MODBUS Plugin Configuration and test
MODBUS is an application layer messaging protocol, positioned at level 7 of the OSI model, that provides client/server communication between devices connected on different types of buses or networks.
It is currently implemented using:
TCP/IP over Ethernet at a reserved system port 502 on the TCP/IP stack
Asynchronous serial transmission
MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs.