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

 Parameter information about Slave-1 : 0x207
 Parameter information about Slave-2 : 0x208
 Parameter information about Slave-3 : 0x209

 Scaler module 3801 in ROC2 : 0x210 

 redundant, if an event type different from defined values is encountered : 0x211

Structure inside Parameter info sub-bank

 0x207: parameter information about slave-1
 0x208: parameter information about slave-2
 0x209: parameter information about slave-3

Each sub-bank has nine words, each 32 bit in the following order

Identifier beginning word
Firmware Revision Number
A mask
B mask
D mask
E mask
PWTL(8 bits) | PWDL(8 bits) | HOLDOFF(8 bits) | PL_Delay(8 bits)
Rejection Width(16 bits) | Accum trigger condition(8 bits) | Event trigger condition(8 bits)
Identifier ending word

The respective slave identifier words are:

 slave #    beginning         ending
 slave 1    0xb1000000       0xb100000f 
 slave 2    0xb2000000       0xb200000f 
 slave 3    0xb3000000       0xb300000f 

As a visual example, the sub-bank parameter information as saved in run # 4042(taken Feb 2011) is shown in the following image.

Structure inside Accumulation sub-bank

The accumulation data from electron detector goes into three sub-banks

 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. Each word has 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

The words are organized in order of increasing strips. For example in the following snapshot displaying data from bank 0x205(slave-2)

1st word has accumulation data of strip-1,
2nd word has accumulation data of strip-2,
... and so on

For this run, a dummy input was given to pin numbers which correspond to strip # 1, 3 and 5 of patch-2 at a rate of 2.4kHz, the MPS was @1 kHz.

One can see 32 words, because each bank has information from each slave. Each slave carries information of 32 strips from all 4 planes.

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.