Log entry time 01:54:25 on February 20, 2006

Entry number 162852

These data were take using a 1.2 kHz pulser as the only trigger source. The pulser input I was using generates both a T3 (fake-coincidence) and a T7 on each event.

There was zero deadtime at 1.2 kHz with both the Gen and GeN_ped configurations. Note the data rate rose from 2.5 to 7 MB/sec when pedestal suppression was disabled. Run 1896 had the same inputs but I changed the prescaling so the TS saw the pulser as T3s instead of T7s (I was a little worried that the deadtime formula wasn't looking at T7s).

Run#    Pulser  Config  DAQ     DT      DataRate
        (kHz)           (kHz)   (%)     (MB/s)
## All triggers prescaled out (psN=999999) but the pulser (ps7=1)
1894    1.2     Gen     1.2     0       2.5
1895    1.2     Gen_ped 1.2     0       7
1896    1.2     Gen_ped 1.2     0       7       changed to ps3=1, ps7=10000

These data show the effect of ramping up the pulser rate and seeing what happens using the GeN and GeN_buffered configurations. See Figure 1 too.

With GeN, dead-time jumps up very quickly at around 3 KHz, but ramps up even earlier with the buffered mode...not sure I understand that.

Run#    Pulser  Config  DAQ     DT      DataRate
        (kHz)           (kHz)   (%)     (MB/s)
## All triggers prescaled out (psN=999999, ps7=10^4) but the
pulser-driven T3 (ps3=1)
1897    1.2     Gen     1.2     0       2.5
        2.4     Gen     2.4     0       5
1898    5.6     Gen     2.7     50      5
        3.6     Gen     1.8     49      4.8
        2.6     Gen     2.4     1       4.9
        3.4     Gen     2.4     21      5

1899    4.4     Gen_buff        2.0     57      4
        2.9     Gen_buff        1.9     34      4
        2.0     Gen_buff        1.9     7       3.9
        1.4     Gen_buff        1.4     0       2.9

This last set of data was taken using real triggers to see how the three DAQ read-out configurations compared when modules were actually seeing data on their inputs. Gen_buffer performed much better in this test.

## Trigger with real singles (actual data)
## T1=1.3 kHz, T2=200 Hz, T3=8 Hz
## ps1=1,ps2=,ps3=1
## NOTE: I missed the '1' for ps2, so I expect it was prescaled to zero.
## Total rate INTO the TS was ~1.5kHz (T1+T2+T3), or ~1.3 kHz (T1+T3).
##    The 1.3 kHz makes the most sense with the data below.
Run#    Config      DAQ     DT      DataRate
                    (kHz)   (%)     (MB/s)
1900    Gen         1.0     30      2.2
1901    Gen_buff    1.16    18      2.2
1902    Gen_ped     0.93    35      5.7

Figure 1