Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: plcnut on April 18, 2013, 08:00:04 AM
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Is there any way we can get a bigger data buffer for the STREAMIN and STREAMOUT instructions?
With the power of TCP connections and custom protocols, I have found that the buffer size has become a major obstacle.
If this is a big issue for you to deal with, then I will try to restructure my thinking to work with the smaller buffer size.
Thanks for a super little piece of equipment!
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Can I link multiple STREAMIN instructions together to be able to receive a larger data stream?
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Sorry to not respond sooner...this got buried somehow. ???
No way to do larger buffers now. Not sure about the future. We have developed a flash file system for Do-more which eventually we want to get installed and supported with appropriate utilities. I'm sure that we will do some things to expand the length of data that can be moved once we introduce it.
...however...
Every bit of comm I do to and from the Do-more controller is done with 1K buffers, and I have never developed comm for anything where I used more than that. Where I am moving large blocks of memory, it is always handled as multiple smaller chunks. Even streaming protocols like HTTP that are moving large files are still chunking them on and off the wire.
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I have a couple of things I'm working on right now:
One. Using the PLC to serve up a webpage and passing data back via GET. (working in experimental mode right now)
Two. Passing larger blocks of data via GET with the PLC being the client. (in actual use currently) I'm hoping to be able to pass larger amounts of data while maintaining data integrity.
Based on your comments, I think I need to restructure the way I deal with data passing. Web based programming is all new to me, and I'm learning of more and more ways to do things. Now I just have to figure out the best way to do what needs done based on the limitations of the devices being used.
Thanks again.
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So far the linking of STREAM commands is working great! The DoMore makes a great little server that can display/manipulate any PLC data I want.
I am currently displaying a home screen with links to 5 other pages that are all stored in the DoMore. I set up a user data block of strings(each containing html and javascript code), and use indexing to STREAM each of them out as webpages ;D
Won't be long and a person wont need a dedicated HMI...
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So far the linking of STREAM commands is working great! The DoMore makes a great little server that can display/manipulate any PLC data I want.
I am currently displaying a home screen with links to 5 other pages that are all stored in the DoMore. I set up a user data block of strings(each containing html and javascript code), and use indexing to STREAM each of them out as webpages ;D
Won't be long and a person wont need a dedicated HMI...
Extremely cool! Hats off!