I'm trying to connect to an OPC Server using the python Open OPC library, it is working fine with a Matrikon OPC Simulator, however when I try to connect it to the actual server the client seems to be hanging on the OpenOPC.open_client method, I added some debug messages in this API and found that the following API in OpenOPC.py is hanging:
import Pyro.core
Pyro.core.initClient(banner=0)
server_obj = Pyro.core.getProxyForURI("PYROLOC://%s:%s/opc" % (host, port))
return server_obj.create_client() #this API is hanging
So if anyone has used OpenOPC to interface with OPC Servers, and has run into similar problem, please let me know. cheers!
When using OpenOPC in Linux, you can't use DCOM.
So you need to use OpenOPC Gateway Service and the "open_client" method.
This service must be installed and running in the actual OPC server for your client to access it.
Related
I'm building a home automation project, I have a websocket server I've built with pythons websocket and asyncio libraries. When I use a python client testing script and use local host to connect, it works perfectly. However, when I use my computers IPv4 address it doesn't. I've tried connecting using esp's, raspberry pi's and the same testing script on the same computer. Any idea's?
I'm creating a python flask api on remote desktop and running it on localhost of remote desktop.
Is there anyway I can access this api from my local machine?
We are working in a team and I want to share this with my team members, but this is confidential and not to be deployed on open server.
We want to post and get the result with every member's local machine from api runnnig on remote desktop.
Both of our local machines and remote desktop are windows10.
Sorry for being abstract but I'm searching for any way out. Thanks.
Well, you should open your way to this API. You'll have to set up a VPN or IP address filter in the server so you can access the server from your network while still have it secured on the Internet. You can also setup a simpler proxy if you prefer it. I'll not cover the details on how to setup a VPN or proxy since it can get pretty extensive, but a Google search will help you out find the best alternative for you.
AFAIK, the Remote Desktop Protocol does not allow for any kind of VPN. However, if you can switch to TeamViewer, it does have an easy to setup VPN system that will allow you to get into the network with few configuration. Once a VPN is configured, it will work like if you were in the same network as the server, so from there you can access your API from your host machine by just going to the IP address of the server.
Do notice the security policies of whoever owns the server, since you can get into trouble if you don't have permission to enable some access from the outside. Security goes always in front of comfort.
Short term solution:
Firstly download ngrok for your operating system.
For debugging and testing purposes you can expose a secure tunnel connection to your API by running this command in your command prompt / terminal.
ngrok http <PORT_NUMBER>-host-header="localhost:<PORT_NUMBER>"
Where PORT_NUMBER is the port number in which your flask application is running.
Example if your flask application is running at port 5000 then simply execute this command:
ngrok http 5000 -host-header="localhost:5000"
Running this will give you two hostnames one with HTTP and other a secure HTTPS connected by a tunnel like this for a duration of 8 hours after which the command needs to again re-run.
Which you can call remotely
Long term solution:
Deploy flask application using FastCGI
or
To a cloud infrastructure provider like Microsoft Azure which gives readymade templates for flask applications.
My requirement is to communicate socketio with nodejs server to Raspberry Pi running a local Python app. Please help me. I can find ways of communication with web app on google but is there any way to communicate with Python local app with above mentioned requirements.
It's unclear exactly which part you need help with. To make a socket.io connection work, you do the following:
Run a socket.io server on one of your two computers. Make sure it is listening on a known port (it can share a port with a web server if desired).
On the other computer, get a socket.io client library and use that to make a socket.io connection to the other computer.
Register message handlers on both computers for whatever custom messages you intend to send each way and write the code to process those incoming messages.
Write the code to send messages to the other computer at the appropriate time.
Socket.io client and server libraries exist for both node.js and python so you can either type of library for either type of system.
The important things to understand are that you must have a socket.io server up and running. The other endpoint then must connect to that server. Once the connection is up and running, you can then send message from either end to the other end.
For example, you could set up a socket.io server on node.js. Then, use a socket.io client library for python to make a socket.io connection to the node.js server. Then, once the connection is up and running, you are free to send messages from either end to the other and, if you have, message handlers listening for those specific messages, they will be received by the other end.
I am trying to setup Pusher to send messages from server to server. I do not need a client setup. I am trying to make the one server aware the other server is finished doing a particular task. Can anyone help with this?
Thanks
I work for Pusher. Have you tried using our server libraries? Some platforms have both a client (subscription) and server (publishing) library so you should be able to do what you want.
I'm have an issue with running the built in Python server that comes with 3.1, this may or may not be an issue with Python, in fact it probably isn't.
I start my server in the correct directory with "python -m http.server 8000" as the documentation suggests (http://docs.python.org/release/3.1.3/library/http.server.html).
When I navigate to that port on my local network with another computer using the url 192.168.2.104:8000 (my local ip and the port) my page loads. When I use my global IP, however, it stops working. Port 8000 is forwarded correctly. I used www.yougetsignal.com to verify that port 8000 was open using my global IP. Why in the world would Chrome be saying "Oops! Google Chrome could not connect to [REDACTED]:8000" then? Other server applications (such as my Minecraft server) work just fine. Is there something I'm missing? Furthermore, why would yougetsignal connect to my port but not Chrome?
With most routers ports are only mapped when someone connects from the outside (internet/WAN). You're testing it from your LAN so basically you're connecting to your router when you use your public IP. Ask a friend to test, i.e. from an outside connection.