WAGO I/O SYSTEM 750 XTR
Run-time System CODESYS 2.3 281
750-8202/040-001 PFC200 2ETH RS TELE XTR
Manual
Version 1.2.0, valid from FW Version 03.01.07(13)
Frequently Asked Questions
Additional information (FAQs) on CODESYS Web visualization is also provided
in the Section “Frequently Asked Questions about CODESYS Web Visualization”
and in the online Help function for CODESYS 2.3.
8.11.1 Limits of CODESYS Visualization
The controller supports the “WebVisu” visualization type integrated into
CODESYS. Technological limitations can be caused by the visualization type
used.
Compared to “HMI”, Web visualization on the controller is performed within
significantly narrower physical limits. Whereas “HMI” can access almost unlimited
resources on a desktop PC, the following limitations must be observed when
using Web visualization:
Adapting to the File System
The overall size of the PLC program, visualization files, bitmaps, log files,
configuration files, etc. must fit into the file system.
Process Data Memory
Web visualization uses its own protocol for exchanging process data between
applet and control.
The controller transfers process data with ASCII coding. The pipe symbol (“|”) is
used to separate two process values. Therefore, the space requirement for a
process data variable in the process data memory is dependent not only on the
data type, but also on the process value itself. Thus, a variable of the “WORD”
type occupies between one byte for the values 0 through 9 and five bytes for
values from 10000 and greater. The selected format (ASCII + |) only permits a
rough estimate of the space requirement for the individual process data in the
process data buffer. If the size of the ASCII coded process data is exceeded,
Web visualization no longer works as expected.
Computer Performance/Processor Time
The controller is based on a real-time operating system. This means that high-
priority processes (e.g., PLC program) interrupt or block lower priority processes.
The Web server responsible for Web visualization is among these lower priority
processes.
