Data Exchange - WAGO 750-306 Technical Description

3.1.5 Data Exchange

With DeviceNet, the transmission and exchange of data is made using objects.
For a network access on the single objects of the Coupler, it is necessary to
create a connection between the desired participants and to allocate connection
objects.
For an easy and quick set-up of a connection, the DeviceNet fieldbus Coupler
750-306 uses the "Predefined Master/Slave Connection Set", which contains 4
pre-defined connections. For the access on the Coupler the connections only
need to be allocated. The "Predefined Master/Slave Connection Set" confines
itself to pure Master/Slave relationships.
The DeviceNet fieldbus Coupler 750-306 can only communicate via its as-
signed client and it is a so-called "Group 2 Only Server". The Group 2 Only
Server communicating is only possible via the Group 2 Only Unconnected
Explicit Message Port. These slaves exclusively receive messages defined in
message group 2.
The object configuration for the data transmission is defined by an Assembly
Object. The Assembly Object can be used to group data (e.g. I/O data) into
blocks (mapping) and send this data via one single communication connection.
This mapping results in a reduced number of accesses to the network.
A differentiation is made between "Input-Assemblies" and "Output-
Assemblies".
An Input-Assembly reads in data from the application via the network or pro-
duces data on the network respectively.
An Output-Assembly writes data to the application or consumes data from the
network respectively.
Various Assembly instances are permanently programmed (static assembly) in
the fieldbus Coupler.
Further information
The Assembly instances for the static assembly are described in chapter
5.5.1.1 "Assembly Instance".
WAGO-I/O-SYSTEM 750
DeviceNet
Fieldbus Coupler/Controller • 47
Fieldbus Coupler 750-306