Chris, Carlos, Jonathan, Jim, Dave:

today we installed Chris' medm_time_machine software on the CDS workstations. This permits the user to ask how an MEDM screen looked like in the past, provided the channel data is available from the selected NDS server.

To open the feature, right-mouse inside an MEDM and select Execute (last item) and TimeMachine (last item on pull-out window). See figure 1.

As an example, H1 was locked at noon today and is currently unlocked due to an earthquake. Figure 2 is requesting the OMC DC-PDA filter module screen at noon (5 hours and 30 minutes ago at the time of asking). Figure 3 shows the current running MEDM on top, and the timewarped screen from 12:02 PDT today below it. The time strings in the upper right corner show the times. Channels which are not in the DAQ show up as white rectangles (for example strings, momentary buttons, redundent outputs). When the IFO was locked, the input was many thousands of counts.

One feature we added to the launcher today was to allow the user to set the precision of the playback data. In some screens a precision of 3 is good, for others lower precision makes the screen more readable.

Jonathan showed that by changing the NDSSERVER enviromnent setting and opening a kerberos ticket, this system is able to get data from the LDAS NDS2 server.

Things to note:

• This is a H1 only system, it does not handle H0 channels
• The default is to use the local CDS NDS server, which only has a lookback of 8 days. For more lookback, please use an NDS2 server