Rosstalk and SendMessage with callback issue

Automation & Control
1

Hi,

I’m trying to put in place a tcp communication using rosstalk and my device.

I’m using the sendmessage method with callback. The callback function is the one supposed to give me the response of my device a a tcp message.

The problem is that the response is always a null string.

I was wondering if there is a bug in Dashboard or if i’m doing something wrong.

The code looks like this:

function callback(success, sentData, resultString, exception)

{

ogscript.debug("TCP result: " + resultString);

}

var ip = params.getValue(0xC,0);

var port = params.getValue(0xD,0);

rosstalk.sendMessage(ip, port, message, callback);//Send message to external device
I would appreciate if somebody could shed some light on this issue.

Thanks

Bruno

2

Hi Bruno.

Unfortunately, the rosstalk.sendMessage will typically terminate the message after it has been sent without waiting for a response. The only exception to this is if the message sent ends with a “?” character. This is because rosstalk.sendMessage was designed for “fire and forget” messaging.

If you need to engage in a multi-message conversation over TCP/IP, one option you have is to use a tag (which can act as a server or connect as a client).

Hope this helps.

James

#DashBoard

3

Thanks James for the quick answer.

Bruno

#DashBoard

4

You’re welcome - please note that the post should have said " tag" (the forum originally hid the tag because I hadn’t escaped the brackets).

If you have any issues using the listener, please post back and we’ll do what we can to get you sorted.

James

#DashBoard