trouble with Wago 750-841 HTTP system

Hi all,

I am experiencing a very weird trouble with Wago 841.
System works fine, and is connected to two 750-342 couplers
(the 841 reads and writes them using Modbus UDP), and
to an HMI device (still Modbus, but TCP) protcol.
Everything looks allright, untill I try to use HTTP.
The 841, for those not knowing it, can hold inside of
its flash memory a set of HTML pages and you can upload them
using FTP protocol. I did quite a big work to design all
the pages, using pure HTML, Javascript, some small images (all
stored inside the 841) and the SSI system (server side includes).
The SSI is the only way to dialog with PLC memory (All %M locations
for me). The pages just get data (words, double words, bytes)
and, with some forms, do post some other data modifying
settings. Basically I do a supervision just browing the PLC.
Everything looks ok, untill something bad happens and the PLC
just CRASHES. Most of the led lights on the coupler start to
flash (between red and green) and there's no way to gain
control: I need to shut down the coupler and power up it again.

It seems to me that the more complex a page is (hence more
data, hence more SSI calls), the easier it crashes.

Anybody experienced this ??? I am in trouble since I've already
TWO system installed, and I cannot gain time anymore delaying
the end of works document delivery.
WAGO claims nothing happens, even if they're providing a new
kernel. New kernel should contain upgrades for threads programming
(that I don't use), and there should be nothing about HTTP.
I tried messing with the Watchdog timers and setting, but w/o
success. First I don't know how all the setting (mostly the
flags) work (manual ain't clear), and second wago claims those
settings are all modbus related.

Any help MUCH apreciated.

Thanx
Luca

Have you tried to email your entire project to WAGO for them to reproduce the problem ?

nope, I didn't... and I wouldn't really like to do that.
My software isn't a pure application, it's rather a stand alone
system, configurable with a Pc program (still by me). Basically
it's a kernel, and with configuration program you can make
it doing tons of things.
I am even about to patent some stuff about this thing, and I really
FEAR that. BTW wago tech support here didn't ask me to do that.

Thanx
Luca

Can you make a version of the project that doesnt contain the sensitive stuff, but so the abnormal behaviour still appears ?

I am stripping it down indeed but takes time

Where is a bug in the flash in the 750-841, call wago to replace it.


Regards Lars Hjorth

Lars Hjorth said:

Where is a bug in the flash in the 750-841, call wago to replace it.
Regards Lars Hjorth

Click to expand...

Hi Lars.
Yes, indeed that's what it seems.
I sent my stripped project to 'em, and they said that with
their new HW and SW (Both inside plc and codesys) there's no
troubles.
Yesterday I received a new 841 set (there's written something
different like 2B instead of 1B on the serial port / runswitch
little door). I installed the new codesys (ver 2.3.2.7, build
feb 2 2004) and give it a try.
Test ended in a smoke cloud, because the new codesys does
see the 841 as target, but doesn't let me declare anything
over %MW4095. I mean, if I declare %MW5000, just to make
and example, I get an INVALID ADDRESS compiler error.
I went on the directory ...1CoDeSys V2.3\Targets\WAGO\
and replaced the file "0750-0841.trg" (size 4013bytes)
with the one from former CodeSys version I had (3335bytes).
TADA! It does compile 100%.
I can do everything, but the trouble with html pages I described
is still there (but this time I didn't even touch the watchdog
settings, I left 'em STOCK).

When I use the NEW .TRG file I get a different TARGET SETTING
windows, on the MEMORY LAYOUT tab:
See the data that aren't the same anymore:
BASE / RETAIN 16#30002000 (was 16#30000000)
SIZE / CODE 16#80000 (was 16#100000)
SIZE / MEOMRY 16#2000 (was 16#6000)
SIZE / RETAIN 16#4000 (was 16#6000)

...and ofcourse all the field are disabled so I cannot
modify!!!

Now I am trying to contact wago again.....
I _HOPE_ that using the old .TRG file is critical for the functioning.

Any idea?

Ciao
Luca

contact beckhoff as they are making all electronics and wago only sells it.
and produces the stuff
wago is original a plastic company making electric connectors

I have my own issues with Wago. My original program was running in the 842 and I always wanted to upgrade to the 841. The script in the 842 would not convert to the 841, the web stuff was completely different. Wago recently changed the firmware in the 842 and my stuff won't work from the web page. Everytime you try to access port 8080, it locks up the 842. I sent my program to Wago to get them to convert it, since I couldn't get it to work. The program works fine in the 841, now. I had to re-make the web pages and am having problems with the SSI WRITEPI command. They sent me the following. I haven't tryed it yet.

The XMLHTTP object is complicated to handle,
please check if the MSXML Version 3 ist installed on your PC.
Also the "try-catch" block is needed under XP.

function PostProcessData()
{
var rpc = "http://" + document.frmParam.edtHOST.value + " /WRITEPI";
var params = PrepareWriteParams();
var objXMLHTTP = new ActiveXObject('MSXML2.XMLHTTP.3.0');
objXMLHTTP.open("POST", rpc, false, "admin", "wago");
objXMLHTTP.setRequestHeader("Authorization", "Basic dXNlcjp1c2Vy" );
try{
objXMLHTTP.send(params);
}catch (e){}
GetProcessData();
}



The following code only work if the page stored on the 750-841.
It is an alternative to example 7 and 8

function PostProcessData2()
{

var adr1 = "MW100";
var value1 = 2; //RequestData
var format1 = "%d";
var adr2 = "MW101";
var value2 = 4711; //Request_ID
var format2 = "%d";

window.focus(); //GET THE FOCUS!!!

document.write("send request...");

document.write("<form action=\"/WRITEPI\" method=\"POST\" name=\"rq_form\">");
document.write("<input type=\"hidden\" name=\"ADR1\" value=\"" + adr1 + "\"></input>");
document.write("<input type=\"hidden\" name=\"VALUE1\" value=\"" + value1 + "\"></input>");
document.write("<input type=\"hidden\" name=\"FORMAT1\" value=\"" + format1 + "\"></input>");
document.write("<input type=\"hidden\" name=\"ADR2\" value=\"" + adr2 + "\"></input>");
document.write("<input type=\"hidden\" name=\"VALUE2\" value=\"" + value2 + "\"></input>");
document.write("<input type=\"hidden\" name=\"FORMAT2\" value=\"" + format2 + "\"></input>");
document.write("</form>");

window.setTimeout("document.rq_form.submit()", 1);
}

Could anybody help with a manual about the SSI commands? I don't find anything on Wago's webpage. I'm using the 750-841 and I'm playing with the html functionality. It should also run on a PDA.

I had this experience. I solved this problem by power recycle the module. Can see the picture, hopefully same.