Trends

A Trend graph displays a dynamically changing value graph that tracks a single, dynamic value such as a temperature value, as a curve on the Vision screen.

Trends are displayed in the Project Navigation Window.  The number of Trends and Curves that can be displayed depends on controller model:

• V560/ ERROR: Variable (V570V1040V1210) is undefined.
  Up to 8 Trends, each displaying up to 8 Curves

• V130
  Up to 4 Trends, each displaying up to 2 Curves

Each Curve may be linked to a different register, and can be configured to a different color.

Trends have a default touch property that causes a touched Curve to be brought forward. In the following figure, the Temperature curve is in front.

Touch the Mode button to toggle between:

• Run Mode:
  Shows the Trend being drawn in real-time

• History Mode:
  Stops the Trend, displays History Scroll buttons; touch these to scroll back and forth between different Trend graph sections

V130

Since the V130 does not offer a touch screen, you use the Keypad arrow buttons to enter and navigate through History Mode

Creating a Trend graph

1. Define a Trend:
   Right-click the desired Trend to open and set Trend Properties.

   

   Property	Function
   Name	Assign a unique name to the Trend.
   Sampling Interval	Defines how often the Trend draws Curves, resolution = deciseconds (0.1.)
   History Samples	Total number of samples that may be stored in History for ALL Trends is 32000.  The minimum number that may be allocated to a Trend is 50. To view the total History Allocation, right-click Trends in the Project Navigation Window
   Run / Stop MB	0= Stop 1=Run Status rises from 0 to 1: The PLC begins to draw the Trend Curves The History is initialized 'Run' is displayed at the bottom of the graph Falls 1 to 0 Trend freezes Under can press Mode button to enter History and scroll through Trend 'Stop' is displayed at the bottom of the graph
   Trend Description	This parameter is intended for future feature support. It has no influence on the Trend graph.

    

2. Define Curves
   Right-click the desired Curve to open and set Curve Properties.

   

   Property	Function
   Name	Assign a unique name to the Curve for display on the HMI screen. You can also use the String Library. The string you select will be displayed as the Curve name on the HMI screen; however, note that the string you select will not appear on the Project Navigation tree.
   Data Operand	This is the value represented by the Curve
   Y Min, Y Max	These define the axis range for that Curve. Note that you can also set a decimal value.

Once you configure a Trend and at least a single Curve, you can place the graph in different HMI displays and set specific properties for the Trend in that display, such as the Trend background color and Curve colors.

3. Place a Trend Graph in an HMI Display

1. Click the Trend icon on the HMI toolbar, and then drag the cursor across the screen to draw the Trend.

   

2. Release the mouse button, and define the Trend Variable properties.  
    

   Note ♦

   Under Links, note that the Link MI shows which Curve is currently forward V570 1= Curve 1, 2=Curve 2, etc. Therefore when the MI contains 3, Curve number 3 will be forward V130:2=Curve 2. 1, or any other value causes Curve 1 to be forward

    

    

    

   Tab	Property	Function
   Appearance	Points to Display	Sets the number of actual points that will be shown on the screen at any one time
   	Number of X ticks, Y ticks	Set the number of gradations on the axes
   	History scroll mode	Sets the paging size for History view Note that@@@@@ is half screen quarter screen
   	Draw lines between points	If this is not selected, the Curves will be drawn as a series of points
   	X Axis Color	Note that the Y Axis color always changes to match the Curve than is in front
   	Buttons Color	Sets the color for the Mode, Grid, and History Scroll buttons
   	Grid Color	Set the color for the background Grid
   	Change current Curve on Touch	Checked by default. Curves have a built-in touch property that causes the touched Curve to be brought forward.
   Curves	Color	Click to set a color
   	Hide Curve	if you assign a Hide Curve MB, turn it ON to hide the Curve.

    

   Note that the Link MI determines which curve is forward. In the case of the V570, touching the curve writes the curve value to the MI, bringing the touched curve forward.

Trend from SD

Start and stop the Trend as shown below.

To learn more about Trends, check Trends - Color Vision.vlp in the Help> Examples.