WE: Web Trends

The Web Server Toolbox offers two different types of Trend graph widgets:

• Live Trend.
  This displays a running variable integer value as a curve on a Trend graph. You may define up to 4 curves.

• Trend (Data Sampler)
  This is similar to the HMI Trend. It is a graphical representation of a Data Sample.

Live Trend

To configure a Live Trend Widget:

1. Click the Live Trend widget in the Toolbox, move your cursor to the display, and drag it to define the borders of the graph.
   
   

2. Define the Trend Properties:
   - Click the Live Web Trend Curves List collection to open the Curves Configuration.
   - Link the tags that feed the Curves.
   - You can select a color for each Curve, define minimum and maximum values, and set the number format.

Trend (Data Sampler)

To implement a Trend graph, you must:

• Define a Data Sampler that contains at least one Feed.
  Each feed will be represented as a curve on the Trend graph.

  Data sampling enables you to record data, such as output values, at fixed intervals into files on an SD card. A Data Sample can contain a number of feeds.You can define multiple Data Samples.

  You can also represent Data Samples as Trend graphs on the HMI screen.

  Note that when you create a Data Sample, UniLogic creates a struct to enable you to control its functions.

  Property Name	Definition
  Start/End Sampling	Turn ON to begin a data recording session. Turn OFF to stop the session, close the file, and save it to SD card. The PLC saves the file with a timestamp. The timestamp provides the date and time that the file closed (bit=OFF).
  Pause Sampling	Turn ON to suspend the session, without closing the file. Turn Off to resume sampling.
  Force Sample	Use this to sample data without relation to the Sampling Interval. Reset by the OS.
  Clear Log	Turn ON to clear all of the data from the current session.
  Status	0 = No Error -1 = SD card not found -2 = Reserved for internal use -3 = Save File Error (File name may contain illegal characters)
  Sampling Interval	Read-only. This parameter is defined in the Data Sampler Properties.
  Missed Sample Bit	Turns ON if no Data Sample has been made during 2 Sampling Interval times. Reset by user.
  Missed Sample Counter	Increments each time the Missed Sample Bit turns ON.
  Samples Count	Read-only. This is the number of times the data is sampled during the session.
  User Comment 1	The user can add comments (strings), such as Batch #; these are saved as part of the data file on the SD card.
  User Comment 2

  Defining a Data Sample

  1. Open Data Sampling from the Solution Explorer tree.

  2. Click Add New Data Sample.

     

  3. Define the Properties for this Data Sampler.

     Property Name	Definition
     Folder Name	Click the field to assign a folder name. The application will create a folder of this name on the SD card to store the Data Sampler files.
     Name	This is the reference name of the Data Sampler object.
     Sampling Interval	This determines the time between data samples.

  4. Add data Feeds: click Add New Feed, and then define the Feed Data Source Tag.
     Note that you can change the default Feed Name by clicking the field and editing it.

     

  Sampling Data

  Use the members of the Data Sampler Struct: Start/End Sampling, Pause Sampling, and Force Sampling tags in your Ladder to control the sampling process.

  In the image below, a Data Sampler is displayed as a Trend graph. The HMI buttons under the Trend are linked to the Data Sampler struct.

  

• Place and configure a Trend widget on a web page.

• In your application, use the Data Tags within the Sampler to start, end, and pause the data feeds.

Configuring a Trend Widget

1. Click a Trend widget in the Toolbox, move your cursor to the page, and drag it to define the borders of the graph.
   
   
    
2. Define the Trend Properties:

1. Click the Data Sampler field to select a Data Sampler to supply data Feeds for the Trend Curves.

2. Click the Trend Curves List collection; the Curves Configuration opens.
   Note that the curve Names are the names of the Data Feeds within the linked Data Sampler. You can edit a Feed name in the Data Sampler, but cannot edit them in the Curve Configuration.
   You can select a color for each Curve, and define minimum and maximum values.

When you download the application to the controller, the Trend widget contains elements and buttons that control the display of the Trend graph.

The table below relates to the elements in the widget.

In the image below, a Data Sampler is displayed as a Trend graph. The HMI buttons under the Trend are linked to the Data Sampler struct.

Related Topics

Web Server

Web Page Editor

WE: Hyperlinks

WE: Web Actions

WE: Web Server Passwords

Data Tables

Creating a Data Table

Entering/Editing Data Table Values

Data Sampling

HE: Data Table Widget