Logix "First scan after download"?

Join Date
Feb 2009
Location
Illinois
Posts
32
In Studio5000, is there a way the PLC program can detect that has just been downloaded? In my circumstance, data stored in the program contains positional information unique to each installation. If a program is downloaded or re-downloaded to the PLC, then the data is considered invalid, requiring the user to interact. The data is considered invalid because it could be old.

Here are my current ideas:
- Store a copy of the data on the flash card, PLC checking for differences at power up.
- Store the data, or a maybe some kind of checksum, on the associated PV7 using some kind of recipe function, PLC checking periodically.
- Since the data is associated with servo motion, maybe there is some memory in a servo drive I can "store" data in, PLC checking periodically (K5500).

But, I'd rather keep it simple and just make the data "invalid" after a download. Any ideas?
 
I've done something similar in a system that had more than one PLC (each PLC checked to see if the others had gone into program mode, then when any transitioned back to run the others "told them" they had been in program mode.)
Could you just use the first pass bit to initialize values?
 
I've done something similar in a system that had more than one PLC (each PLC checked to see if the others had gone into program mode, then when any transitioned back to run the others "told them" they had been in program mode.)
Could you just use the first pass bit to initialize values?

Ah, use PLC's to check each on each other. Nice.

The first pass bit would initialize on each power cycle, not quite what I'm looking for.

Thanks for the idea.
 
In Studio5000, is there a way the PLC program can detect that has just been downloaded? (K5500).

No.

You could use the CF/SD memory to load stored data or an entire project.

An entire stored project will be loaded at each power-up if configured as such within the application's Controller Properties.

Data stored as a 'Recipe' could be programmatically loaded into the CPU, however, you would most likely need to use the S:FS (First Scan Bit) in order to trigger the 'Recipe Read' logic hence this would happen at each power-up and after each CPU download.

For Logix CF/SD 'Recipe' handling refer to Page 34 of http://literature.rockwellautomation.com/idc/groups/literature/documents/ap/logix-ap007_-en-p.pdf
 
In Studio5000, is there a way the PLC program can detect that has just been downloaded? In my circumstance, data stored in the program contains positional information unique to each installation. If a program is downloaded or re-downloaded to the PLC, then the data is considered invalid, requiring the user to interact. The data is considered invalid because it could be old.

Here are my current ideas:
- Store a copy of the data on the flash card, PLC checking for differences at power up.
- Store the data, or a maybe some kind of checksum, on the associated PV7 using some kind of recipe function, PLC checking periodically.
- Since the data is associated with servo motion, maybe there is some memory in a servo drive I can "store" data in, PLC checking periodically (K5500).

But, I'd rather keep it simple and just make the data "invalid" after a download. Any ideas?

In the GSV "Controller" object, there is an "Audit Value" attribute. This will enable you to detect that the program has been downloaded, and act accordingly....

2017-06-22_192929.jpg
 
In the GSV "Controller" object, there is an "Audit Value" attribute. This will enable you to detect that the program has been downloaded, and act accordingly....

For FRN 20.011 and v.20,01 and newer I sure stand corrected...:D...Thank you daba...👨🏻‍🏫
 
Last edited:

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