Hi,

I wonder if anyone can help. I am writing an application to a Linn Kivor, and I want to download all of the album and track information to the Pronto to allow me to scroll through all of my albums.

At the moment, the only way that I can talk to the server is using a Sync socket on the Pronto but this obviously locks the device while this is operation. When I use a for next loop to run through approx 700 albums, the most that I can download is about 500 before the for-next loop times out.

What I would really like to do is to use an Async socket to talk to the Kivor, but I cannot seem to get any response when I try Async. I suspect that the Kivor is not closing the socket after responding, but even trying to force the socket closed does not have the desired effect.

The code I am using for Sync socket is shown below. The Kivor will always send a '~' at the end of a message so I have tried looking for this on the incoming string and then closing the socket based on this, but this does not seem to work.

I am new to Javascript, so any advice would be gratefully received.

Many thanks.

------------------------

......
if (message_counter==62)
message_counter=0;
else;
message_counter++;
var socket = new TCPSocket(true);
socket.connect('192.168.1.100', 6789, 3000);
var message_out = "#pronto#@"+zone+"@"+message_number[message_counter]+msg+"~";
get_checksum(message_out);
socket.write(message_out+checksum+"\r\n");
var output = socket.read(500,200);
socket.close();
full_output[0]=output;
System.delay(150);
......
------------------------

Perhaps paste in the code you try to use for the async Socket?

FWIW, you don't *have* to do everything once the connection closes. This is merely a useful convention for the likes of HTTP which is (most often) a one-transaction-per-connection protocol.

You can (and sometimes have to) do your processing in the data-arrived callback - though you cannot guarantee that all the data you need to work on will arrive in a single invocation of the callback, of course.

Chris.

There are some examples of working with async tcpip sockets posted on my web site www.the-gordons.net. You should be able to find them. If you can't well TCPIP sockets is much harder than browsing around a web site

Hi all,

Thanks for the replys. Barry I will have a look at your website.

Meantime here is the Async code that I am using which returns 'empty socket' telling me that the Ondata subroutine is not being called.

Thanks again for all the help.

var socket = new TCPSocket();
var result = "empty";
socket.onConnect = function()
{
write("#pronto#@Z01@1$PLAY$~\r\n");
}

socket.onData = function()
{
//var data = read()
result += read();
if (result.indexOf("~") != -1) this.close();
};

socket.onIOError = function(e)
{
CF.widget("LINE1")= ( "Socket error: " + e);
};

socket.connect('192.168.1.100', 6789, 3000);
CF.widget("LINE1").label = "finished"+ result;

Is it your thought that the unqualified read in the onData function, or the unqualified write in the onConnect function will address the socket? It might, as some languages support an implied qualifier and some don't. After all, read could be another fiunction having nothing to do with sockets, or you may have multiple sockets active that need to be read. I always use explicit qualification as a matter of practice


I do know for sure that socket.write will work as will socket.read.
Hope that helps

Hello Barry,

Looks like your suggestion was a good one despite the Pronto manual saying that 'read' would work as it was in scope. I can now send commands to the Kivor server which are acted upon but I cannot read the response. The code I am using is as below - I don't get any errors but when I run the script 'LINE1' is showing

receiving + functionread(){
[native code]
}

Any ideas

var socket = new TCPSocket(false);
var result = "";
socket.onConnect = function()
{
socket.write("#pronto#@Z01@1$PLAY$~\r\n");
};

socket.onData = function()
{
var received=socket.read;
result += received;
CF.widget("LINE1").label="receiving"+ received;
};

socket.connect('192.168.1.100', 6789, 3000);

OK so I figured it out - missing ()

Here is the working code for anyone else who wishes to use it.

Many thanks to all.

---------------------------------

var socket = new TCPSocket(false);
var result = "";
socket.onConnect = function()
{
socket.write("#pronto#@Z01@1$PLAY$~\r\n");
};

socket.onData = function()
{
var received=socket.read();
result += received;
CF.widget("LINE1").label="receiving"+ received;
};

socket.connect('192.168.1.100', 6789, 3000);

FYI, while inside any of the TCPSocket onXXXX functions, the keword 'this' is set to the current socket or callback object. The same applies for RS232 Serial onXXXX functions as well.

As a result, your code socket.read() is functionally equivalent to this.read().

I provided a post discussing such concepts quite a while back. If you want to read more, do a search for +serial +this +keyword and see the posts that come up (first one contains original discussion).

.

Macdomm2, Pronto manual is correct. The unqualified read or write is NOT in scope.

Lyndel, but without the "this." qualifier the partial reference to read or write is meaningless; correct?

I believe read() or write() has ALWAYS worked when in the immediate callback function. When the remote invokes a callback, it sets the scope to be that of the javascript object to which the callback is attached.

Could be, as I said I always qualify a reference so I would never know

Me too. But it makes it nice to know because a socket is nothing more than a javascript object so you can attach the partial response string to a member field of the socket such that you don't need extra variable.

socket.onData = function()
{
this.partialData += this.read();
// check partial data and if end of message is complete extract your part,
// process and clear partial data.
var toRemove = processMessage(this.partialData);
this.partialData = this.partialData.substring(toRemove);
}