Remote viewing of real-time data and trend data

Peter Shawhan, Szabolcs Marka
Revised March 7, 2003

The computers in the control rooms at the LIGO observatory sites are connected to the CDS (Control and Data Systems) network, which is isolated from the Internet. These computers can receive data in near-real-time, via LIGO's "network data server" protocol, as it is collected by the data-acquisition system; this is how Diagnostic Test Tools (DTT) and Data Viewer normally get their data. The data-acquisition system also distributes "recent" raw data (typically the last few days) and "trend" data (second-by-second and minute-by-minute summaries for each channel) on demand.

To permit these data streams to be viewed (using DTT or Data Viewer) from outside of the control rooms, a special "ndsproxy" program is running at each observatory on the computer which forms a gateway between the CDS network and the Internet. This program relays data requests from a client on the Internet to the data-acquisition sytem on the CDS network, and relays the data in the opposite direction. Access is restricted to IP addresses which have been given permission to view the CDS web pages at Hanford, which should be most LSC institutions. Also, you need to have installed LIGOtools, including the dtt and dataviewer packages, which are currently only available for the Solaris operating system.

This capability should be used sparingly, since it places a burden on the LIGO data-acquisition system - and on the limited network bandwidth, if used from off-site.

Instructions

  1. Type dtt to bring up the Diagnostics Test Tools main menu on your local machine.

  2. Under the "File" menu, choose "Setup..."

  3. Click on the radiobutton next to "Server:" and type the name of the machine on which ndsproxy is running, as well as the port number. The following are available:
    ndsproxy addressPortServerDescription
    red.ligo-wa.caltech.edu8088fb0Short look-back, no DMT trends
    red.ligo-wa.caltech.edu8089fb3Long look-back, includes DMT trends
    london.ligo-la.caltech.edu8088llofb0Short look-back, no DMT trends
    london.ligo-la.caltech.edu8089llofb2Long look-back, includes DMT trends
    If you are running dtt on a general-computing machine at the same site as the server, you can just type red or london, respectively.

  4. Click "Ok".

  5. Now, back in the Diagnostics main menu window, click on "Data Viewer", "Fourier Tools", or "Triggered Time Series Measurement". (The other functions are not enabled for remote usage.) With Data Viewer, you can view near-real-time data or use the "playback" function to view "recent" raw data or trend data. "Triggered Time Series Measurement" allows you to view near-real-time data or "recent" raw data using the DTT graphical user interface.

  6. If you are using DTT version 2.0 or later, then the window comes up with the "Input" panel displayed. Click on the circle next to "Online system" to access the NDS server that you specified earlier in this procedure. Then click on the "Measurement" tab to continue.

Notes

Day-by-day usage statistics may be viewed at these links: Hanford, Livingston.

If the ndsproxy program does not seem to be running, or is misbehaving, please contact Peter Shawhan.