HMI Scripting Languages

  • Thread starter Shahid Waqas Chaudhry
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Shahid Waqas Chaudhry

Dear List, Most of the HMIs use VBA (or some other spin off of Visual Basic) as their scripting tool. eg: RSView, Iconics, Intouch, Intellutions etc. SIEMENS, however, offers both of these in two differnt packages: In their HMI/Panel Designer they use VBA but in the Flagship HMI WinCC they use C-Script (or as they call it API-Script), which brings me to my questions: 1) What are the advantages of using VBA over C-Script or vice versa? 2) How come SIEMENS adopted C instead of the un-official (or is it semi-official) VBA for its scripting language? 3) What are the limitations of using VBA and C-Script. 4) What are the future trends towards HMI scripting: would we be getting JScript or some other java based scripting soon. Shahid Chaudhry [email protected]
 
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Glass, Philip

I think if any scripting language were to become the de facto standard, it would have to be VBA for it's simplicity and diversity. After all, we're only talking about HMI scripting. Typically you'd never have a need for low-level programming capabilities. Think about the typical usage of the HMI for a second. It's used mainly for monitoring and setpoint entry to a control device. You'll probably have some error-checking for operator entry points and perhaps some kind of algorithm for alarm or report generation. Nothing fancy here. If you haven't already used VBA extensively in MS Excel, then you're probably taking far too long to complete your tasks... Point being, there's really no need for a low-level programming language in an HMI and VB/VBA is widely accepted as the programming tool of choice for scripting. If you do have a need for some low-level functions, you could probably get by issuing an API call. Philip L. Glass [email protected]
 
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I can answer part of your question: One of the advantages of using VB over C++ or some other language is the large availability of VB programmers, and another is the speed with which one can develop applications. One of the limitations of VB is latency; i.e. it tends to be a bit slower, in some cases, than C++ and other languages. jfv John F. Vales Director of Technology Wes-tech Automation, Inc. [email protected]
 
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Shahid Waqas Chaudhry

&lt;Snip> > Point being, there's really no need for a low-level programming language in > an HMI and VB/VBA is widely accepted as the programming tool of choice for > scripting. If you do have a need for some low-level functions, you could > probably get by issuing an API call. &lt;/Snip> Sometime there does arise need for extensive scripting. Most (read all) of my client want the maximum functionality from the HMI without paying more money than for the most basic HMI configuration. To accomodate them, I mostly rely on using the scripting language. e.g. One of my client wanted to have a batch management system without dishing out the money for the proper HMI add-on. I wrote the whole algorithm in C-Script (was using WinCC) and the system runs just as well as the Add-on package. Getting on the use of API functionality is a bit tricky. Most of the programmer who use VB/VBA use it for the ease of it (note the word ease and not power) and the short development time. The point I want to make is that the API usage is considered an advanced topic no matter how we look at the definition. Therefore, using API functions, we nullify the advantages of VB/VBA as an easy language. <Snip> Think about the typical usage of the HMI for a second. It's used mainly for monitoring and setpoint entry to a control device. You'll probably have some error-checking for operator entry points and perhaps some kind of algorithm for alarm or report generation. Nothing fancy here. </Snip> Most of these features are now standard part of any decent HMI package.
 
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