Notes on the Mapping of (FEC, STRING, CHANNEL) to (SENSOR, ROW, COL)

(Updated Jun 19/98)

Notes on the Mapping of (FEC, String, Channel) to (Sensor, Row, Col)

The NEW general structure of the table is as follows:

GEO_SENSOR	SENSOR_TYPE	FEC_ID	FEC_STRING	CHANNEL	SENSOR_ROW	SENSOR_COL	BONDING_PAT	PAD	SENSOR_POS	POSITION_FLAG	WURST_ID	WURST_READ_POS	HYBRID_POS	MOD_TYPEP
NA00		0		0	1	2	0	0	1	1	1	0	L	Mod1
NA00		0		1	1	3	0	1	1	1	1	0	L	Mod1
NA00		0		2	1	4	0	2	1	1	1	0	L	Mod1

and so on for a total of 54144 channels across 16 FEC's controlling the spectrometer.

The ROOT-compatible printf()/scanf() format for each line in this table is :

printf("%s %3d %3d %3d %3d %3d %3d %3d %3d %3d %3d %3d %3d %s %s\n", geo_sensor, sensor_type, fec_id, fec_string, channel, newrow, newcol, bond_pat, pad, sensor_pos, pos_flag, wurst_id, wurst_read_pos, hybrid_pos, mod_type);

The CHANNEL column denotes the Channel number within the current string, PAD denotes the channel number within the current chip. See below for an explanation of the POSITION_FLAG.

The sensor types are: Spectrometer : 1 to 5 Octagon : 6, Inner Vertex : 7, Outer Vertex : 8

In addition, the following convention is followed for "special pads":

(Column,Row)
(-1, -1)  unconnected
(-1, -2)  connected through a capacitor to the Guard ring
(-1, -3)  connected to a dummy pad

The unconnected pads on the octagon sensors are 0,1,2,63,94,125,126 and127.

Bond Pat : 0   Pad 0: unconnected
Bond Pat : 0   Pad 1: connected through a capacitor to the Guard ring.
Bond Pat : 0   Pad 2: connected to a dummy pad
Bond Pat : 0   Pad 63: unconnected
Bond Pat : 0   Pad 94: unconnected
Bond Pat : 0   Pad 125: connected to a dummy pad
Bond Pat : 0   Pad 126: connected through a capacitor to the Guard ring.
Bond Pat : 0   Pad 127: unconnected

The unconnected pads on the Spectrometer Type 2 sensors are:

Bond Pat : 0   Pad 0: unconnected
Bond Pat : 0   Pad 1: unconnected
Bond Pat : 0   Pad 2: unconnected

Bond Pat : 2   Pad 0: unconnected
Bond Pat : 2   Pad 1: unconnected
Bond Pat : 2   Pad 2: unconnected

Bond Pat : 4   Pad 0: unconnected
Bond Pat : 4   Pad 1: unconnected
Bond Pat : 4   Pad 2: unconnected

Bond Pat : 6   Pad 0: unconnected
Bond Pat : 6   Pad 1: unconnected
Bond Pat : 6   Pad 2: unconnected

The allotment of FEC's to the frames in the PHOBOS spectrometer and their corresponding modules is done according to Mark Baker's prescription. In brief, each FEC can have a maximum of 4096 channels and each string in an FEC can have a maximum of 768 channels:

FEC's 0 - 15 : Spectrometer modules (Negative Arm) - Allotment of FEC's to specific spectrometer modules is by Mark Baker's "quick and dirty" prescription. This is completely ad-hoc and changeable.

FEC's 16 - 31 : Reserved for Spectrometer modules (Positive Arm)

FEC's 32,33 : Octagon Region 1 and 3 respectively. Each handles 4096 channels (i.e. 4 PC boards).

FEC's 34,35 : Octagon Region 2. Each handles 2560 channels - (i.e. 2 PC boards) - quite wasteful, but will be changed!

The Spectrometer FEC's control the Negative arm of the spectrometer. So FEC_ID = 0 to FEC_ID = 7 are the on bottom-side and FEC_ID = 8 to FEC_ID = 15 are on the top-side.

the various naming conventions on all Spectrometer module types are (as prescibed by Heinz):

                         0 wurst         1 wurst
                XX---------------------------------------
        Flex C  XX                           bpa=4 5 6 7      L hybrid position
                XX---------------------------------------
                  |00      |00       |00       |00      |
                  |        |         |         |        |
                  | Sens 0 |         |         | Sens 3 |
                  |        |         |         |        |
                  |        |         |         |        |
                  |        |         |         |        |
                XX---------------------------------------
        Flex C  XX                           bpa=3 2 1 0      R hybrid position
                XX---------------------------------------

                        1 wurst         0 wurst

(and similar for other modules with fewer sensors/hybrids/chips)

NEW: Note that in the above diagram (Row=0,Col=0) is defined in the reference frame of the MODULE. While mounting modules on frames, the module orientation changes, and so the (Row=0,Col=0) point changes. To take this into account, we have defined the following 'POSITION_FLAG's for the spectrometer modules:

POSITION_FLAG = 1 POSITION_FLAG = -2

(Chip-side is facing you) (Chip-side is facing you)

           XX--------------------                  --------------------XX
           XX--------------------                  --------------------XX
             |   |   |   |   |                     |   |   |   |   |
           XX--------------------                  --------------------XX
           XX--------------------                  --------------------XX

           OO--------------------                  --------------------OO
           OO--------------------                  --------------------OO
             |   |   |   |   |                     |   |   |   |   |
           OO--------------------                  --------------------OO
           OO--------------------                  --------------------OO

POSITION_FLAG = -1 POSITION_FLAG = 2

(Chip-side is on the back) (Chip-side is on the back)

         These orientations are as viewed FROM the origin, looking outward towards the Spectrometer Negative Arm.

	Note that this POSITION_FLAG is for internal book-keeping only. The New FEC_TO_SENSOR map

	available for download here, already takes care of these orientations and presents the (ROW, COL) in

	the PHAT convention!

For the Octagon modules the naming conventions and readout schemes are:(as prescribed by Alan Wuosmaa)

(Special note: for the purpose of assembly and readout, we regard each PC board as a single module with various chips and sensors sitting on it. We keep track of the individual Octagon hybrids separately)

Region 1 and 3 : i.e. the sets of octagon planes around the interaction vertex that are NEXT to closest to it.

                <<<<<<<----------  readout in this direction

             --------     --------      --------     --------
             |sens 0|     |sens 1|      |sens 2|     |sens 3|
             |      |     |      |      |      |     |      |
             |wur 1 |     |wur 1 |      |wur 1 |     |wur 1 |
             --------     --------      --------     --------
                |            |             |            |
                |            |             |            | <- ribbon cable
                |            |             |            |
           |--------------------------------------------------|
           |                                                  |
         XX|---XXX----------XXX-----------XXX----------XXX    |
 Flex C  XX|                                                  |   PCB
         XX|---XXX----------XXX-----------XXX----------XXX    |
           |                                                  |
           |--------------------------------------------------|
                |            |             |            |
                |            |             |            |
                |            |             |            |
             --------     --------      --------     --------
             |sens4 |     |sens 5|      |sens 6|     |sens 7|		wurst 0 : 512 chan
             |      |     |      |      |      |     |      |		wurst 1 : 512 chan
             |wur 0 |     |wur 0 |      |wur 0 |     |wur 0 |
             --------     --------      --------     --------

                <<<<<<<----------  readout in this direction

Region 2 : i.e. the sets of octagon planes around the interaction vertex that are CLOSEST to it.

                <<<<<<<----------  readout in this direction

             --------     --------      --------     --------    --------
             |sens 0|     |sens 1|      |sens 2|     |sens 3|    |sens 4|
             |      |     |      |      |      |     |      |    |      |
             |wur 1 |     |wur 1 |      |wur 1 |     |wur 1 |    |wur 0 |
             --------     --------      --------     --------    --------
                |            |             |            |           |
                |            |             |            |           |
                |            |             |            |           |
           |-------------------------------------------------------------|
           |                                                             |
         XX|---XXX----------XXX-----------XXX----------XXX        XXX    |
 Flex C  XX|                                                       |     | PCB
         XX|---XXX----------XXX-----------XXX----------XXX--------XXX    |
           |                                                             |
           |-------------------------------------------------------------|
                |            |             |            |           |
                |            |             |            |           |
                |            |             |            |           |
             --------     --------      --------     --------   --------
             |sens 5|     |sens 6|      |sens 7|     |sens 8|   |sens 9|    wurst 0 : 768 chan
             |      |     |      |      |      |     |      |   |      |    wurst 1 : 512 chan
             |wur 0 |     |wur 0 |      |wur 0 |     |wur 0 |   |wur 0 |
             --------     --------      --------     --------   --------

                <<<<<<<----------  readout in this direction

	Note the special readout sequence for Wurst 0 here : 4 - 9 - 8 - 7 - 6 - 5

	Also note that some of the Octagon Sensors are "missing" to accomodate the Vertex.

(NEW) The Octagon Sensors are named according to the naming convention setup by Adam Trzupek here. There are a total of 12 Sensors "missing" in the Region 2, to accomodate the Vertex Detectors. The (Row , Col) numbers appearing in the map are according to the co-ordinate convention circulated by Mark Baker on the Phobos mailing list, i.e. (nrows = 0 to Max in Increasing Z) and (ncol = 0 to Max in Increasing Phi).

Page Last Modified: June 19/98 Pradeep Sarin