / Write
0-2
40085
(0x0054)
1
Filter time setting
Read / Write
1-20
40086
(0x0055)
1
Manual / automatic clearing count
Read / Write
0-1
Retain
40300(0x012
B)
1
Version
Read-only
--
0x03
3.2. Modbus address
Modbus address
(default)
1
2
2
3
3
…
…
245
245
246
246
247
247
3.3. RS485 Serial port baud rate code value table
3.4. baud rate code value table
0
1200
1
2400
2
4800
（default）
9600
4
19200
5
38400
6
57600
7
11520
0
3.5. RS485 Serial port check bit code value table
check bit code value table
0
（default）
No
verification
1
Even check
2
Odd check
3.6. Configure parameters via the upper computer
Select the "parameter setting" column to read and write parameters. See the product function introduction
below for specific functions.

Note: when setting parameters, please clear "auto refresh" on the acquisition control page. So as to avoid
unsuccessful parameter writing.

4. Function
4.1. Mode selection
The device supports three pulse counting modes, rising edge counting, falling edge counting and level
counting. See the following section on pulse counting and zero clearing
4.2. IO basic function
4.2.1. Switching DO output
4.2.1.1. Read switch DO output
Functional code：01，read coil status
Address range：00017(0x0010)~00020(0x0013)
Example：
Read the output status of 4-channel digital quantity, assuming that the return value is 03,
corresponding to the binary bits 0000 and 0011, representing that DO1 and DO2 are open. The four bits
represent the digital output status, in order DO4、DO3、DO2、DO1.
Modbus RTU Protocol read digital output：
Send
01
01
00 10
00 04
3C 0C
equipment
ModBus
address
Function
code
Starting address
of switching
Read the
number
of
switching
CRC
check
code
Receive
01
01
01
03
11 89
equipment
ModBus
address
Function
code
Return
bytes
Digital
output
value
CRC
check
code
4.2.1.2. Control switching value DO output
Functional code：05，Write single coil
status；0F，Write multiple coil states.

Address range：
00017(0x0010)~00020(0x0013)
Example：

Function code 0x05 写DO2 digital output，write value is FF 00；close D02 port，write value 00 00。
（NC2 and COM2 of DO2 are disconnected, and
NO2 and COM2 are closed）Modbus RTU
Protocol write digital output：
Send
01
05
00 11
FF 00
DC 3F
equipment
ModBus
address
Function
code
Switching
value
address
Write
value
CRC
check
code
Receive
01
05
00 11
FF 00
DC 3F
equipment
ModBus
address
Function
code
Switching
value
address
Write
value
CRC
check
code
The function code 0x0f is used to write the digital output of DO2 and DO3. The written value
should be 0x03, corresponding to the binary bit 0000 0011. (note that the starting address here starts
from DO2.)
Modbus RTU protocol write digital output：
send
01
0F
00 11
00 02
01
03
62 95
equipment
ModBus
address
Function
code
Switching
value
address
Write
quantity of
switching
Bytes
Write
value
CRC
check
code
receive
01
0F
00 11
00 02
84 0F
equipment
ModBus
address
Function
code
Switchin
g value
address
Write
value
CRC
check
code
4.2.2. Read switching value DI input
Function code：02，read (switching value) input status
Address range：10017(0x0010)~10020(0x0013)
Note: the equipment defaults to dry contact input. When DI and DI are short
circuited, the read value should be 1; When DI and DIG are not short circuited, the
read value should be 0.
Example：
Read four digital input values. DI input terminals DI1 and dig are short circuited, DI2 and DIG are
not short circuited, DI3 and DIG are short circuited, and DI4 and dig are not short circuited. The read
digital input value is 0x05, corresponding to the binary bits 0000 0101. The four bits represent the
digital input value, which are DI4, DI3, DI2 and DI1 in sequence.
Modbus RTU protocol read digital input：
Send
01
02
00 10
00 04
78 0C
equipment
ModBus
address
Function
code
Starting
address of
switching
value
Read the
number of
switching
values
CRC check code
Receive
01
02
01
05
61 8B
equipment
ModBus
address
Function
code
Return
bytes
Digital
input
value
CRC check
code

4.3. IO unique functions
4.3.1. Pulse counting and count clearing
The device supports three pulse counting modes, rising edge counting, falling edge counting and
level counting，This value can be set by writing the corresponding value to the (0x0053) register，
Write 0 to represent the rising edge count, write 1 to represent the falling edge count, and write 2 to
represent the level count. If counting on rising edges is selected, only when DI detects the rising
edge of the level will it count. Other functions are similar.
In addition, the device also supports the input counting and filtering function, and the signal must
be kept for several cycles before being confirmed. The default value is 6, 6 sampling cycles before
it can be confirmed. The range is 1 ~ 20 values. This value can be set by writing the corresponding
value to the (0x0054) register. The sampling cycle is 1ms. Note that this function only supports
level counting mode. Pulse count will not be saved after power failure.
Count clearing also supports manual clearing and automatic clearing functions: automatic clearing after
reading the input count, or manual clearing, which can be set. If it is auto cleared, the register value will be
cleared after each reading. If it is manually cleared, the maximum count value 65536 will be reached or the
write register will be cleared. Write 0 to the (0x0055) register for manual zero clearing, and write 1 for
automatic zero clearing. Note that when it is set to automatic zero clearing, manual zero clearing will not
work.
4.3.1.1. Read pulse count
Function code：03，Read hold register
Address arrange：40049 (0x0030)~40051 (0x0033)
Description：The maximum
value of pulse count is65535
Example：
DI1 has detected 16 pulses and DI2 has detected 3 pulses. Read the digital input
count values of DI1 and DI2,
Modbus RTU protocol read pulse count：
Send
01
03
00 30
00 02
C4 04
Equipment
ModBus
address
Function
code
Starting
address
Number of reads
CRC
check
code
Receive
01
03
04
00 10
00 03
BB F7
Equipment
ModBus
address
Function
code
Return
bytes
DI1 count value
DI2
count
value
CRC
check
code
4.3.1.2. Manually clear the pulse count value
Function code：06，
Write hold
Address range of
holding register：40065
(0x0040)
Note: the lower four bits of the register value represent DI4, DI3, DI2 and DI1 counts
respectively. Writing "1" means that the count is cleared and the pulse count is restarted.
Example：
Clear di2 and Di4 pulse count values and keep di1 and di3 pulse count values. The write

value should be 0x0a and the corresponding binary value is 0000 1010,
Modbus RTU protocol clear pulse count
Send
01
06
00 40
00 0a
08 19
Equipment
ModBus
address
Function
code
Address
Write value
CRC
check
code
Receive
01
06
00 40
00 0a
08 19
Equipment
ModBus
address
Function
code
Address
Write value
CRC
check
code
4.3.2. Digital input DI automatic reporting
The automatic reporting function of digital input is to transmit the change value when the
switching value changes. You can choose to transmit through RS485 or GPRS, or turn off the automatic
reporting function.
The Modbus register corresponding to the switch value automatic
reporting setting is 40081 (0x0050), and the value corresponds to
the function:
0，Turn off the automatic reporting function of switching value
1，Automatic reporting of switching value is transmitted through RS485
The switch quantity change upload protocol is shown in the following table, where the frame
headers 0XAA and 0xBB are fixed. When the counting mode is set to level counting, the value range of
DI1, DI2, DI3, DI4 is 0x00, 0x01 and 0xFF
0x00 Digital quantity input disconnection,
0x01 Digital input closed，

0xff Digital input has not changed，
The values of DI1, DI2, DI3 and DI4 in the table represent that the status of DI1 and DI2 is
updated to off, the status of DI3 is updated to close, and the status of DI4 is unchanged. The last two
bytes are calculated values of Modbus CRC16.
Note: when set to the rising edge counting mode, it is triggered once, and the value of Di is 00;
when set to the falling edge counting mode, it is triggered once, and the value of Di is 01. Similarly 0xff
means no change.变化。
Frame
header
DI1
DI2
DI3
DI4
Modbus
CRC
0xAA
0xBB
0x0
0
0x0
0
0x0
1
0xff
0xBD
0xDA
4.3.3. Digital output DO time setting
The setting of switching value pulse output time is to set the digital output time. The
corresponding MODBUS register is 40083 (0x0052), and its value range is 100-65535ms. If
the value is lower than 100ms, the digital output is closed to hold state by default, that is, the
digital output is held after being closed. If it is set to 100ms or above, such as 500ms, after
sending the digital output closing command, the switching value will be closed for 500ms,
and then automatically opened after 500ms.
4.3.4. Switching value DO restart output state setting
The setting of whether to keep the state before power-off or to keep a specific output state after power-
off and restart of the equipment. This function is only effective when the value of the digital output time
setting register of the equipment is less than 100ms.
The Modbus register corresponding to the reset output state setting of switching value is 40085
(0x0054), and its value range is 0x00-0x10. When the value of this register is 0x10, the last digital
output state will be maintained after power-off and restart; When the value of this register is 0x00-0x0f,
the low four bits determine the output state of the device restart digital quantity. Bit4 corresponds to do4,
Bi3 corresponds to do3, bit2 corresponds to DO2, and Bit1 corresponds to do1. For example, when
powered on, do4 and DO2 are in the closed state (relay no and com are closed) and do3 and do1 are in
the open state (relay no and com are open). The corresponding register value is 0000 1010, that is 0xa0,
"1" is in the closed state and "0" is in the open state.
Disclaimer
 Ebyte reserves the right of final interpretation and modification of all contents in this manual.

Due to the continuous improvement of the hardware and software of the product, this manual may be
changed without notice, and the latest version of the manual shall prevail.

Protecting the environment is everyone's responsibility: to reduce the use of paper, this manual is printed in
Chinese only, and the English manual is only provided with electronic documents. If necessary, please
download it from our official website; In addition, unless specifically required by the user, when the user
orders in batches, we only provide product specifications according to a certain proportion of the order
quantity, and not every digital radio station is equipped with them one by one. Please understand.
Revision history

Version
Date
Description
Maintainer
1.0
-
Initial version
-
1.1
2019/8/19
Format revision
Linson
About us
Technical support: [e-mail]
Documents and RF Setting download link: www.ebyte.com
Thank you for using Ebyte products! Please contact us with any questions or suggestions: [e-mail]
-------------------------------------------------------------------------------------------------
Phone: [phone]
Web: www.ebyte.com
Address: B5 Mould Park, 199# Xiqu Ave, High-tech District, Sichuan, China