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Built-in functions of InduSoft Web Studio Mobile Access in Service Pack 3

Many but not all of InduSoft Web Studio’s built-in functions are supported in project screens. To see if a specific function is supported, please refer to the documentation for that function. The function will be marked either “Supported”, “Not Supported”, or “Executed on Server”, and there might be additional notes describing how the function is executed in Mobile Access.

Functions that are marked “Executed on Server” are executed via remote procedure call (RPC) on the project runtime server. While these functions are supported, you should avoid using a large number of them in any project screens that you include in Mobile Access. The extra communication required between server and client can affect run-time performance.

Also, please note that because Database/ERP functions are executed on the server, they affect server tags (i.e., tags with Server scope) rather than local tags (i.e., tags with Local scope), and that might result in unexpected behavior when multiple clients try to execute the functions at the same time. As such, you should avoid specifying optional parameters that take tag names — for example, if you call the function DBCursorOpen, do not specify the parameters optStrTags and optStrTagError.

 

VBScript in Studio Mobile Access

Most VBScript interfaces — including the Graphics Script, the Screen Script, and Command animations on screen objects — are supported in project screens in Mobile Access. All regular VBScript functions, commands, and syntax are fully supported. However, InduSoft Web Studio’s built-in functions — which can be called in VBScript by prefacing them with $ — and other features have the following limitations:

Built-in functions

Many but not all of InduSoft Web Studio’s built-in functions are supported at this time.

Dialog boxes in the Graphics Script

Functions that display dialog boxes in the Mobile Access web interface cannot be called from the Graphics Script. They can be called from the Screen Script or Command animations. Also, displaying a dialog box will cause the web interface to stop updating, until the user closes the dialog box.

Functions that display dialog boxes include the VBScript function MsgBox and the IWS built-in function Logon.

Calling procedures declared in the Graphics Script

Normally, procedures that have been declared in the Graphics Script can be called from other VBScript interfaces using the syntax Graphics.procedurename. This feature is not supported in Mobile Access. Any procedures that you want to call like this should be declared in Global Procedures.

System tags GroupCNFHiLevel and GroupCNFHiLevel

The pre-defined system tags GroupCNFHiLevel and GroupCNFHiLevel are not supported in Mobile Access. In fact, these tags have been deprecated; if you want to check the security levels to which the user has access, use the function CheckSecurityLevel instead.

Tags

The VBScript compiler for Mobile Access is stricter than the one used elsewhere in InduSoft Web Studio. It will not accept references to unsupported tag fields. For example, if you try to use $MyString->B0 in VBScript anywhere else in InduSoft Web Studio, the compiler will accept the reference and simply return 0 or some other invalid value. On Mobile Access, however, you will receive a run-time error because B0 is not supported on String tags. You can check for such errors in the activity log.

Tag changes in the Event Logger

When a project tag is changed using VBScript in Mobile Access, that change will be logged in the Event Logger with the client’s IP address instead of its host name.

Date formats and time zones

While the server and clients may have their respective system times, Mobile Access always uses the server’s date format and time zone settings when it opens project screens. In the current release, it is not possible for the server and clients to have different settings, so you should not try to view project screens on clients with different settings as that might result in unexpected behavior during run time. (It is okay to use the Alarm, Process Values, and Trend controls in the web interface, because they do not include any VBScript that might be affected by this limitation.)

You can change the time zone setting on your client to match the server, but if that is not practical and you must view your project screens while in a different time zone, you should use Secure Viewer or Web Thin Client instead of Mobile Access.

Boolean tags

Mobile Access does not support the legacy method for handling Boolean tags (i.e., project tags of Boolean type) in VBScript. Boolean tags are always handled as if they have a numerical value of -1 for TRUE, to ensure compatibility with Boolean variables in VBScript. Editing your project file to change the property VBBoolean will not override this.

Statement continuation with comments

In VBScript, you can use an underscore character to indicate that a statement is continued to the next line. Programmers often do this to make a long statement easier to read. For example:

MyArray = Array("FIRST_NAME", _
                "LAST_NAME", _
                "ADDRESS")

Without the underscore character, the end of the line would also be the end of the statement.

The VBScript compiler in Mobile Access supports continuing a statement like this, except for the following limitation: in MsgBox statements and function calls, you cannot insert a comment after an underscore character. For example:

MyVar = MsgBox("Hello World!", _ 'This is a comment
               65, _ 'This is another comment
               "MsgBox Example")

This code would not be accepted by the VBScript compiler in Mobile Access, and the resulting compiler error could prevent a project screen from opening at all.

 

Important features not supported

Mobile Access supports only the features listed above and with the limitations mentioned. Among the features not supported, the following ones are most commonly used:

Windows Embedded

The Mobile Access Runtime software cannot be installed on Windows Embedded, and Mobile Access cannot be configured in projects that are set to run on Windows Embedded target systems.

Selecting from a list of users to log on

The Mobile Access Logon screen does not support selecting from a list of users. The user must know and type in their user name.

Opening multiple screens or screen groups

You cannot open multiple screens or screen groups in the Mobile Access web interface. If you need to display a supplemental screen of some kind, try one of the following:

  • Configure a group of objects to act as a supplemental screen, and then apply the Visibility animation to that group in order to show/hide it; or
  • Call a function to show an appropriate dialog box. Such functions include the VBScript functions MsgBox and InputBox and the IWS built-in function ShowMessageBox.

Tip: Avoid creating a script that both shows a dialog box and opens or closes a project screen. The Mobile Access web interface can display only one screen at a time, and opening a new screen will automatically close the previous one. Depending on the order of execution, this can lead to unexpected behavior such as a dialog box being orphaned or not being shown at all.

Data objects

The Alarm/Event Control object, the Trend Control object, and the Grid object are not supported in project screens in Mobile Access. For alarms and trends, you can use the Alarm and Trend controls that are native to Mobile Access. For grids, you can use the database interface to populate project tags with the appropriate data, and then display the tag values in your own, custom-made grid.

Embedded bitmaps

Embedded bitmaps are not supported in project screens in Mobile Access. If you paste bitmaps into your screens, make sure that they are saved in separate files.

Image formats

Support for certain image formats varies from browser to browser. If you use an unsupported image in your project screen, the browser will not be able to render that image when you view the screen in Mobile Access. For example, Internet Explorer can render Windows Metafiles, but Google Chrome cannot.

For the best performance across all browsers, try to use “web-compatible” image formats such as GIF, JPG, and PNG wherever possible.

Additional options for Driver and OPC communication

Some additional options for Driver and OPC communication are not supported in Mobile Access. First, in the project settings, the option Send last state is not supported. Mobile Access automatically uses the option Send every state, with a fixed buffer size of 5.

Second, in OPC communication worksheets, for the Scan setting on each tag configured in a worksheet, the option Screen (to scan the tag only while a screen that uses the tag is open) is not supported. Projects viewed in Mobile Access should use the option Always (to always scan the tag while the worksheet is enabled). As an alternative, you can configure an entire communication worksheet to be enabled only while a screen is open.

Compressing files for faster downloads

In projects that are accessed by Secure Viewer and Web Thin Client, you can choose to compress the screen files to make them faster to download over slow connections. (The option Enable File Compression is located on the Web tab of the project settings.) This feature is not supported in Mobile Access. If you try to view a project screen that has been compressed like this, the screen might behave unexpectedly and you might see messages in the activity log that say tags or objects do not exist.

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