Output data structure in CODA
The electron detector readout boards(v1495) are currently outputting data in the following format:
Event types defined
Event type 1 : Helicity Reversal events Event type 2 : photon single events Event type 3 : electron single events Event type 4 : coincidence of electron and photon single events
Sub banks used
Single Event Data from Slave-1: 0x201 Single Event Data from Slave-2: 0x202 Single Event Data from Slave-3: 0x203
Accumulation Data from Slave-1 : 0x204 Accumulation Data from Slave-2 : 0x205 Accumulation Data from Slave-3 : 0x206
If the TS2 did not receive either of the type-1 or type-4 triggers then the message logger will start printing "Event type and number are:" followed by the value assigned to the variable event_ty
Structure inside Accumulation sub-bank
The accumulation data from electron detector goes into three sub-banks in the following
0x204: accumulation from slave-1 0x205: accumulation from slave-2 0x206: accumulation from slave-3
Each sub-bank has thirty-two words of 32 bits in the following format.
Most significant byte(bits 32-23): no.of hits in plane-1 Next significant byte(bits 24-17): no.of hits in plane-2 Next significant byte(bits 16-09): no.of hits in plane-3 Least significant byte(bits 01-08): no.of hits in plane-4
Structure inside single-event subbank
The single event data from electron detector goes into three subbank
0x201: singles from slave-1 0x202: singles from slave-2 0x203: singles from slave-3
Each sub-bank has five 32 bit words in the following format.
1st word: hit-map on plane-1 for strip 1 through 32 2nd word: hit-map on plane-2 for strip 1 through 32 3rd word: hit-map on plane-3 for strip 1 through 32 4th word: hit-map on plane-4 for strip 1 through 32 5th word: (some redundant information) 0x00000(20 bits) | Helicity(1 bit) | raw_trig_CNT (11 bits)
Following is a snapshot of the data bank as seen through xcefdmp.
Details:
- The above snapshot displays the 32 bits in hexadecimal format. In the first 4 words, the least significant bit represent hit-information of strip-1 for all the 4 planes.
- Successively, the higher order bits represent hit-information for each next strip. Thus the 32 bits word has the hit-information of the 32 strips in this patch of data.
- The 5th word (currently) has the information whether this data correspond to positive or negative helicity. followed by the total number of trigger that were received during the previous helicity period.
- (I intend to add the buffer status in the 5th word, which now has zero's)
Similarly, data from s2 and s3 contains the hit map of strip 33-64 and 65-96 on all planes respectively in the above order.
This pattern can be changed with ease, but this is the format in which the most recent data files are found.
