Professional OPC
Development Tools


Online Forums

Technical support is provided through Support Forums below. Anybody can view them; you need to Register/Login to our site (see links in upper right corner) in order to Post questions. You do not have to be a licensed user of our product.

Please read Rules for forum posts before reporting your issue or asking a question. OPC Labs team is actively monitoring the forums, and replies as soon as possible. Various technical information can also be found in our Knowledge Base. For your convenience, we have also assembled a Frequently Asked Questions page.

Do not use the Contact page for technical issues.

Excel Integration (writing to an OPC-UA tag)

13 Nov 2017 06:47 #5651 by support
For record, here is the related piece of documentation: .

Ad 1. The feature is no less supported than anything else in the product. That is, it should work as designed, and if it doesn't, we will attempt to address it. The issue here is what *as designed* is. The functions in Excel are, well, functions. They are not supposed to have side effects, and consequently, Excel is basically free to evaluate (and re-evaluate) them at just about any time. The "topic write" feature of the RTD server does have an important side effect, and that's what in some way collides with the Excel. So, the feature should work, in the sense that every time Excel evaluates the RTD function that specifies "toipc write", the OPC write should occur. Whether that is what you need or can live with, is up to you.

Ad 2. No, we are not planning any improvements in this area (because currently we do not know about any better way). If the "topic write" does not work the way you want, you can do the OPC writes with QuickOPC in a different way, though. You can use VBA and call QuickOPC methods to do the write. We have examples for that as well. To find them, 1) make sure you install QuickOPC including "COM development", and 2) under the product folder, look for ExamplesNet\VBA\Excel\UAReadAndWriteValue.xls.

Ad 3. Please be more specific. Are you asking about possibility to handle errors that occur during "toipc write" with RTD server yourself?

Best regards

Please Log in or Create an account to join the conversation.

13 Nov 2017 06:34 #5650 by support
From: D.
Sent: Thursday, November 09, 2017 3:34 PM
To: Z.
Subject: RE: OPC Labs Contact Form - Excel Integration

[...] I'm trying to bi-directionally synchronize certain cells in multiple spreadsheets across an enterprise.
[...] I've been trying to understand the functionality of the Excel host writing back to an OPC-UA tag value with mixed results. This is rather pivotal to my intended use of your product. Further reading in the docs reveals that this is an unsupported feature.
1. Is my interpretation of the docs correct?
2. If so, is your development team working on a more robust/supportable feature? Established release timeline?
3. Can you help me understand better the failure modes, so I might catch and handle those errors in my coding/scripting?

Please Log in or Create an account to join the conversation.

Moderators: support
Time to create page: 0.174 seconds