Specifications for Database Additions for NLCTA/8Pack Structure Summary Display


Janice Nelson

10 March 2004


New PVs needed for Summary Display and possible names

10 second updates are sufficient for all


1.      3 Run Times showing how long since each of the Stations’ has been running since the fault counters were reset in hours (now – then) to 2 decimal places.  10 sec updates are good.
To ascertain “running” status, we want the counter loop to watch the VTOP PVs (see #3 below) and increment when they are above a user-enterable threshhold.
maybe TRS(1,2,8):AS:FLT:RUNTHRESH for the threshhold?

2.      Trip rate (faults/hr) for each of 8 structures: TRS1:AS1 and AS2, TRS2:AS1 and AS2, and TRS8:AS5, AS6, AS7, and AS8 defined as # of missing energy faults (since last reset) divided by the run time for that structure’s station (hrs since last reset above).
10 second updates is good.
Current PV names for # of missing energy faults are:
TRS(1,2):AS:FAULT:COUNT.(G,I) (I’m not sure how Ron will configure 8-pack’s loop.)
Name maybe TRS(1,2,8):ASn:FAULT:COUNTRATE ?

3.      Gradient (MV/m) for each of the 8 structures.  Equation is:

Where VTOP is from the peakpower meter, Pcal is a user enterable calibration constant, Pn is user enterable power at a given gradient, n is that gradient (also user enterable), and Eacc is the gradient we want to calculate.  We’ll need 8 each: Pcal, Pn and n.  Corresponding VTOPS are:
Updates every 10 seconds is good.
Name possibilities:
TRS(1,2,8):ASn:GRAD:PCAL, :PGRAD, :NGRAD with answer going into :EACC

4.      Total energy gain in MeV – sum of the 8 gradients (EACCs) times 0.6 (the length of the structures in meters) Final answer into TRS:AS:GRAD:EACC? (For several months now we’ve had only 60 cm structures installed which is the planned length for NLC structures.  Given this, it doesn’t seem necessary to have a variable (8 total) for each structure’s length.)

5.      Average Gradient (MV/m) PV from #4 (TRS:AS:GRAD:EACC) divided by 8 (number of structures)  TRS:AS:GRAD:EACCAVE ? (Need to differentiate average from total.)

6.      Average rate: time weighted average of the 8 rates (purple) (#2 above).  ans = sum of trips divided by sum of runtimes.  (This is the same as each rate times the run time divided by the sum of the runtimes.)  (TRS:AS:FAULT:AVERATE)

7.      Text PVs for each structure’s name.  Can’t imagine needing anymore than 20 characters for each. (TRS(1,2,8):AS(1,2,5,6,7,8):STRUCT:NAME – 8 total)



When needed: it would be nice to watch it for a few weeks before the ITRP committee come, about April 5th, to make sure it’s all that we need and give Janice time to modify the display to meet everyone’s requests.


Lower priority:

CUD – not too hard, Janice has to convert DM to dm2k.

WEB? Has to be displayed in foreground (and constant size) on the same monitor all the time. (Jingchen)