Search This Blog

Communication protocols in PLC


Ethernet /IP

works under Common Industrial Protocol (CIP)
Advanced version of Standard ethernet
Developed by Rockwell Automation

Similar protocols will be as follows

Profinet
ControlNet
DeviceNet
RAPIEnet
Modbus

Protocol that is used for transmitting information over a serial lines or ethernet, based on master-slave technology.

Protocol developed by Modicon (now schneider electric)
Two types of devices

Modbus master
Device which request information

Modbus Slaves
Devices which provide the information

Types
Modbus RTU

Modbus ASCII
Modbus TCPIP


Profibus
Similar to Modbus RTU, which also works on serial line communication.
Owned by Siemens Automation