Media: fiber optic, GLINK
Record Length: variable

19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
VRB START				Header Length								#Objects
				Header Format			Object Format					Object Length
				Tick								Data Type
				Turn
				Link Status word 1
				Link Status word 0
				Cluster Object(s)
				Data Type								Tick
				Vertical Parity
				Pad Frame(s)
VRB END

Field Definitions

note: empty cells will contain zeros

VRB START = "0101"

Header Length = 0x03

#Objects = the number of Track Objects, range 0-46

Header Format = Header Format, "001"

Object Format = Object format, "00001"

Tick = The accelerator bunch crossing number

Data Type = varies with sextant: STSX0 = 0xB5; STSX1 = 0xB6; STSX2 = 0xB7; STSX3 = 0xB8; STSX4 = 0xB9; STSX5 = 0xBA

Turn = The accelerator turn (revolution) number

Link Status word 1 =

   [15:14] "00"
   [13:4]  Link Parity Errors (bit 13 = link9, bit 12 = link8, ... bit 4 = link0)
   [3:0]   Tick/Turn Errors (bit 3 = link9, bit 2 = link8, ... bit 0 = link6)

Link Status word 0 =

   [15:10] Tick/Turn Errors (bit 15 = link5, bit 14 = link4, ... bit 10 = link0)
   [9:0]   Link Error (bit 9 = link9, bit 8 = link8, ... bit 0 = link0)

Cluster Objects are 32 bits long, which requires two frames in this record.
Bits [31:16] go into the first frame and bits [15:0] go into the second frame. The 32 bits are defined as:

   [31]     Track curvature
   [30:29]  Track PT bin ("00" = Max, "01" = High, "10" = Medium, "11" = Low)
   [28:26]  Extended PT
   [25]     Set to indicate that a CPS cluster matched to this track
   [24]     Loose CPS cluster association not supported, "0"
   [23:21]  error code, unused.  always "000"
   [20]     Set to indicate that the track matched to a CPS cluster outside the home sector
   [19:16]  Relative address of the CPS cluster centroid, range 0-15
   [15:10]  Track Phi value, range 1-44
   [9]      Set to indicate an isolated track
   [8]      "0"
   [7]      Duplicate track bit.  Set to indicate that the upstream STOV has sent this track
            to two neighbouring STSX boards.
   [6:0]    Trigger sector number, range 0-79

Vertical Parity

Pad Frame(s) = Pad frames are inserted to insure that the total record length is a multiple of 8 frames.
This requirement is imposed by the VRB hardware.

VRB END = "1010"

Revision History

3 November 2005: created JTO

2 December 2005: corrections from Thei. Change max number of objects to 46. update cluster object definition for bits [23:21]. Added definitions for Link Status words, removed firmware revision fields.

3 January 2006: add parity links