What is Modbus?

What is Modbus protocol ?
 
Modbus is a communication protocol developed by MODICON Inc. in 1979. It's a standard, truly open and the most widely used network communication protocol in industrial automation field. SCADA and HMI software can easily integrate serial devices together via Modbus protocol.
 
What is Modbus/TCP protocol ?
 
Modbus/TCP protocol is a variant of Modbus protocol. It was developed in 1999 to allow Internet community access Ethernet devices.
 
What software supports Modbus and Modbus/TCP protocol ?
 
Most of SCADA ( Supervisor Control And Data Acuisition ) and HMI software support Modbus. For example: Citect, ICONICS, iFIX, InduSoft, Intouch, Entivity Studio, Entivity Live, Entivity VLC, Trace Mode, Wizcon, Wonderware... etc
 
What are the benefits of using Modbus and Modbus/TCP protocol ?
 
    1. Openness, no license fees.
    2. Widely supported by SCADA and HMI software
    3. Easy to use
    4. Easily integrate variant devices
    5. Low development cost
    6. Widely knowledge resource