CRV DAQ Notes

Board Reader Settings

subruns

Subruns are controlled by fragment id 0. This is set in fragment_id of a board reader. The number of subruns are set through rollover_subrun_interval in the boardreader with fragment id 0. The default is 20000.

Rates (on mu2edaq08)

For this test, data is produced in software. Every 100000 event window tags, 16 bytes if payload are added to link0/block0 data up to 4kB.

reader	builder	logger	board reader	each builders	each logger w/ writing
1	2(x1)	2(x2)	~33kHz	~6kHz	6kHz, up to ~30MB/s (doesn't seem to be the limit)
1	2(x1)	1(x1)	~33kHz	~6kHz	~3kHz, up to ~15MB/s (doesn't seem to be the limit)
1	2(x1)	1(x1)	~33kHz	~6kHz	writing off/art parth still present: ~3kHz, saturations around ~35MB/s (per artjob?)
1	2(x1)	1(x1)	~33kHz	~6kHz	writing/art path off: ~5kHz, got up to ~70MB/s (saturation starts?)
1	2(x2)	2(x2)	~30kHz	~5.5kHz	~5.5kHz, at 40MB/s down to 5kHz, ~70MB/s down to 4.5kHz
1	2(x8)	2(x2)	~30kHz	~6kHz	~6kHz , at 40MB/s down to 5.3kHz, ~70MB/s down to 4.5kHz

HOWTO

See https://github.com/Mu2e/otsdaq_mu2e_crv/wiki/HOWTO Contains:

• leading DTC firmware