1 Time-stamp: <23 Jun 2007 12:37:13 CEST by Sebastian Schaetzel> 2 This document can be found at http://www.desy.de/~sschaetz/hcal/tb-cern/ 3 4 0. Get familiar with the CMB 5 6 look at the picture at http://www.desy.de/~sschaetz/hcal/tb-cern/cmb.jpg 7 8 LED numbering: top LED is LED 0, counting down to LED 11; 9 lowest LED on upper CMB half is LED 8, LEDs 9 to 11 are on lower half 10 11 1. Include module in DAQ 12 13 edit AHC.cfg, set hold for CM to 100 ticks 14 switch LV on 15 startUp 16 runStart -t ahcCmLed -w 17 18 2. Check Tcalib signal at module connector (5 minutes) 19 20 use scope with probes 21 22 Tcalib=4th connector hole from bottom, right position should switch to 23 higher voltage for approximately 1 microsecond 24 25 Vcalib=3rd connector hole from bottom, right position should have positive level 26 27 3. CMB installation (10 minutes) 28 29 get a new CMB 30 31 Check jumper settings for CAN bus behaviour 32 2 jumpers near the blue dip switch: 33 J011: centre pin must be connected with left pin (o-o o), or 34 jumper fully open (o o o) 35 J01(hole): centre pin must be connected with right pin (o o-o), 36 or jumper fully open 37 38 CAN bus position and address 39 Every CMB needs a unique CAN bus address; it is set with the 40 blue dip switches (only the rightmost 8 switches are used) 41 42 Convention: the CAN bus address is set to the number 43 of the module to which the CMB is attached. 44 45 physically readjust LEDs and PIN diodes so that they stick out 46 through the holes of the CMB housing by the same length 47 48 switch off CMB voltage (at Slow Control) 49 50 switch off SiPM HBAB high and low voltage (at Slow Control) 51 52 mount the CMB physically to the module 53 use the four brass screw connectors as guidance 54 55 the LEDs generally fit well into the holes, be careful about the 56 PIN diodes. For some CMBs it helps to lift the CMB up a little 57 when pushing it (gently!) towards the module. 58 59 tighten the four screws at the outer part of the housing 60 61 connect the PIN diode readout cable ***ESSENTIAL*** 62 The two PIN diode read-out HBABs are located on top of the 63 module stack. Connect a PIN diode read-out cable to the CMB. 64 Put the cable number in the AHC.cfg file. (There is a script 65 which uses AHC.cfg as an input and creates the correct mapping 66 of the PIN diodes in the HCAL database.) 67 68 The PIN diode read-out cable is NEEDED to equalise the grounding 69 of CMB and HBAB! Do not switch on the module LV without having 70 connected the PIN cable or unless you have equalised the ground 71 by other means! Different grounds can destroy the 72 V_calib/T_calib sender on the SiPM HBAB. 73 74 connect the CMB power cable 75 use the power connector which has the same number as the CAN bus position 76 connect it to the connector on the top side of the CMB which is 77 away from the module 78 79 connect the CAN bus cable 80 "Daisy chain": the CAN bus is guided through the 81 CMBs. Make sure the chain is not interrupted. The CAN 82 bus must be terminated after the last CMB with 83 a termination adaptor. 84 85 switch on the SiPM HBAB low voltage 86 87 switch on the CMB voltage 88 89 Test the CAN bus connection 90 click "CHECK" button on Slow Control CMB main panel 91 92 recognised CMBs (labeled according to the CAN bus position) 93 appear green; check if newly connected CMB is seen 94 if not, check dip switch settings, CAN cabling, jumper settings 95 96 4. Check LED position and width (20 minutes) 97 98 start LED run: runStart -t ahcCmLed -w 99 100 set the LED amplitude from the Slow Control 101 detailed CMB panel, press "Ampl DAC, width DAC" button in 102 "Pulser settings" box 103 104 enter 255 in the amplitude field 105 enter 120 in the width field 106 107 DAQ Vcalib value is ignored now 108 109 make sure all LEDs are enabled (yellow button) 110 111 connect scope 112 use probes and check that they are connected with 1MOhms termination 113 114 The single vertical pins on the CMB provide the CMB ground; 115 connect the probe ground to one of these pins. 116 117 connect probe to Tcalib at connector from module (fourth pin 118 from below), use start of Tcalib as trigger (rising edge) 119 120 connect two other probes to the two legs of one LED 121 subtract the two LED signals with the scope MATH function 122 such that resulting signal is positive for the pulse 123 124 Measure the delay of Tcalib to LED pulse (the red MATH result 125 of subtracting the two signals at the legs): 126 - press the zoom button on the scope (magnifying glass), screen will divide 127 - use horizontal position knob to bring the red pulse to the centre 128 (press "coarse" button for coarser steps) 129 - adjust the horizontal scale to 10ns per division 130 - at the bottom of the screen, the time between the trigger 131 and the centre of the screen is displayed. 132 put this number in a table: 133 134 LED 0 1 2 .... 11 135 delay (ns) 136 width (ns) 137 138 The delay is in the range of 110-160 ns. 139 The delay difference between channels must not be 140 greater than 5ns. If it is greater, ask Ivo Polak to readjust 141 the delay. 142 143 Also note the width of the red signal in the table. Adjust 144 to 10ns if necessary according to the following procedure: 145 146 Ajusting LED pulse width: 147 The width common to all LEDs is send via the CAN bus 148 from the Slow Control (the field that was set to 120). 149 150 To adjust the width individually for every LED, use 151 the second trimmer (the one on the right when the CMB 152 is laying in front of you). Turn clockwise to increase width. 153 Adjust to 10ns at FWHM of the red curve on the scope. 154 Note that the red curve is negative before the actual pulse. 155 156 Caveat: For some CMBs, the range in pulse width that 157 can be covered with the trimmer is different. It might 158 not be possible to adjust all CMBs to 10ns for the 120 159 DAC width sent from the Slow Control. You then have to 160 experiment with the DAC width, or ask Ivo Polak to 161 equalise the range. 162 163 Disconnect the LED leg probes, keep the Tcalib trigger 164 165 5. SiPM Calibration mode hold scan (10 minutes) 166 167 connect scope to analogue out of one SiPM HAB 168 switch scope to non-zoom mode 169 170 switch on SiPM HV for the modules that have the DAC settings loaded 171 (=the ones activated in AHC.cfg) 172 173 runStart -t ahcCmLed -w 174 175 Adjust the LED amplitude from the Slow Control such that the SiPM 176 signal is not saturated 177 178 runStart -t ahcCmLedHoldScan -v 25 179 180 ahcBinHst +H -s 5 -f 10000000 320275 (adjust slot, FE and run number) 181 ^ 182 hold 183 mode 184 185 186 start ROOT in the same directory, enter ".x holdMulti.c(0)" at ROOT 187 prompt, the argument is the FE. 188 Find the hold from the printed messages and put it to 189 AHC.cfg. Also change Vcalib for Calib.Mode to 42000 (28000 for the 190 second CMB series (CMBs>20)) in AHC.cfg. 191 192 Activate the new Vcalib value: 193 shutDown 194 startUp 195 196 6. Tuning of LED amplitudes (1.5 hours) 197 198 runStart -t ahcCmLed -w 199 200 activate DAQ Vcalib: activate "Ampl Vcalib, width DAC" on Slow Control 201 202 adjust scope horizontal range to see multiplexed SiPM signal 203 activate mean measurement 204 set gating to vertical cursors 205 activate averaging over 128 triggers in the "Acquire" menu. 206 207 use first trimmer to adjust LED intensity: counter-clockwise 208 increases amplitude 209 210 The cursors are used to select the channels which enter the mean calculation. 211 Increase the LED intensity and see which channels belong to the LED 212 that is currently trimmed; adjust gate accordingly. 213 214 Decrease the LED intensity to a mean pedestal value. 215 Increase the LED intensity so that the mean is slightly higher than 216 the pedestal. Typical mean pedestal values are in the range of 217 30-150mV. Mean values where single pixels can be seen are typically 218 25-80mV higher than the pedestal mean. You have to experiment. 219 To check if the setting is correct, take a run with 8000 events: 220 221 runStart -t ahcCmLed -e 8000 222 223 Convert the binary file to a ROOT file and move to LED analysis directory: 224 Example (you might have to adapt the analysis directory): 225 ahcBinHst -s 5 -f 10000000 320275 226 mv allChannels.root ~/analysis/LEDanalysis/data/allChannels_slot5_fe0.root 227 228 Analyse the data: 229 start ROOT in ~/analysis/LEDanalysis 230 231 use analyse(...) to analyse a single LED 232 the syntax is displayed when starting ROOT 233 234 The light setting is fine when the first 235 three peaks (0, 1 and 2 pixels) are at 236 approximately the same amplitude. 237 238 Readjust the amplitude using the trimmer if necessary 239 When done with this LED connect analogue out cable to next 240 HAB and tune the next LED. Note: the pattern for the coarse 241 modules is (see the file LED2chan_coarse.dat in the LED analysis 242 directory, format: chip chan LED): 243 244 LED HAB 245 0 0 246 1 1 247 2 2 248 7 3 249 8 8 250 9 9 251 10 10 252 11 11 253 254 When done with all LEDs take a run with 30k events and use 255 loop(...) in ROOT to produce a postscript file in the ps 256 subdirectory with all SiPM spectra. Check the peaks and readjust if 257 necessary. 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276
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