VNC and remote control and monitoring
Added by Anonymous over 18 years ago
The Leginon manual and course notes suggest installing VNC to allow the microscope PC (and possibly the Leginon computer) to be remotely monitored or controlled. Are many people at Scripps doing this? We're interested in continuing to monitor or control the microscope PC and Leginon (running on another computer) after Leginon has been set up and I have gone home for the evening. An extra complication in Leeds is this has to work through a firewall in the case of the Leginon computer and two firewalls in the case of the microscope PC. However, I have tried it and it does appear to work. I'm not sure what the best setup is in terms of running things via X windows or VNC and which systems they run on? I would tend to avoid having too much stuff running on the Leginon laptop if possible. However, it is the Leginon laptop which allows us to get through the second firewall and the simplest solution involves running a VNC client to the microscope PC and a VNC client to the Leginon laptop, both running on the Leginon laptop (with the VNC clients displaying on an X terminal at home). I've been trying to avoid this by use of ssh port forwarding but having some difficulties. Also, I found that in the case of the Leginon laptop it is necessary to either start Leginon from within a VNC virtual screen X server right at the beginning or use a special VNC server that can allow connections to an already running X server (and this is only available in some of the releases and flavors of VNC),
William
Replies (3)
- Added by Jim Pulokas over 18 years ago
We use VNC all the time because it saves us from having to go into the microscope room for certain tasks. We have been using TightVNC for a few years with no problems. We have a VNC server running on our Tecnai computer and then we run a client in the control room where we are monitoring Leginon. When we have to restart the Leginon client on the Tecnai, we almost always do it through VNC rather than walking into the microscope room to do it. The is our most common use of VNC, but we also use it to check on the status of things, such as the vacuum system and also to verify that Leginon is doing what it is supposed to do.
Hopefully someone else can give their experience, but I think it is less common for us to use VNC from home. I think most people will monitor the progress of Leginon through the various web tools. We have a system wide firewall that blocks almost everything except ssh. I have tried to monitor the Tecnai from home by first doing ssh to one of our linux machines (with X forwarding: ssh -X) and then open a VNC client to the Tecnai. I think it worked, but it was very slow. It is a good way to close the column valves if you are running over night and your want to quit. Scripps also has a Virtual Private Netowrking (VPN) system that allows people to connect to the Scripps network from home over a secure connection. I have never tried this, but that would allow us to run VNC client on a home computer and connect directly to the VNC server on the Tecnai.
Jim
VNC from home - Added by Anchi Cheng over 18 years ago
I have used VNC to close column valves from home through TSRI VPN. If I don't have VPN connected, the access is denied.
Anchi
- Added by Anonymous over 18 years ago
Hi, we use vnc to connect to the TEM Server through our firewall. In our case, we have first to connect to a Main server using ssh protocol, then ssh to a linux computer, which is connected to both, the institute network and our local subnet with the TEM server and the computer running leginon. From there, I start the vncviewer using "vncviewer -geometry 1600x1200 -compresslevel 1" e.g. to connect to the TEM server. From home, I use putty as ssh client and Exceed as X-server for windows. This works fine to control the TEM state, however, the transfer rate is to slow to moinitor the camera output.
Thorsten