10 1 1 255 255 255 64 64with "GS+EXT" main and late on and all others off on the "MTM Status and Control" screen. On the "pretrigger logic" screen "ext OR mask" should be on and everything else off.
The two relevant EPICS screens should look as:
In addition to the overlapped particle/GS pretrigger signals, which is the main external pretrigger signal, there is also a scaled down particle singles signal or-ed to the final external pretrigger signal feed to the MTM.
cesd 03100000 8000 22 4741 4D4D 4153 5048 4552 4521 03100010 33E 16E 9FB B5F 0 27 0 0 03100020 6401 8800 6402 34DE 6403 8801 6404 4BB 03100030 6405 8802 6406 3002 6407 A010 6408 9 03100040 6409 1003 640A 33C7 640B 3C43 640C 9811 03100050 640D 3ED 640E BA3 640F 6005 6410 9812 03100060 6411 8 6412 1008 6413 5009 40 8181 03100070 40 8181 40 8181 D2D 0 0 A 03100080 57BE 1101 0 0 FFFF FFFF 8000 21 03100090 4741 4D4D 4153 5048 4552 4521 366 134 031000A0 8C1 B07 86 5D 0 0 6401 8800 031000B0 6402 2C9D 6403 8802 6404 3002 6405 B810 031000C0 6406 A 6407 1004 6408 2216 6409 2D54 031000D0 640A 3008 640B 764F 640C 7BD5 640D 8811 031000E0 640E 6005 640F 9812 6410 8 6411 1008 031000F0 6412 5009 40 8181 40 8181 40 8181 03100100 D9D 0 0 A 57BE 1941 0 0 03100110 FFFF FFFF 8000 21 4741 4D4D 4153 5048 03100120 4552 4521 464 15A 992 B48 0 5A 03100130 0 0 6401 8800 6402 74A6 6403 8802 03100140 6404 3002 6405 B810 6406 9 6407 1003 03100150 6408 267B 6409 2B45 640A 3009 640B 727F 03100160 640C 7CF3 640D 8811 640E 6004 640F 9812 03100170 6410 9 6411 1008 6412 5009 60 8181 03100180 60 8181 60 8181 AE9 0 0 A value = 1 = 0x1If you are paranoid, you will want to stop the eff before you do this to avoid having part of the memory overwritten while you look at it. If the memory is updated while you dump, you may see parts of events and become confused. Note: it's a hex dump!
The format of this raw CES memory data is documented here. Here is a quick walk-through of the above example:
trailer-1: 40 pre : bit 6 set in MTM 8181 pre : ?? 40 main: bit 6 set in MTM 8181 main: ?? 40 late: bit 6 set in MTM 8181 late: ?? D2D 0 TAC2 (RF was not connected in this case) Note: I think something is not right in the header file for trailer 1. There is more than I what the header file suggests. trailer-2: 0 user programmable word 1 A trigger time ttH 57BE trigger time ttM 1101 trigger time ttH 0 user programmable word 2 0 user programmable word 3 FFFF event separator FFFF event separator
03100010 33E 16E 9FB B5F 0 27 0 0 33E ge high res energy 16E bgo hit pattern and detector ID (det 110 in this case), bit # 8 is the ge-bit, it should always be 1 for clean data. The upper bits are zero since the BGOs did not fire and give a bit patterns. 9FB trap signal B5F ge time 0 side energy 27 ge low res signal 0 bgo energy 0 bgo timeI.e, only detector 110 fired in this example.
bit 31: always zero bit 30: error bit bits 29-26: dip switch setting bits 25-16: FERA word counterin this case we always see the "64nn" as the first part of the 32 bit FERA word and then follows the real FERA data/header word. From the last FERA word we can see that 0x13=19 FERA words were read out. We can also see that the error bit is set (I don't know why!?) and that the timeout switch setting is set to "1001" which is a timeout of about 30usec.
8800 VSN=0, WC=1 34DE channel 6, data: 0x4DE 8801 VSN=1, WC=1 4BB channel 16, data: 0x4BB 8802 VSN=2, WC=1 3002 channel 6, data: 0x2 A010 VSN=16,WC=4 9 channel 16, data: 0x9 1003 channel 2, data: 0x3 33C7 channel 6, data: 0x3C7 3C43 channel 7, data: 0x443 9811 VSN=17 ,WC=3 3ED BA3 6005 9812 VSN=18, WC=3 8 1008 5009(The FERA data interpretation has not been double checked). Notice that normally the VSN numbers are loaded so that the VSN numbers have to increase as read out so we can check consistency. Likewise, the channel numbers should come out in order (except 16 which comes out as a zero). The FERA header words are recognizable by their 88xx and 89xx values. Remember that for 11 bit FERAs the data goes from 0-->1919. Overflow is 2047.
Here is a quick run down of the FERA data format as it will look when we use ECL readout.