Siemens S7-1200 - Reading and Displaying Controller Data

Web server
11.6 User-defined Web pages
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
647
The next part of th
e page displays atmospheric
conditions at the wind turbine. I/O at the turbine
site 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.
The following sections allow for
manual control of the turbine, overriding the normal
automatic control by the S7-1200. These types are as follows:
•
Manual override: enables manual override
of the turbine. The STEP 7 user program
requires that the manual override setting be
true before enabling the use of any of the
manual settings for turbine speed, or yaw or
pitch.
•
Yaw override: enables manual override of
the yaw s
etting, and a manual setting for the
yaw. The STEP 7 user program requires
that both manual override and yaw override
be true in order to apply the yaw setting.
•
Pitch override: enables manual override of
the pitch of the blades. The STEP 7 user
program requires that both manual override
and pitch override be true in order to apply
the blade pitch setting.
The HTML page includes a submit button to
post the override settings to the controller.
The braking user input field provides a manual
setting for a braking percentage. The STEP 7
user program does not require manual override
to accept a braking value.
In addition, the HTML page uses an AWP command to write the special variable (Page 633)
that contains the user ID of the user that is accessing the page to a tag in the PLC tag table.
11.6.8.2
Reading and displaying controller data
The "Remote Wind Turbine Monitor" HTML page uses numerous AWP commands for
reading data from the controller (Page 629) and displaying it on the page. For example,
consider the HTML code for displaying the power output as shown in this portion of the
example Web page: