IoT Protocol -- Modbus

OSI vs. Modbus Layers:

Tip:

• RS-485/RS485’s new name is EIA-485.
• UART usually (99%) means TTL in shops, not 232/485.
• DB9 physical port usually (90%) means 232 electrical signals level standards.

Modbus Protocol #

See Also：

• 【strongly recommend！】 a nice intro to Modbus and Modbus Enron. (Simply Modbus 软件收费，但是这个 Modbus 入门文档非常好)
• 一文看懂 Modbus 协议
• Complete Modbus Guide.
• a good intro to Modbus.

Each Modbus Slave has 4 tables with 9999 values in each table.

MQTT

Server #

ActiveMq Classic #

Require: JAVA_HOME (JDK is preferred than JRE, if in development, as JRE ∈ JDK. 150MB) && reboot.

e.g.: Apache ActiveMq (ref, bak).

cd bin
./activemq-admin.bat create mybroker
cd mybroker/bin/
mybroker.bat start

http://127.0.0.1:8161/

EMQX #

Require: Erlang (150MB) (will install MS VC++ Redist. 2015).

ref

download #

https://www.emqx.io/downloads?os=Windows

hands-on #

web: localhost:18083 default account: admin/public

ref: EMQX dashboard, bak

ref: EMQX+Prometheus+Grafana：MQTT 数据可视化监控实践, bak

Client #

e.g. MQTTX, Chrome MQTTBox, etc.