Delay with POST over Talk2M

Ewon Support Basic and Java
#1

I’ve been seeing some issues with ajax POSTs when connected over Talk2M. I have a PLC that has a webserver built in (WAGO 750-881) that I have custom webpages on. Those pages have some Javascript managing data to and from the PLC using the jQuery GET and ajax POST, which work fine when directly connected to the PLC (more or less instantaneous). When connected thru Talk2M they are extremely delayed (2-15 seconds) or ignored. The internet connection is fine (hardwire WAN) and the GET functions as if it were directly connected.

Is there a known issue with using a POST over Talk2M? Any other thoughts of what might be causing this delay? Need any more information?

#2

Hello sbrc!
Are you executing this post client side and posting to a device behind the eWON?

Are you connected to eCatcher when doing so?

#3

Yep. The POST is initiated by the client browser which goes thru the tunnel created by eCatcher to the server (PLC) on the other side of the eWON LAN.

#4

Could you possibly add to your ajax call to determine the average time it takes for completion?

Add the following to your ajax and provide the results after a few runs.

//important line added
var startTime = new Date().getTime();
$.ajax({
     type: "...",
    etc etc,
    success: function(){
         //Start line added
         var total = newDate().getTime() - startTime;
         console.log("Total Time: " + total);
        //End line added
    }
})

This should give us some idea of how long the query is taking to complete.

Do you know if you have plug n’ route enabled on your eWON? The additional overhead of plug n’ route may be attributing here as well.

#5

@sbrc

I wanted to reach out as it has been some time since I have seen an update on this this thread. If you could advise if you are still facing an issue here.

#6

As I have not heard back on this thread I just wanted to provide info on a similar issue.

Another customer had a similar issue, it ended up being a delay caused by the overhead of the reverse proxy with M2Web and the eWON device.

Development was reviewing this issue, there is nothing on this end that can be done.