Data Exchange - WAGO 750-872/020-000 Manual

3.1.6 Data Exchange

The Telecontrol controller can be configured for either MODBUS/TCP or the
Ethernet IP protocol.
MODBUS/TCP works according to the master/ model. The master (e.g., a PC
or a PLC) will query a slave device and the slave will return a response to the
master depending on the kind of query. Queries are addressed to a specific
node through the use of the IP address.
Typically, the Telecontrol controller of the WAGO-I/O-SYSTEM is a slave
device. But, with the use of the WAGO-I/O-PRO CAA programming tool, the
PFC can additionally perform master functions.
A controller is able to produce a defined number of simultaneous socket
connections to other network subscribers:
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The maximum number of simultaneous connections may not be exceeded. If
you wish to establish further connections, terminate an existing connection
first.
For data exchange, the Telecontrol controller uses three main interfaces:
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Data exchange takes place between the fieldbus master and the I/O modules,
between the PLC functionality of the controller and the I/O modules as well as
between the fieldbus master and the PLC functionality of the controller.
Currently, the 750-872/020-000 supports MODBUS/TCP and ETHERNET IP
based master devices. When the controller performs PLC functions, and
controls various I/O modules, this is done with the use of an IEC 61131-3
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
3 connections for HTTP (read HTML pages from the controller),
15 connections via MODBUS/TCP (read or write input and output data
from the controller),
128 Ethernet IP connections,
5 connections via the PFC (available for IEC 61131-3 application
programs)
2 connections for WAGO-I/O-PRO CAA (these connections are reserved
for debugging the application program via ETHERNET.
For debugging, WAGO-I/O-PRO CAA requires 2 connections at the same
time. However, only one programming tool can have access to the
controller.
10 connections for FTP
2 connections for SNMP
interface to the fieldbus (master),
the PLC functionality of the PFCs (CPU) and
the interface to the I/O Modules.
Fieldbus Controller
Fieldbus Controller 750-872/020-000
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