104BWeb server
11.3 User-defined web pages
S7-1200 Programmable controller
512
System Manual, 11/2011, A5E02486680-05
Description
In this application, each wind turbine in a wind turbine farm is equipped with an S7-1200 for
control of the turbine. Within the STEP 7 program, each wind turbine has a data block with
data specific to that wind turbine and location.
The user-defined Web page provides remote turbine access from a PC. A user can connect
to standard web pages of the CPU of a particular wind turbine and access the user-defined
"Remote Wind Turbine Monitor" Web page to see the data for that turbine. An admin user
can also put the turbine in manual mode and control the variables for turbine speed, yaw,
and pitch from the Web page. An admin user can also set a braking value regardless of
whether the turbine is under manual or automatic control.
The STEP 7 program would check the Boolean values for overriding automatic control, and if
set, would use the user-entered values for turbine speed, yaw, and pitch. Otherwise, the
program would ignore these values.
Files used
This user-defined Web page example consists of three files:
●
Wind_turbine.html: This is the HTML page that implements the display shown above,
using AWP commands to access controller data.
●
Wind_turbine.css: This is the cascading style sheet that contains formatting styles for the
HTML page. Use of a cascading style sheet is optional, but it can simplify the HTML page
development.
●
Wind_turbine.jpg: This is the background image that the HTML page uses. Use of images
in user-defined Web pages is, of course, optional, and does require additional space in
the CPU.
These files are not provided with your installation, but are described as an example.
Implementation
The HTML page uses AWP commands to read values from the PLC (Page 495) for the
display fields and to write values to the PLC (Page 496) for data coming from user input.
This page also uses AWP commands for enum type definition (Page 501) and reference
(Page 501) for handling ON/OFF settings.
The first part of the page displays a header line that includes the wind turbine number and
the location.
The next part of the page displays atmospheric
conditions at the wind turbine. These fields are
supplied from I/O at the turbine site that provide
the wind speed, wind direction, and current
temperature.
Next, the page displays the power output of the
turbine as read from the S7-1200.