Instruction Manual

25
modbus/TCP Extensions
The Modbus Applications Programming Interface for Network Communications, (MBAP), was developed
by Modicon to allow traditional serial modbus communiactions to occur over a TCP/IP network. It
basically defines a “wrapper” around the modbus protocol to accomidate routing data packets between two
network nodes. The same master/slave messaging protocol is used, however the network aspect allows
multiple master devices to access data from the same or different slave devices connected to the network.
Using the Client/Server approach, a modbus/TCP slave device represents the server side of the
communications model, accepting and responding to queires from one or more network client master
applications.