Conventions and Tools¶

Overview¶

The user interface environment to the DAQ system is hosted in VNC servers running on DAQ cluster computers at various sites. Users interact with these via VNC viewers hosted on control room desktops, and for experts, on their own desktop or laptop.

The NovaControlRoom package contains icons and scripts to automatically set up the needed ssh tunnels, and launch the VNC viewers. See docdb-8406 for a User's Guide.

VNC Servers¶

To set up VNC servers for the control room, see the VNC Setup How-To.

VNC Viewers¶

The command to start a viewer is including in the script launched by the desktop icons described in the User's Manual mentioned above, but the underlying command is of the form

 vncviewer -Fullscreen -Shared -passwd ~/.vnc/passwd :<NN> 

where

 -Fullscreen # starts in full screen mode
 -Shared # keeps other users from getting disconnected from the server when you connet
 NN # two-digit port number (relative to 5900) 

Conventions¶

VNC Servers¶

In the current model (as of 2013-04-09), we run up to 4 VNC servers for each detector. In order to allow for different desktop environments on a single host machine, each VNC server on is run under a different account, using a dedicated port. We tend to use certain servers for particular functions, but this is subject to change.

Station	Functions	Account	Port
1	FD Run Control Message Logger	novacr01	5951
2	FD Event Display Online Monitoring APD Cooling GUI	novacr02	5952
3	Synoptics	novacr03	5953
4	Camera pages beam pages	N/A	N/A
5	ND Run Control Message Logger	novacr01	5951
6	ND Event Display Online Monitoring APD Cooling GUI	novacr02	5952

The servers for each of these is set up to occupy a 2x2 monitor grid, with total pixel count 3840x2160.

Two VNC servers run on the nova-daq-04 Control Room desktop in the Fermilab 1st floor control room, hosting webcam displays.

From off-site, webcam and beam pages can be found on the What to do on Shift links site.

Note that VNC has a port base of 5900. However, in addition to the VNC connection itself, it also uses a port for the X11 connection 100 higher than the VNC port. Since general X11 connections use ports starting at 6010, and assuming less than 40 open connections is a safe bet, a good assumption for VNC port ranges that avoid conflicts with X11 would be 5900-5909 and 5950-5999.

The table below gives the VNC server host name used for each system:

Detector	Host	Status
NDOS	novadaq-ctrl-master	Defunct
NDSBTest	novadaq-ctrl-master	Defunct
FarDet	novadaq-far-master-02	Operational
NearDet	novadaq-near-master	Operational
NearGateway	novadaq-near-gateway-01	Operational

(See novadaq_apdtest for more information on NDSBTest)

ssh Tunnels¶

ssh tunnels are required to access the port for a VNC server on a remote host (e.g., novacr01@novadaq-ctrl-master.fnal.gov for station 1 on NDOS) from a localhost (e.g., your laptop, or a control room desktop). Once launched, the tunnel can remain active indefinitely. The ssh command has the form

ssh -L <local_port>:localhost:<remote_port> -N -f -l <remote account> <remote host> 

The ssh tunnel is authenticated using a kerberos ticket on the localhost, usually for a special use (i.e., non-personal) principle. That principle must be in the k5login file for the remote account, and the remote host must be directly reachable from the localhost (i.e., the localhost must be in the fnal.gov domain.)

Since a single desktop will often have connections to the "same" display on multiple detectors, we need to have localhost port assignments vary by detector. The scheme in use by the NovaControlRoom package is

Station	Detector	Remote Port	Local Port	Status
1	NDOS	5951	5961	Defunct
2	NDOS	5952	5962	Defunct
3	NDOS	5953	5963	Defunct
1	NDSBTest	5955	5971	Defunct
2	NDSBTest	5956	5972	Defunct
3	NDSBTest	5957	5973	Defunct
1	FarDet	5951	5981	Operational
2	FarDet	5952	5982	Operational
3	FarDet	5953	5983	Operational
1	NearDet	5951	5991	Operational
2	NearDet	5952	5992	Operational
3	NearDet	5953	5993	Operational
1	NearGateway	5902	????	Operational

Example¶

EXPERTS ONLY
On Windows, using RealVNC Viewer (renamed to vncviewer.exe), MIT Kerberos for Windows, and plink; the following batch file (FarDet1.bat) connects to the first screen of the Far Detector:
Start plink -ssh -L 5981:localhost:5981 <Principal>@<Gateway> "ssh -L 5981:localhost:5951 -N novacr01@novadaq-far-master-02.fnal.gov"
pause
start vncviewer -Shared -passwd passwd localhost:81

passwd is a file with the MD5'd VNC viewer password, and <Gateway> is a machine connected to the Fermilab network accessible from the outside. Using the tables above, it is possible to connect to any detector/station combination.