Description - WAGO 750 Series Manual

36 • Fieldbus Controller 750-841

Description

3.1.1 Description
The WAGO 750-841 Programmable Fieldbus Controller (PFC) combines the
functionality of an ETHERNET fieldbus coupler with the functionality of a
Programmable Logic Controller (PLC). When the PFC is used as a PLC, all
or some of its I/O modules can be control locally with the use of WAGO-I/O-
PRO CAA. WAGO-I/O-PRO CAA is an IEC 61131-3 programming tool that
is used to program and configure the 750-841 PFC. I/O modules which are
not controlled locally, can be controlled remotely through the 10/100 Mbps
ETHERNET Fieldbus port.
When power is applied to the PFC, it automatically detects all I/O modules
connected to the controller and creates a local process image. This can be a
mixture of analog and digital modules. The process image is subdivided into
an input and an output data area.
The data of the analog modules is mapped first into the process image. The
modules are mapped in the order of their position after the controller. The
digital modules are grouped after the analog modules, in the form of words
(16 bits per word). When the number of digital I/O's exceeds 16 bits, the
controller automatically starts another word.
The controller has 512 KB of program memory, 128 KB of data memory, and
24 KB of retained memory. The programmer has access to all fieldbus and
I/O data.
To be able to send/receive process data via ETHERNET, the controller
supports a series of network protocols. For the exchange of process data, the
MODBUS TCP (UDP) protocol and the Ethernet/IP protocol are available.
Both communication protocols can be used alternatively or parallel.
The protocol HTTP, BootP, DHCP, DNS, SNTP, FTP, SNMP and SMTP are
provided for the management and diagnosis of the system.
The programmer has the option to use function modules for programming
clients and servers for all transport protocols (TCP, UDP, etc.) via a socket-
API.
Library functions are available to extend the range of programming functions.
The IEC 61131-3 library "SysLibRTC.lib" enables integration of a buffered
real time clock with date (1 second resolution), alarm function, and a timer. In
the event of a power failure, this clock is powered by an auxiliary supply.
The controller is based on a 32-bit CPU and is capable of multitasking (i.e.,
several programs can be run at the same time).
The controller has an internal server for web-based applications. By default,
the controller's built-in HTML pages contain information on the configuration
and status of the PFC, and can be read using a normal web browser. In
addition, a file system is implemented that allows you to store custom HTML
pages in the controller using FTP download.
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP