182 lines
4.4 KiB
Markdown
182 lines
4.4 KiB
Markdown
## MyEMS Modbus TCP Service
|
|
|
|
### Introduction
|
|
This service is a component of MyEMS to acquire data from Modbus TCP devices.
|
|
|
|
### Prerequisites
|
|
|
|
mysql-connector-python
|
|
|
|
modbus_tk
|
|
|
|
schedule
|
|
|
|
python-decouple
|
|
|
|
|
|
### Quick Run for Development
|
|
|
|
```bash
|
|
pip install -r requirements.txt
|
|
chmod +x run.sh
|
|
run.sh
|
|
```
|
|
|
|
### Installation
|
|
|
|
Download and install MySQL Connector:
|
|
```bash
|
|
cd ~/tools
|
|
wget https://cdn.mysql.com/archives/mysql-connector-python-8.0/mysql-connector-python-8.0.23.tar.gz
|
|
tar xzf mysql-connector-python-8.0.23.tar.gz
|
|
cd ~/tools/mysql-connector-python-8.0.23
|
|
python3 setup.py install
|
|
```
|
|
|
|
Download and install Schedule
|
|
```bash
|
|
cd ~/tools
|
|
git clone https://github.com/dbader/schedule.git
|
|
cd ~/tools/schedule
|
|
python3 setup.py install
|
|
```
|
|
|
|
Download and install modbus-tk
|
|
```bash
|
|
cd ~/tools
|
|
git clone https://github.com/pyserial/pyserial.git
|
|
cd ~/tools/pyserial
|
|
python3 setup.py install
|
|
git clone https://github.com/ljean/modbus-tk.git
|
|
cd ~/tools/modbus-tk
|
|
python3 setup.py install
|
|
```
|
|
|
|
Download and install Python Decouple
|
|
```bash
|
|
cd ~/tools
|
|
git clone https://github.com/henriquebastos/python-decouple.git
|
|
cd ~/tools/python-decouple
|
|
python3 setup.py install
|
|
```
|
|
|
|
Install myems-modbus-tcp service
|
|
```bash
|
|
cd ~
|
|
git clone https://github.com/MyEMS/myems.git
|
|
cd myems
|
|
git checkout master (or the latest release tag)
|
|
cp -R ~/myems/myems-modbus-tcp /myems-modbus-tcp
|
|
```
|
|
Create .env file based on example.env and edit the .env file if needed:
|
|
```bash
|
|
cp /myems-modbus-tcp/example.env /myems-cleaning/.env
|
|
nano /myems-modbus-tcp/.env
|
|
```
|
|
Setup systemd service:
|
|
```bash
|
|
cp myems-modbus-tcp.service /lib/systemd/system/
|
|
```
|
|
Enable the service:
|
|
```bash
|
|
systemctl enable myems-modbus-tcp.service
|
|
```
|
|
Start the service:
|
|
```bash
|
|
systemctl start myems-modbus-tcp.service
|
|
```
|
|
Monitor the service:
|
|
```bash
|
|
systemctl status myems-modbus-tcp.service
|
|
```
|
|
View the log:
|
|
```bash
|
|
cat /myems-modbus-tcp.log
|
|
```
|
|
|
|
### Add Data Sources and Points in MyEMS Admin
|
|
|
|
NOTE: If you modified Modbus TCP datasources and points, please restart this service:
|
|
```bash
|
|
systemctl restart myems-modbus-tcp.service
|
|
```
|
|
|
|
Input Data source protocol:
|
|
```
|
|
modbus-tcp
|
|
```
|
|
Data source connection example:
|
|
```
|
|
{"host":"10.9.67.99","port":502}
|
|
```
|
|
|
|
Point address example:
|
|
```
|
|
{"slave_id":1, "function_code":3, "offset":0, "number_of_registers":2, "format":"<f", "byte_swap":true}
|
|
```
|
|
|
|
### Address
|
|
|
|
#### slave_id
|
|
The slave ID
|
|
|
|
#### function_code
|
|
```
|
|
01 (0x01) Read Coils
|
|
02 (0x02) Read Discrete Inputs
|
|
03 (0x03) Read Holding Registers
|
|
04 (0x04) Read Input Registers
|
|
23 (0x17) Read/Write Multiple registers
|
|
```
|
|
|
|
#### offset
|
|
The starting register address specified in the Request PDU
|
|
|
|
#### number_of_registers
|
|
The number of registers specified in the Request PDU
|
|
|
|
#### format
|
|
Use python3 library struct to format bytes.
|
|
Python bytes objects are used to hold the data representing the C struct
|
|
and also as format strings (explained below) to describe the layout of data in the C struct.
|
|
|
|
The optional first format char indicates byte order, size and alignment:
|
|
@: native order, size & alignment (default)
|
|
=: native order, std. size & alignment
|
|
<: little-endian, std. size & alignment
|
|
>: big-endian, std. size & alignment
|
|
!: same as >
|
|
|
|
The remaining chars indicate types of args and must match exactly;
|
|
these can be preceded by a decimal repeat count:
|
|
x: pad byte (no data); c:char; b:signed byte; B:unsigned byte;
|
|
?: _Bool (requires C99; if not available, char is used instead)
|
|
h:short; H:unsigned short; i:int; I:unsigned int;
|
|
l:long; L:unsigned long; f:float; d:double.
|
|
|
|
Special cases (preceding decimal count indicates length):
|
|
s:string (array of char); p: pascal string (with count byte).
|
|
Special cases (only available in native format):
|
|
n:ssize_t; N:size_t;
|
|
P:an integer type that is wide enough to hold a pointer.
|
|
|
|
Special case (not in native mode unless 'long long' in platform C):
|
|
q:long long; Q:unsigned long long
|
|
|
|
Whitespace between formats is ignored.
|
|
|
|
#### byte_swap
|
|
A boolean indicates whether or not to swap adjacent bytes.
|
|
Swap adjacent bytes of 32bits(4bytes) or 64bits(8bytes).
|
|
This is not for little-endian and big-endian swapping, and use format for that.
|
|
The option is effective when number_of_registers is ether 2(32bits) or 4(64bits),
|
|
else it will be ignored.
|
|
|
|
### References
|
|
[1]. http://myems.io
|
|
|
|
[2]. http://www.modbus.org/tech.php
|
|
|
|
[3]. https://github.com/ljean/modbus-tk
|
|
|
|
[4]. https://docs.python.org/3/library/struct.html#format-strings |