EthernetKRL connection does not close when submit is deselected

I have EKI running in a user defined submit (multi-submit package installed) on a KRC4. I am not sure how to close the connection when deselecting the submit.

This sometimes causes an error when the submit is selected. Error - Connection is already initialized. I am trying to find a way to check if the connection is initialized before calling EKI_Init(), but I have not found a valid way to check this. IF NOT RET_Init.Connected THEN EKI_Init() also causes an error.

I will continue looking for a way to check if there is a connection before initializing (maybe with $FLAG[x]...?), but I also want to know how to close the connection when the submit is deselected. It doesn't make sense to leave it open when it is not in use.

I found some useful information in this thread How to tell if a connection has already been opened in KUKA.EthernetKRL, but I haven't figured out how to implement the suggestions without getting more erros:

IF RET.Msg_NO==0 THEN...

IF NOT RET.Connected THEN...

I checked the EthernetKRL30 documentation as recommended as well, but it only says to "Delete overprogrammed function" to solve the already initialized error. I only have EKI_Init in the program one time. The issue is that it is called more than once when the program is run again. Actually, the issue is that the program does not close when deselected. I would like to handle both issues, but I am a bit stuck.

Configuration:

<ETHERNETKRL>
    <CONFIGURATION>
        <EXTERNAL>
            <IP>172.31.1.44</IP>
            <PORT>59152</PORT>
            <TYPE>Server</TYPE>
        </EXTERNAL>
        <INTERNAL>
        <ENVIRONMENT>Submit</ENVIRONMENT>
            <ALIVE Set_Flag="1" Ping="200" />
            <TIMEOUT Connect="666" />
            <IP>172.31.1.4</IP>
            <PORT>59152</PORT>
            <PROTOCOL>TCP</PROTOCOL>
            <MESSAGES Display="error" Logging="warning" />
        </INTERNAL>
    </CONFIGURATION>
    <RECEIVE>
    </RECEIVE>
        <SEND>
        <XML>
            <ELEMENT Tag="ThingToSend" Type="STRING" />
        </XML> 
    </SEND>
</ETHERNETKRL>

Code:

&ACCESS RVO
&REL 23
&PARAM EDITMASK = *
&PARAM TEMPLATE = C:\KRC\Roboter\Template\submit
DEF TCP_Streaming( )
;FOLD DECLARATIONS
  ;FOLD USER DECL
  ;ENDFOLD (USER DECL)
;ENDFOLD (DECLARATIONS)
;FOLD INI
  ;FOLD USER INIT
; I have tried the block commented out below, but 
; it had the error {%variable} value invalid
; I am not sure how to initialize RET_Init in the .DAT
; IF NOT EKI_Init.Connected THEN
;     RET_Init=EKI_Init("ThingSender")
; ENDIF

    RET_Init=EKI_Init("ThingSender") 
; this causes the already initialized,
; if the submit stopped while the connection was open 

LOOP
;FOLD USER PLC
  IF _stopSubmit THEN
    ; break out of the loop
    _stopSubmit = FALSE
    EXIT
  ENDIF
  IF sendAThing THEN
    RET_Open_Event = EKI_Open("ThingSender")
    RET = EKI_SetString("ThingSender", "ThingToSend", "Thing")
    RET_Send_Event = EKI_Send("ThingSender", "ThingToSend")
    RET_Close_Event = EKI_Close("ThingSender")
  ENDIF
ENDLOOP
RET_Clear = EKI_Clear("ThingSender")
END

I had to dumb down the code, but this is the basic skeleton of what is happening.

This service is working. I receive data every time I sendAThing. My main issue seems to be stopping and starting the submit. I want to add error handling, but I am not sure how to achieve this.

SkyFire and Panic Mode, sorry for the typo in the dummy code, I was adding back in the block of code that caused the error and mistyped in the posted code. It was correct in my original post about the error. The original code did use IF NOT RET_Init.Connected THEN.

I found a solution to the first error.

The error was: {%variable} value invalid. Cause: Calling RET_Init.Connected.

To get rid of this error, I had to Declare and Initialize RET_Init in a .DAT file. I couldn't figure out how to do this before, but here is how I got it working, in case anyone else runs into this issue.

DEFDAT TCP_Streaming PUBLIC

DECL GLOBAL EKI_STATUS RET_Init = {Buff 0, Read 0, Msg_No 0, Connected FALSE, Counter 0}

ENDDAT

I still would like to know how to tell the EKI connection to close when this submit program is deselected. It seems problematic to leave the connection open while it is not in use. Can this be done with something like an interrupt, or would I have to use another submit to check if this submit is still running and close it from there? That doesn't seem like a real solution.

I receive the data in my external program. I am only sending from EKI.

After testing my application some more, I am still getting the connection already initialized when calling EKI_Init().

My application Initializes the connection only once at the top of the program. I then open, write, send and close the connection on each loop when there is something to send. When the program is reset, my RET_Init.Connected is FALSE, but the connection is still initialized. This doesn't seem possible. If it is possible, I don't see how I can check if the connection is initialized. I tried IF NOT $FLAG[1] THEN, but $FLAG[1] is only TRUE for a brief second when the program is running, so this still lets me initialize an already initialized connection. I am about to just put ON_ERROR_PROCEED on the EKI_Init() call, but I don't like this as a solution.

  IF NOT $FLAG[1] THEN ;Flat[1] is set ALIVE by Config
    IF NOT RET_Init.Connected THEN
      RET_Init=EKI_Init("ThingSender")
    ENDIF
  ENDIF

Here are the If statements I am using. I am not sure what else I can check before trying to initialize the connection.