Ebyte E820-AIO User manual

1
Data Acquisition Module
E820-AIO
User Manual
This manual may be modified based on product upgrade, please refer to the latest version.
All rights to interpret and modify this manual belong to Chengdu Ebyte Electronic Technology Co., Ltd.

2
Version
Date
Description
Issued by
1.00
2018/01/23
Initial version
huaa
E820-AIO is the analog signal collection product designed by Ebyte. With RS485 communication network, E820-AIO transmits the
analog signal of scattered field data point via AD transformation to master or control remote home site via the PC. Built-in watch dog (0.2s
reset), the system won’t be halted easily. E820-AIO analog acquisition module features measurement data collection, measured data
collection, device switch status collection etc, mainly used for the data collection, controlling and device display of various measurement
and control terminal, suitable for the automation and information systems in various industries.
Features
Wide working temperature range: working at -40℃～+65℃, suitable for harsh working environment.
Non directional design of input power: This can avoid misconnection and over connection damage, increasing the reliability.
Modbus protocol: Q&A communication, easy to use and featuring cheap hardware and strong universal property.
High acquisition accuracy: it’s 0.1%FS.
All aluminum alloy shell: Good EMS performance, compact size, easy installation and good heat dissipation.
Watch dog: This can conduct the precise time layout. Once any exception occurs, the module will restart in 0.2s and continue to
work as previous parameters.

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1. Electrical Parameters
1.1 E820-DTU（AI-485-4-5）
No
Parameter Name
Parameter value
Description
1
Size
82 * 84 *25mm
Pressing line interface is not included.
2
Average weight
150g
Pressing line interface is not included.
3
Input signal type
0—20mA/0-5V
Analog signal input range.
4
Acquisition channel
4 channel input
4 channel current collection and all differential voltage acquisition.
5
Acquisition rate
Full channel 10Hz
Acquisition rate for analog signal.
6
Interface
RS485：1 * 5 * 3.81 mm
Pressing line
7
Supply voltage
8 ~ 28V DC
Note: The module will be destroyed if the voltage is higher than 28V.
8
Working current
40mA
The over 100mA output current is recommended(when the output power is not used).
9
Communication level
RS232/RS485
RS232 or RS485.
10
Communication address
1-250
1-250 can be configurable, the default is 1.
11
Acquisition accuracy
0.1%FS
Accuracy of analog signal collection.
12
Baud rate
Default: 9600
It can be configured from 1200~115200.
13
Working temperature
-40℃～+65℃
Industrial grade.
14
Isolation protection
4000vDC
Lightening strike, Surge protection.
1.2 E820-DTU（II-485-4-20）
No
Parameter Name
Parameter value
Description
1
Size
82 * 84 *25mm
Pressing line interface is not included.
2
Average weight
150g
Pressing line interface is not included.
3
Input signal type
0—20mA
Analog signal input range.
4
Acquisition channel
4 channel input
4 channel Single-ended input of analog signal.
5
Acquisition rate
Full channel 10Hz
Acquisition rate for analog signal.
6
Interface
RS485：1 * 5 * 3.81 mm
Line pressing
7
Supply voltage
10 ~ 28V DC
Note: The module will be destroyed if the voltage is higher than 28V.
8
Working current
31mA
The over 100mA output current is recommended(when the output power is not used).
9
Communication level
RS232/RS485
RS232 or RS485
10
Communication
address
1-250
1-250 can be configurable, the default is 1.
11
Acquisition accuracy
0.1%FS
Accuracy of analog signal collection.
12
Baud rate
Default: 9600
It can be configured from 1200~115200.
13
Working temperature
-40℃～+65℃
Industrial grade.
14
Isolation protection
4000vDC
Lightening strike, Surge protection.
1.3 Series products
Model Number
Interface
Signal type
Acquisition accuracy
Analog channel
Protection level
VDC
Size
E820-DTU
（II-485-4-20）
RS485
0-20mA
0.1%FS
4
3000
82*84.25
E820-DTU
（VI-485-4-5）
RS485
0-5V
0.1%FS
4
3000
82*84.25

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1.4 FAQ
No.
Questions
Description
1
Change baud rate
When using the upper computer, users need to close the upper computer first and reopen after changing the baud rate.
2
Forget the device address
Users can use 03 command to read FF monitoring.
1.5 Notice
No.
Notice
Description
1
Communication
connection
In connecting with other RS485 device, users need to pay attention to the match of A, B line and add 120R
matching resistance.
2
Input voltage
Only DC power supply is available, and the DC input voltage should be 10-28V
The device won’t work when lower than 10V, while the device will be destroyed when higher than 28V,
3
Output power supply
The positive and negative directions of output power is same with the input power. See more details in Pin
definition.
4
Analog input interface
The collection signal is 0-20Ma/0-5V, so user do not input the exceed nominal measured value, or it may cause
damage.
5
Waterproof
The device is not waterproof, please do not get the device wet, or it will be damaged.

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2. Function Description
2.1 Pin definition
2.1.1 E820-DTU（AI-485-4-5）

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Pin
Definition
Function
Description
1
DC-IN
Pressing line power input positive
Power input, range: DC10-28V. 12V, and 24V are recommended.
2
GND
Pressing line power input negative
Power supply GND.
3
AGND
Communication common ground
When communicating with RS485, the DTU won’t be used, while when
communicating with RS232, it will be grounded.
4
RS485_B
Interface B of RS-485
Interface B of RS-485 connected to Device B.
5
RS485_A
Interface A of RS-485
Interface A of RS-485 connected to Device A.
6
AI1+
Analog signal input channel 1 positive
Input pin of analog signal forms the input with the GND1 pin.
7
AI1-
Analog signal input channel 1 negative
To be used in pairs with VI1+.
8
AI2+
Analog signal input channel 2 positive
Input pin of analog signal, forms the input with the GND2 pin.
9
AI2-
Analog signal input channel 2 negative
To be used in pairs with VI2+.
10
AI3+
Analog signal input channel 3 positive
Input pin of analog signal, forms the input with the GND3 pin.
11
AI3-
Analog signal input channel 3 negative
To be used in pairs with VI3+.
12
AI4+
Analog signal input channel 4 positive
Input pin of analog signal forms the input with the GND4 pin.
13
AI4-
Analog signal input channel 4 negative
To be used in pairs with VI4+.
14
GND
Power supply output negative
The negative internal of power supply connected to pin 2 GND.
15
OUT-DC
Power supply output positive
Power supply output, the voltage is decided by the pin 1(internal connecting to
pin 1).

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2.1.2 E820-DTU（II-485-4-20）

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Pin
Definition
Function
Description
1
DC8-28V
Pressing line power input positive
Power input, range: DC10-28V. 12V, and 24V are recommended.
2
AI-
Pressing line power input negative
Power supply AI-.
3
AAI-
Communication common ground
When communicating with RS485, the DTU won’t be used, while when
communicating with RS232, it will be grounded.
4
RS485_B
Interface B of RS-485
Interface B of RS-485 connected to Device B.
5
RS485_A
Interface A of RS-485
Interface A of RS-485 connected to Device A.
6
AI1+
Analog signal input channel 1 positive
Input pin of analog signal forms the input with the AI1-.
7
AI1-
Analog signal input channel 1
negative
To be used in pairs with AI1+.
8
AI2+
Analog signal input channel 2 positive
Input pin of analog signal forms the input with the AI2-.
9
AI2-
Analog signal input channel 2
negative
To be used in pairs with AI2+.
10
AI3+
Analog signal input channel 3 positive
Input pin of analog signal forms the input with the AI3-.
11
AI3-
Analog signal input channel 3
negative
To be used in pairs with AI3+.
12
AI4+
Analog signal input channel 4 positive
Input pin of analog signal forms the input with the AI4-.
13
AI4-
Analog signal input channel 4
negative
To be used in pairs with AI4+.
14
AI-
Power supply output negative
The negative internal of power supply connected to AI-.
15
OUT-DC
Power supply output positive
Power supply output, the voltage is decided by the pin 1 (internal connecting to
pin 1).
2.2 Connection method
2.2.1 RS485 connection method

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3. Register configuration table
3.1 ModBus address table
40001—40012、40017—40028、40042—40049 is not used in this device.
ModBus register address table
Address
Byte
variable names
Type
Description
40013
2
AI1 input
Read only
Unit 0.001mA/0.001V
40014
2
AI2 input
Read only
40015
2
AI3 input
Read only
40016
2
AI4 input
Read only
40029
2
reference voltage for channel 1
Read/write
Default 2400，Max. 3300，Min 2000，Unit 0.001V
40030
2
reference voltage for channel 2
Read/write
40031
2
reference voltage for channel 3
Read/write
40032
2
reference voltage for channel 4
Read/write
40033
2
ModBus address
Read/write
1-250（0xff is the monitoring address）
40034
2
Baud rate
Read/write
see more in baud rate table
40035
2
parity bit
Read/write
see more in parity bit table
40036
2
Lower limit register
Read/write
0-65535（Lower limit register must be less than the Upper limit
register . After the configuration, channel 1-4 will be the range
of upper and lower limits.
40037
2
Upper limit register
Read/write
40038
2
Conversion value for channel 1
Read only
The original data value transformed by the analog quantity of
channel 1
40039
2
Conversion value for channel 2
Read only
The original data value transformed by the analog quantity of
channel 2
40040
2
Conversion value for channel 3
Read only
The original data value transformed by the analog quantity of
channel 3
40041
2
Conversion value for channel 3
Read only
The original data value transformed by the analog quantity of
channel 4
3.2 Baud rate code table
Baud rate code table
0
1200
1
2400
2
4800
3（default）
9600
4
19200
5
38400
6
57600
7
1152200
3.3 Parity bit code table
Parity bit code table
0（default）
No parity
1
Even parity
2
Odd parity

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4. Instruction format
4.1 Input“03”to read the command of single register
Users input”03” to read the command of register value. Below is the command to read the value of baud rate:
01
03
00 21
00 01
D4 00
ModBus Address
To read command
To read the address of register
To read the length of register
CRC parity code
Send above command via the serial assistant to module, then below value will be returned:
01
03
02
00 03
F8 48
ModBus Address
To read command
To read the return bytes
The value of 40034 is 3，which means
the baud rate is 9600，see more
details in baud rate value table.
CRC parity code
Note: With the known baud rate, to use FF monitoring address can read the unremembered register value, Such as, send FF 03 00 21 00 01
c1de to read the address of device. CRC parity check code can be calculated by CRC16 system, the assistant software can be downloaded
in official website.
4.2 Input“03”to read the command of multiple registers
Users input”03” to read the command of register value. Below is the command to read the address of 40034 to 40036:
01
03
00 21
00 03
55 C1
ModBus address
To read command
To read the address of register
To read the length of register
CRC parity code
Send above command via the serial assistant to module, then below value will be returned:
01
03
06
00 03
00 00
00 00
65 75
ModBus
address
To read command
To read the
return bytes
The value of 40034 is 3，
which means the baud
rate is 9600，see more
details in baud rate value
table.
The value of 40035 is 0,
the parity bit of device
is no parity, see more
details in parity check
code table.
The value of 40036 is 0
CRC parity code
4.3 Input “06” to write the command of register
Input “06”to write single command, below is the command to change the baud rate as 19200：
01
06
00 21
00 04
D8 03
ModBus address
To write command
Write in 40034 register
The write value of 40034 is 4, the
corresponding baud rate is 19200,
see more details in baud rate table
CRC parity code
If the revision is successful, module will return 01 06 00 21 00 04 d803.
4.4 Factory default value
Device address
Baud rate
Voltage for reference
Parity check code
40033 address is 1
9600，that is, 40034 address is 3
2400
No parity check：40035 address is 0