Your review about this book

Hello everyone,
I am about to purchase this book
Creating Human Machine Interfaces Using Visual Basic
by Jeff Weigant

Before i spend money on it, I would like to know whether anyone has read this book and whether it is a good starting point for rookies who just know that HMI is Human Machine Interface and nothin' more.
I have done some VB, currently I am writing lader logic programs using RSLogix500 in a AB micrologix PLC and I have RSLinx installed.
Do i need additional software like RSView or ControlLogix?

regards
taknevs

I have done several projects using VB and Micrologix processors. You basically have 4 choices when doing HMI for AB processors.

1. Use a standard HMI such as the panelviews and use supplied software to program them. Cheaper but less functional.

2. Purchase HMI Software such as RSView. This approach gives you the ability to create very functional HMI's and are relatively easy to learn and use. The downside is the price.

3. Use Visual Basic and RSLinx. This approach lets you program an HMI with a wide range of functionality. You would have to use DDE (outdated technology) or OPC. OPC can be a little tough to get a grasp on at first. The downside is that RSLinx Lite will not work. You need RSLinx Gateway or Single Node, they are both a little pricey if you ask me.

4. Use Visual Basic and a third party communication ActiveX or DLL.
This is my favorite approach because the ActiveX or DLL's are fairly easy to program with and you don't have to use Rockwell Software.
Some of these ActiveX's are expensive and some are cheap. Do a search on this forum for them.

Hope this helps.

WonderWare

I have a question along the these same lines. Is VB and WW about the same HMI are their any thing better about one or the other??? I have an option to learn VB programming. My plant currently uses WW Factory Suite. We have about 18 WW stations.

Wonbderware (and all other HMIs) do a lot of the donkey work for you, and make animation easier.

In VB, you dimension a bunch of variables.
In WW, you create a bunch of tags.
Not too different.

In VB, you have to write code for each variable to get its value from the PLC at a specific address. WW is more like a spreadsheet (and can be editted in Excel).

When you go to animate an object, WW will give you a list of all your tags. In VB, you can get a list of your variables, but unless you were smart and gave all your process varaiables a common prefix, you won't know which are I/O variables, and which are not.

And sometimes you forget if this tag goes to the datapoint you think it goes to ("Is PRESSURE_OK the high pressure switch tag, or the permissive that says that I'm at atmospheric and it's OK to open the valve?"). A WW tag has a description field that you can use to augment a failing memory. All VB has is comments embedded in the code. Although again, a good nomenclature system goes a long way.


In VB, you have to write a script to change the properties of an object based on the value of a variable. In WW, just double click on the object, select the property, and reference a tag. Much less chance of a typo. Much easier to debug.

Making something blink is easy in WW. Much less so in VB.

Most of what it comes down to is a matter of time (and time is money is profits, or the lack thereof). VB takes longer to develop in, is harder to maintain (not that WW is a piece of cake, depending on how "script-happy" the application is), and has a steeper learning curve. Someone with minimal experince can walk up to WW and modify a screen in an hour. Even a good VB programmer is going to need a fair amount of time to figure out how the previous programmer set things up, where his calls are, before being able to make the similar changes.

On the other hand, VB is cheaper (especially if you write your own communicaiton driver). So once you've created one application, a second one adds no additional cost (except that I've yet to see two "identical" systems - there's always some difference between them), whereas you at least have to buy a second licence of WW.

Hi Allen,

Have You try use AxtiveX-control MSComm32.ocx in Your WW-Script,
I have try and final result is that every other control as #Comm.Port=4; but #Comm.Output = anyTag or anyContentValue; itself do not work.
No problem I made own ActiveX-control who uses Comm.Output and it works and I do not need eny extra driver for serial ports.
Serial Port is 20 yers old very very simple Interface in PC, why I can't send simple message out with ww without 'Project'?
With VB it works in a minute.

Also I made DDE-connection with my VB.EXE, but MESSAGE-variables
didn't work. After I Installed MSVisualStudio6.0 to PC where WW is,
MESSAGE-variables waked up with same Applications.

For all of Comm.output I have studing MS-Visual Basic and it toke
one week (MS-Visual C++ toke one yer).
In this case I have spend too much time with ww. So pure VB-solutions is economical vs. ww. in this case.

Every time when MicroSoft updates my OP with new.oxc they comes
unknown in InTouch.
I know why, but can PLC-programmer commonly know why?

Finally, for many HMI-Views I like use ww, in other case VB.

Hi Allen,

I have been trying to get my head around Vb/plc5,slc500 applications,i can manage to read or write blocks but i cannot get my head around how you individually access integers in differnt files.Would it be possible for you to explain this to me in more detail.You can post it here or e-mail me @ [email protected].

Knowledge not shared is energy wasted

I purchased this book about two years ago. I became interested in using VB6 after seeing some machines at a semiconductor facility that used VB as an HMI. The company that I worked for at the time used packaged interfaces such as Wonderware. I found that many customers liked the packaged interface but did not like the price.
After purchasing the book I sat down at home on a Saturday morning with a micrologix PLC, and was turning bits on and off, and reading registers within a couple of hours. I think the book is well thought out and is a great starting point. I have now moved on and created much more complex interfaces after getting tips from different sources.