Codesys :Retain Persistent variable in PRG - Device Undiscoverable

Manikandan_pilz · Post by **Manikandan_pilz** » 22 Nov 2022, 12:09

Hi,
In my project I am using Revolution PI Connect + along with the REvPI DIO Module. And I have Codesys and Nodered running on it.
I was trying to use the Retain Persistent variable in my Project.
I have declared the variable in my PRG. [I missed to read this post from Codesys 'https://forge.codesys.com/forge/talk/En ... 6615/#aa4c']

After download and restart my hardware, now I am unable to discover the h/w both in codesys and through Putty, But I can ping the IP address.

Any inputs on making this device connecting to the development tools like Putty or Codesys is highly appreciable?

Your inputs highly appreciable.
Best Regards,
Mani

Post by **u.biakoup** » 23 Nov 2022, 15:23

Hi Manikandan_pilz,

Please follow the instructions of Revolution checklist and Codesys Checklist. I think, it's a network issue.

Best Regards

Ulrich Kouatang Biakoup | Technical Support

Manikandan_pilz · Post by **Manikandan_pilz** » 28 Nov 2022, 13:31

hi ,
Thanks for your response. It's not related to Network issue, because i can reach the h/w using ping command and not through Putty, Codesys as well as from the web browser.

Given this condition, can you suggest me in the method I can connect to this device for the Fresh Logic download apart from the Ethernet port ?

Best Regards,
Mani

Manikandan_pilz · Post by **Manikandan_pilz** » 30 Nov 2022, 01:22

Hi,

In my Project, I am using RevPI Connect + [16 GB].
I have CodeSys Runtime in my project [Runtime Licensed]
I tried to configure the Retain and Persistence Variables in my Project, After Power-off and Power-On the Variables are not holding the previous Values.
Does Revolution PI hardware's Support Retain and Persistence Variables in Codesys? If so, can you, please advice me on creating the Retain and Persistence variables
Your valuable input highly appreciated.

Best Regards,
Mani

Post by **u.biakoup** » 13 Dec 2022, 09:07

Hi manikandan_Pils,
Retain Persistent variable is not supported with RevPi since it requires separate EEPROM interface to store the variables.
As workaround the variable status could be saved to file and read again on statup.
Write and Read File using Codesys.
https://forge.codesys.com/forge/talk/En ... 5550f2e37/

Best Regards

Ulrich Kouatang Biakoup | Technical Support

Manikandan_pilz · Post by **Manikandan_pilz** » 14 Dec 2022, 11:00

Hello Ulrich Kouatang Biakoup,

Thanks you very much for providing the detail and the link. I will implement these and get back to you if any further support required.
Few more info on this persistence variable, I have configured the Persistence Variable.

: Configuration; Codesys_Persistence.png (38.06 KiB) Viewed 16806 times

1. the values are retained, if execute 'reboot' command form codesys or node-red, but the values are getting erased if I remove the power and reconnect the Power , Is it a right behavior ?
2. Is there any chance of having h/w with EEPROM form revolutionpi in the future to tackle these kind of requirement ?

Bet Regards,
Mani

Post by **u.biakoup** » 16 Dec 2022, 12:41

Hello Manikan_pilz,
The behaviour is right. The Revpi's isn't yet able to perform that kind of features.
Thank you very much for the suggestion. We will think about that in the future.

Best Regards

Ulrich Kouatang Biakoup | Technical Support

ienecode · Post by **ienecode** » 29 Apr 2024, 09:25

To do persistent variable in devices based on RPi I use this way:

https://help.codesys.com/webapp/f_appli ... n=3.5.17.0

Regards