CmpApp library and the "AppStoreRetainsInFile" function

2023-04-17T06:53:12.729000Z

yes thanks this is help.

CmpApp library and the "AppStoreRetainsInFile" function

2023-04-16T06:17:02.031000Z

I think you need file placeholders ($$PlcLogic$$/Application/...) instead of direct filepath.

CmpApp library and the "AppStoreRetainsInFile" function

2023-04-15T09:06:42.535000Z

Have problem with AppStoreRetainsInFile, AppRestoreRetainsFromFile function. All time return
ERR_OPERATION_DENIED.
Maybe need add something in Codesys Config file (/etc/CODESYSControl_User.cfg) to make it accessible ? Using ARM SL 4.7.0.0 Runtime.

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-26T05:10:24.304000Z

Hi Patrik,

I have everything working well now using a different method posted in another forum.
https://forge.codesys.com/forge/talk/Engineering/thread/1f8eee253c/
This works perfect and is instant. I point the FB MemLocation to the ADR of a Struct. In the struct I have a bunch of different data types and variables, all of them work well. For the length I make sure it is more than all the data types and variables ( Real is 8 bytes and Int is 4 bytes etc ) Note: Under Application settings You have to enable "Use dynamic memory allocation" and set the maximum size of memory.
Hope this helps you out and a big thanks to arj3090.

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-25T08:48:27.945000Z

Hi Patrik,

I also get the 2 but only after "sudo service codesyscontrol restart" and when I use the save button via webvisu the execution is correct and returns 0.

From my testing I have to wait on average for 2 minutes for the .ret file to save ( may still be in ram during this time ) Sometimes it will be fine in 10 secs or 30 sec but will still fail at times even after waiting 90 sec so to be save if I wait 120+ sec it seems to work every time. I have tried the sudo sync commands etc but does not seem to help. The Log shows no faults. I don't know what format the .ret is or if there is a way to read the .ret to see if the file is being written to the SD card etc. I will post my code below.

PROGRAM AppRetain

VAR
    fbDelete            : FILE.Delete; (* Function block to delete the file *)
    (* The retain file <application-name>.ret is placed in the directory of the bootproject *)
    sFileName           : STRING := 'ApplicationTest.ret'; //  /var/opt/codesys/PlcLogic/Application
    pApp                : POINTER TO APPLICATION;
    Result              : RTS_IEC_RESULT; (* Result code *)
    xInit               : BOOL;
    SaveButton          : BOOL;
    ReadButton          : BOOL;
END_VAR

(* The retain variables are stores in a file and get retrieved afterwards. *)
IF NOT xInit AND SaveButton THEN
    (* First delete the retain file.
       This is necessary, because the function AppStoreRetainsInFile appends the data at the end of the file. *)
    fbDelete(xExecute:=TRUE, sFileName:=sFileName);
    IF fbDelete.xDone OR (fbDelete.xError AND fbDelete.eError = FILE.ERROR.NOT_EXIST) THEN
        (* Attention: It takes at least one cycle until xDone is TRUE *)
        fbDelete(xExecute:=FALSE);
        xInit := TRUE;
        (* Now, it's the time to save the retains. *)
        pApp := AppGetCurrent(pResult:=ADR(Result));
        IF pApp <> 0 THEN
            (* Store the variables in a file*)
            Result := AppStoreRetainsInFile(pApp,sFileName);
            xInit := FALSE;
        END_IF
    END_IF
END_IF 

IF ReadButton THEN
    (* Restore the Retain Variables from the file.
    For storing and restoring, the same pointer to application (pApp) must be used.*)
    Result := AppRestoreRetainsFromFile(pApp, sFileName); 
END_IF

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-25T08:28:16.600000Z

Hi!

Thanks for the response. My problem also originates from unreliable power with regular outages. The best solution would be a working UPS but we have tried to get the customer to use it but with no success. This is a work around more or less. If I can save the data in regular intervals then the problem would be solved. I will try to save it to a different file name.
but to my original question of the return value of the function. what does 2 mean? is it

ERR_PARAMETER   UDINT   16#2    Invalid parameter for this operation

from the CmpErrors2 interfaces lib?

Thanks in advance!

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-25T05:09:40.472000Z

Hi eschwellinger,

Thanks for the response. I have read through the other threads and understand the risks. I have used UPS Hats in the past for my other RPI projects with no issues. The problem with this project is it uses the RPI4 Compute module in a touch screen.

https://chipsee.com/product/industrial-pi-cm4-70-pa/

The screen does not use an SD but has EMMC memory ( my understanding a bit more robust memory ) There is no UPS available nor built into the screen. I do have a shutdown button for the system to be shutdown correctly. The issue is the supply of electricity is unreliable with regular outages. So I need to make sure any changes to the setpoints etc are saved.

I have the AppRetain working but not reliable, maybe works every 1 in 5 times. I have also been using Sudo Sync and sudo sync -f /var/opt/codesys/PlcLogic/Application this seems to help a bit but not every time. I will try your recommendations of using a different file name and see how I get on. Note: I only plan to save to the disk if the value of the setpoint changes. I have also tried the Persistence Manager without success ( would only work the odd time )

Thanks,
Matthew

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-25T04:43:08.594000Z

Hi,
I try to explain, the persistence/retain feature:
Usually if you do nothing in your application and you shutdown your plc graceful( not just poweroff), this means Linux shutdown or - you have for example a UPS connected, Application.ret will be written by tthe runtime, no need to call anything.
on next restart the Application.ret will be loaded with the bootproject on startup.
This is how retains in generell work.

Now if you trigger this 'save retains' from the application to application.ret it might that these interact with the in background working feature.
Try to save the retains with another name.ret, and recover them on startup of your application.

Altough the proper solution is to have a UPS and a graceful shutdown. Then no need to do anything with this function and additional you protect your OS against damage on the SD card/flash, makes it more robust against the ' I could not start my OS because filesystem is corrupt' problem.

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-24T20:20:29.590000Z

Can you post your code and I can see if I can help.
I think my problem is related to the functions having issues with child applications.

CmpApp library and the "AppStoreRetainsInFile" function

2022-01-24T20:00:20.381000Z

Hi Patrik,

I did try with my own save button as a test. I think my issue could be reading the file back. Or it's just not writing to the file correctly. If I restart the CodeSys service after saving it should read that .ret file, but it's just reading the old original file. Maybe if I back up the file and remove it and see if it will create a new file or create a blank file and see if any data is being stored.

My Plan was the store all my retain variables for the parameters/setpoints etc in a struct and monitor the struct for any changes in values and then trigger the save automatically using the AppRetain. But I can't even get a simple test to work correctly. So hopefully someone who has been down this track can shed some light on this issue.

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