I came across the following error described below, how can I rectify this sort of error and why does this error is generated?
QIODEVICE::write:device not open
( the com port are also not visible in device manager)
Is this some sort of system error ?
If you have using just Qt then use QSerialPort otherwise you can use windows API createfile(), readfile() ,writefile() in Windows Platform.
You can take other information in:
http://support.microsoft.com/KB/115831
or this post in Stackoverflow:
Open a COM port in C++ with number higher that 9
Related
everyone. Recently, I was developing a method to access the camera extension unit through windows and send commands through the interface "ksproperty". There was a problem. Commands 0x01-0x19 can be sent normally, but commands 0x20 and above failed, and the error code 0x80070490 was returned. Is this a limitation of windows.
Yes, it is a limitation of usbvideo.sys. https://learn.microsoft.com/en-us/windows-hardware/drivers/stream/device-requirements-for-usb-video-class-extension-units
When I use QtMqttClient source code (download from officcal git repository) in my program On Windows PC, I got a error.
QMqttClient client;
client.setPort(1883);
client.setHostname("192.168.100.3");
client.connectToHost();
I received the following error message:
ClientState:Disconnected, ClientError:TransportInvalid
From the qt documentations, it said:
The underlying transport caused an error. For example, the connection might have been interrupted unexpectedly.
Then I copy the code to another pc with Windows, it worked fine. And worked fine on a Linux PC.
Is there somethings wrong on my computer or the Settings of Windows OS ?
After set breakpoint and add some debug code in my program , I found that the error was in QTcpSocket, the error was occured in the Qt network model lib.
As we know, Mqtt was baed Tcp,and in my program, the tcp can not establish connection,and err is QAbstractSocket::UnsupportedSocketOperationError, this confused me.
Then I search on google, I found a that someone encountered the same situation as me. And I found the solution here.
So, just add the code to the program before connect to server, the program worked well.
/* call before connecting to network. Easiest way is, just call somewhere at the beginning of the program */
QNetworkProxy::setApplicationProxy(QNetworkProxy::NoProxy);
Used JSSC to write/read data from a COM serial device. COM was detected but attempting to write or read gives this error: EXCEPTION_ACCESS_VIOLATION
This is a known bug in JSSC. Several other people noticed it too (e.g. https://github.com/arduino/Arduino/issues/6788). It seems to happen with Java SE 9 on Windows 10, x64.
Unfortunately, it appears that the JSSC project is no longer maintained/dead. However, as of this writing, there are over 150 forks, some of which appear to be active. For example, maybe the following fork might contain what you're looking for: https://github.com/aploese/spsw
In case you want to go with a different library altogether, this question provides a working example using jSerialComm: How to fix Java rxtxSerial.dll or jSSC-2.7_x86_64.dll Serial Port Error in Windows 10?
org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: An unknown server-side error occurred while processing the command. (Original error: unknown error: Device emulator-5554 is not online
This error can occur for serveral reasons as per given below-
Invalid app package name in testcase.
check usb debugging for device in enabled.
If you are using device then check connected as media/MTP/file transfer.
check you can see the device by suing adb devices command.
check the server is started with right port number.
if device is connected then set emulator false in code.
uninstall previous versions of app from the device.
if you share complete log we can diagnose the problem effectively.
Regards,
Anuja
Right Now I'm using Asterisk 11 on centos 6 operating system and using asterisk-java-1.0.0.m3.jar to establish communication between my java application and Asterisk 11.
I'm able to connect my java program with Asterisk
Issues I'm facing are
1.always at console message coming "Unsupported Version Asterisk Use at your own risk"
2.Unable to set property 'state interface' to 'SIP/0010' on org.asteriskjava.manager.event.QueueMemberStatusEvent:no setter found.Please report at http://jira.reucon.org/browse/AJ
My questions are:
1.Is there is asterisk-java-1.0.0.m3.jar source available anywhere so that i can edit source code and use it
2.I'm able to establish basic sip call,but getting issue as while making other type of calls which use other entities of same station like 0110 & 0210, which saved in extensions.conf & which work fine in Asterisk1.6 but not in Asterisk11.
As per my observation in Asterisk i added AppKonference module which is 3rd party module. & In java Program i write commands for that to establish channels using those entities.
But for communicate AppKonference in Asterisk API helps when Asterisk1.6 but not in 11.
Please suggest what I need to do is there is other asterisk and asterisk jar compatibility issue,if yes then what i need to do.
Please help
Sure, source can be found at
https://github.com/srt/asterisk-java
Also you can change agi compatability in /etc/asterisk/asterisk.conf