Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter1 Current status of DAQ System Karsten Kötter

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter2 Problems with the DAQS ADC board driven at 16KHz by LIGO timing card does not work at all ("channel swapping" at a rate few/second) ADC board driven at 8KHz reliability problems ("channel swapping" at a rate 1/hour...week) problem very hard to reproduce

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter3 Work done in Hannover (1) central station DCU ("alchemist") "channel swapping" problems could not be solved system worked not reliable for more than approx. one day made hardware modifications, not successful north end station DCU ("thot") no "channel swapping" observed during a two week run could be used to record environmental data

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter4 Work done in Hannover (2) indication of electronic interference problem moved DCU from north end station to central station latest result (after 18h): "thot" failed when located in the central station

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter5 Tests performed in Glasgow (1) east end station DCU shipped to Glasgow to investigate problems more closely goals: better understanding of soft-/hardware understand reason for ADC failure at 16KHz (investigate channel swapping at 8KHz)

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter6 Tests performed in Glasgow (2) hardware ADC tested in all configurations LIGO timing card monitored timing signals software DCU code short and simple software program was written to read and display data from ADC

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter7 Test Results (1) ADC board works OK when running on internal clock (up to 100KHz SF) LIGO timing card produces proper timing signals signals are (almost) identical to signals generated by ADC board in "Master Mode" complies with specifications from LIGO and ICS

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter8 Test Results (2) ADC in "Slave Mode" driven by LIGO timing card did not work with 16KHz SF "channel swapping" on timescales of 100ms works OK with 8KHz SF only few seconds of data could be tested -> reliability unknown

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter9 Test Results (3) attempt to drive one ICS board in "Slave Mode" by another ICS board in "Master Mode" also failed for sampling frequencies above 12KHz problem has to be ADC board, not LIGO timing card

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter10 Test Results (4) ICS supplied us with their driver and software seems to work OK now very recent result, more investigation required the important difference between our code and ICS' code not yet found

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter11 Next Steps investiate reliability in 16KHz mode write long stretches of data to disk and analyse it for "channel swapping" check (long term) timing accuracy further investigation of reliability problem at 8KHz (?) interference (?) software (?)

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter12

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter13 operating modes of ADC board „Master mode“ – internal clock sample clock running on internal oscillator FTC signals generated internally „Master mode“ – external clock sample clock applied by GPS receiver FTC signals generated internally „Slave mode“ sample clock applied by GPS receiver FTC signals applied by LIGO timing card (sync. to GPS second boundary)

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter14 ADC board timing signals

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter15 „Slave Mode“ + LIGO timing card

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter16 „Master Mode“

Max-Planck-Institut für Gravitationsphysik - Albert-Einstein-Institut DC Meeting Golm - Karsten Kötter17 Master mode + additional „timing channel“ record time offset in a channels