After you select the New Block command, the mouse pointer will look like "+" (a cross) that you can use to mark the borders of the new block. To do it, you should hold down the left mouse button and drag the rectangle to make it the necessary size. You can move the block over the tab using either the mouse or the arrow keys on the keyboard. You can use the keyboard to move the block as accurately as possible.
After you finish marking the borders of the visualization block, you will see the Visualization Block Parameters dialog box (fig.1). First, you should select the OPC tag the indicator will be displayed for. Depending on the tag data type, the list of available indicator types will be formed.
Fig.1. OPC tag selection
To select a tag, you should switch to the "OPC tag" tab and click the "Select a tag from the server" button. After that you will see the OPC Tag Selection dialog box (fig.2).
Fig.2. Server and tag selection
Computer - you can specify the name or the IP address of the remote computer. If you need to connect to the server on the local computer, specify LOCALHOST as the computer name. After you enter the computer name, click the "Update" button to get the list of available OPC servers. If the program cannot retrieve the list of servers, the following reasons are possible:
•The program was run by a user who has no permissions to connect to remote computer;
•OPC Core Components Redistributable from www.opcfoundation.org are not installed on the local and remote computers
Servers - the list contains the list of available OPC servers on the specified computer.
Info - the group shows brief information about the selected OPC server.
•Server - the field shows the program ID (program name).
•Description - the fields shows the brief description of the server.
•DA support - the fields shows the supported DA.
•Vendor - the field shows the name of the vendor.
Connect - the button connects the module to the server and tag (if there are any on the server) appear in the "Tags" list after that. It is also possible to connect to the server with a double click on the server selected in the "Servers" list.
Tag selection mode - the list allows you to select one of the modes for selecting tags. Two modes are available:
1.Automatically retrieve tag names from the server - the program automatically retrieves the list of tags and their parameters from the server. Not all servers support this feature;
2.Manual mode - you have to specify the names of tags manually in this mode. You should use this method if the server does not allow OPC clients to retrieve the list of available tags.
Filter - it allows you to select only tags meeting the specified condition (by name or by data type) from those available on the server. This feature is convenient when there are a lot of tags on the server.
Tags - the list contains tags available on the selected server.
Info - the group shows information about the selected tag.
•ID - the column shows the tag identifier;
•Description - the column shows the brief description of the tag;
•Type - the column shows the tag type.
•Value - the column shows the tag value.
Fig. 3. Tag properties in the manual mode.
Tag - you have to specify the tag name, including the full path to it if there is any.
Server connection parameters
After you select a tag in the manual or automatic mode, click the "OK" button and the information about the selected tag will appear in the Visualization Block Parameters dialog box (fig.1).
After that you should check the connection to the OPC server. To do it, switch to the "Connection" tab (fig.4)
Fig. 4. Server connection parameters.
Active - if this option is enabled, the value of the tag will be retrieved from the OPC server.
Update every - the program will retrieve the values from the OPC server at the specified period.
Force read - if this option is enabled, the program will force read an OPC tag value from the OPC server. Otherwise the program will wait for notifications about a value update from the OPC server. This read mode can be useful with some remote OPC servers.
Dead band (%) - the field contains the value of the dead band in percent. If the value of the tag changes within the dead band, the program will consider it unchanged and the value of the tag will not be shown. The default is 0 percent.
After you select the tag, you should configure the display parameters for this tag. Depending on the tag data type, certain indicators will be available. To configure the display parameters, you should select the "Display Parameters" tab (fig.5).
Fig. 5. Display parameters.
Every visualization block has several elements (fig.6). You can configure every element in the visualization block after you select the corresponding item from the "Element" drop-down list. You can show or hide each of the elements.
Fig. 6. Visualization block.
You can use the display parameters to specify the exact position of the visualization block and its size. To do it, you should select "Window" from the "Element" list (fig.7).
Fig. 7. Visualization block window parameters.
You can also specify the background color for the selected block and its alignment:
1.None - the block will be placed according to the user-defined position. The block size does not change;
2.Left, Right, Top, Bottom - the block will be placed along one of the specified sides. Besides, the block will be resized to fit the tab size. For example, if you select "Left", the block will always placed along the left size of the tab and the height of the block will correspond to the height of the tab;
3.Client - the block will occupy the entire area of the tab.
Visualization block element description
1.Title - the program allows you to specify any text as the title of a block and to format it;
2.Status indicator - it shows the status of the connection to the OPC server. The green indicator shows that the connection to the server is active, while the red one shows that the connection has been broken;
3.Indicator - the value of the tag can be displayed with the help of various indicators. The program offers more than 20 types of various indicators. Each of them has its own set of display parameters that are displayed as a tree in the fig.5. You can preview changes in this tree of parameters in the preview window to the right from the tree of parameters. Data types the selected indicator can be used for are shown under the preview window;
4.Frame - the frame allows you to visually limit the block size. When the frame is enabled, you can also resize the block with the help of the mouse;
5.Current OPC tag value - some indicators are graphical ones it is difficult to tell the precise value of the tag from. This element allows you to display the precise value in addition to the value on the indicator;
6.Minimum and maximum values for the OPC tag - this parameter allows you to specify one or several conditions (fig.8) that will serve as a limit for the acceptable values of the tag. If the value exceeds the specified limit, the program will show a warning.
Fig. 8. Element parameters.
You can do the following for every element in a visualization block (fig.9):
•Show or hide the element with the help of the "Show" option;
•Specify the type, size and color of the font using the standard dialog box opened with a click on the "Font" button;
•Specify the alignment inside this element using the "Alignment" drop-down list;
•Specify the frame color;
•Specify the background color.
You can specify the list of conditions for the "Value", "Minimum" and "Maximum" elements (fig.8). If they are met, the program will display warnings and play the specified sound. To add a warning, select the corresponding element in the list and click the "Plus" button. After that you will see the dialog box where you should specify the necessary parameters (fig.9). Other buttons next to it are used for the following operations (left to right):
1.add a new warning;
2.delete the selected warning;
3.delete all warnings;
4.edit the selected warning;
5.move the selected warning one position up;
6.move the selected warning one position down.
Fig. 9. Warning parameters.
You can configure the following parameters in the Warning Parameters dialog box:
1.The condition that will trigger it. While specifying the conditions, keep in mind that some conditions cannot be used for some data types. For example, string values can be checked only if they are equal;
2.Deferred execution. If this option is enabled then the program will wait the specified time and if the value will return to the normal state within this interval the enabled actions will not be executed.
1.Play sound (fig. 10) - when this action is active the selected sound will be played when the condition is true. Once - the sound will be played only once when the condition state will be changed from false to true. Continually - the sound will be played until the value will return to the normal state.
Fig. 10. Sound settings.
2.Send email - an email will be sent to the specified address when the condition state will be changed from false to true. The subject and body of the email can be defined below the address. You may use special placeholders like %VALUE% in the subject or body. When the program will send the email all these placeholders will be replaced with their values:
%FULL-DATE% - date and time
%DATE% - date
%TIME% - time
%VALUE% - the current value
The connection parameters with an email server you may define in the Program settings.
Fig. 11. Email settings.
3.Schedule - this tab allows to define a schedule when this condition will be active. You may select necessary days of week or/and the time of the day. If the time is not defined then the condition is active 24 hours per day.
Fig. 12. Schedule.
This function allows to scale the value using simple math functions (fig. 13). The scaled value will be visible in the block and will be used later (e.g. in the warnings). Of course, you may use the scale function for the numerical values only.
Fig. 13. Scale.
The scripts allows to extend the standard functionality (fig. 14, 15). For example, they allow to transform the opc tag value as you want. The build-in scripting engine uses BasicScript. This is very simple implementation of the Basic programming language.
The BasicScript structure is:
dim i, j = 0 // var section
function f1() // procedures and function
end function //
// main procedure that will be executed.
for i = 0 to 10
Additionally, the scripting engine has two special functions:
GetValue(Name) - this function returns the current value from a block with the "Name" OPC tag.
SetValue(Name, Value) - this function sets a new value in a block with the "Name" OPC tag.
The Name argument should match the name from the "Tag info - Name" fields (fig. 1).
' Case operator demo
dim val1, val2, name1, name2
name1 = "ThisBlockOpcTagName"
name2 = "AnotherBlockOpcTagName"
val1 = GetValue(name1)
select case val1
case 1: val2 = "new value 1"
case 2..10: val2 = "new value 2"
case else: val2 = "new value 3"
Fig. 14. Scripts.
Fig. 15. Script.
Click the "OK" button to save the warning parameters. The warning will appear in the list after that.
To save the visualization block parameters, click the "OK" button in the Visualization Block Parameters dialog box. All changes will be applied after that.