List of Digital Optical Module Data Acquisition Goals/Features |
Status |
| Local coincidence in the ice (Not a high priority with the AMANDA collaboration) | Achieved |
| Download system boot PROM and boot from it | Achieved |
| Download and run CPU program | Achieved |
| Download FPGA configuraton file, load and run from it | Achieved |
| Time-stamp PMT events to precision better than 5 ns relative to other DOMs | Achieved |
| Time-stamp PMT events to a precision of better than 5 ns relative to UT (Note 1) | see note |
| Sending to the surface a hit packet for every PMT hit; Hit packet time accuracy of 30 ns (Note 2) | see note |
| Next nearest neighbor local coincidence signaling (Note 2) | see note |
| Full speed data transmission at a rate of 600 Kilobaud (Note 3) | see note |
| 200 PE linear amplitude range (Note 4) | see note |
| Observe down-going muons | Achieved |
| Communicate control, telemetry and test data packets through the CPU UART in the DOM | Achieved |
| Test lookback memory | Achieved |
| Store events to lookback memory | |
| Retrieve events from lookback memory and send to surface | |
| Store hit packets in lookback memory | |
| Retrieve hit packets from lookback memory and send to surface | |
| Event compression | |
| SPE event feature extraction | |
| Communicate control and telemetry packets through the DOM FPGA to communications ADC and DAC | |
| Communicate control, telemetry and data packets through the surface FPGA to the computer bus |
Note 1. The clock distribution system for string 18 readout should allow 5 ns or better synchronization to UT
Note 2. It may be possible in the coming months to demonstrate this feature with the 'demonstration DAQ' currently operating at the south pole. The success depends on the will and support of the collaboration since lack of resources here at LBL affects priority and level of effort.
Note 3. In January, 2001, simulation high speed data was sent from a DOM in the ice to surface electronics at the south pole. Captured waveforms indicate a very comfortable signal to noise ratio, and signal amplitude at speed in excess of 600 kilobaud. Effort to achieve this goal is high on the priority list, but behind several current priorities.
Note 4. A complicated compromise made in the last week of November, 2000 prevented this demonstration. The compromise was struck because the PMTs used would not deliver an acceptable peak to valley ratio if operated at a gain consistent with setting the maximum range of the DOM at 200 PE. This demonstration will be possible in the lab when a PMT better matched to the high input sensitivity of the DOM is available for testing. A 50 PE peak amplitude is substantially demonstrated.
Compiled by Gerald Przybyloski, Lawrence Berkeley National Laboratory, May 16, 2001