Hi:

This is my first post here, so I'll try to state this briefly:

Existing system: Automated Storage/Retrieval machine in a production warehouse, controlled by SLC5/03. Operator station has a PC running a custom application to issue Store and Retrieve commands to the machine (connected via RSLinx using serial DF1). The commands come into the PC as ASCII strings from a VAX work order system via the PC serial port. The custom app then parses the string, puts the appropriate data into the SLC, and sets a bit high for "Execute". Meanwhile, the PC also hosts a couple of terminal emulation sessions so operators can interact with VAX and IBM systems for work order processing and inventory update, etc.

(Whew, that's a new definition of "brief" that hadn't occurred to me before...)

Assignment: Replace the old clunker PCs running NT 4.0 with nifty new panel PC's (XP Pro), AND while we're at it, rewrite the operator application using RSView32 (client's request). The idea would be to wrap everything up into one single app, including embedding the terminal sessions (I've located an ActiveX terminal emulator). I haven't used RSView32 before, but so far I've learned that neither RSView32 or RSLinx can really speak plain old ASCII on a serial port, and this really is the heart of the whole thing.

OK, if you've made it this far, here's the question:

If I'm gonna have to write VB (VBA?) code to handle the VAX serial communications and string parsing, and if I'm using ActiveX components for the terminal emulation, is RSView32 really bringing anything to the party? Couldn't I just write this whole thing in VB? Or am I asking for trouble on the SLC side by using VB with RSLinx? I have RSLinx Single Node, and assume I'd use the DDE/OPC mechanism to communicate with the SLC.

Thanks in advance,

--Mike Gibbons
Engineered Industrial Systems

Mike just some thoguhts on point I hope.

1. Given that the majority of the automation world is headed in the direction of OPC if startting a new app I'd use OPC over DDE. The overhead and learning curve is slower with OPC than DDE {my opinion} but the final return and flexability is bette with OPC.

2. RSlinx works great with VB and there are some commands not available in VBA that you can use in full VB.

3. Rsview while limited to VBA does give you certain speed advantages in screen creation and interfacing to the slc.

Others with more experience are sure to respond and agree/disagree with me.

First of all there is no such thing as too much information when posting. The more information you give us the more we can give you in return.

Just a few questions.

Do you see having to integrate other brands into this?

Are you more familiar with VB or RsView?

When you say VB are you talking about the older VB or VB.Net?

Do you mean other PLC brands, or other products in general? Doesn't really matter, because in either case the answer is no. The scope of this project is simply upgrade of the existing hardware with new software. Of course, this really means "no", until the client says, "by the way, can you..."

I'm more familiar with VB than RSView, and it's the older VB6, not .NET

--Mike

My problem with the old VB6 is aren't you developing code for a software platform that is in the process of being replaced?

Yes, that's a very good point. One of the objectives here is to make this system last for a while-- it's >10 years old, and there's a mechanical rehab going on in parallel with this.

Actually, I have a copy of VB.NET around here somewhere that I've never installed or played with. I suppose I could just as easily try this in .NET, but would I be in for more of a science project using it with RSLogix, or are the issues all the same? Or am I just imagining "issues" that aren't really there?

From what i have seen and read for those that have used RSlinx with VB6 and then go to .net there is a learning curve. But if this is your first vb and linx application I'd start with .net.

Yep, it looks like that's the direction this is heading. Now for the next obvious question: do you know of any references for example code or tutorials on VB.NET/RSLinx applications? The thought of going on the Rockwell site to try and dig up useful information is making my head hurt...

Check the HMI Sample code under the downloads section. Techjunki also has a nice sample of OPC in VB.

BobLfoot and TWControls:

Thanks for your replies. I've been researching, downloading and reading like crazy to figure out which direction to go, so I can have a talk with the client soon. I'll post again with an update as this thing progresses.

--Mike