33\n The boxes containing the 12 amplifiers are shwon in \ref Figure_FE_board. They are in place
34on the refrigerator. There is no connecting cable at room temperature between the amplifier inputs and the refrigerator inout connector
35and this should minimize the value of the parasitic capacitance,
36useful for the faster detector, and minimize also possible vibration of the missing cable.
37\n There are 2 50-pins ribbons cable that route the connections from the every box to the post front-end board located inside the Faraday cage.
38
39\remark The ribbon cables terminate each with a 50-pins female socket connnector having different color, white and black.
40If the cables are removed from the boxes rememeber to connect the female socket with the corresponding male sockect of the box having the
41same color. The cables are paired and cannot be shared between the boxes.
42
43*\anchor Figure_FE_board
44*\image html Boxes.jpg "Figure_FE_board: Front end boxes on the fridge" width=50%
45*\image latex Boxes.jpg "Figure_FE_board: Front end boxes on the fridge" width=50%
46
47\n When in place, a minimum possible vibration of the boxes could be obtain by using a sponge or some imilar material, \ref Figure_FE_board shows examples.
48
49\note
50- There is no need to remove the sockets if the box is taken from the fridge. Disconnect the box from the refrigerator when necessary. Try to minimize the number of insertions of
51the boxes since the fischer connectors have a limited life time.
52- During operation the shield that cover the ribbon cables should not touch any metal of the fridge. Only the box should be connected
53to the ground of the fridge. See \ref grounding for grounding connection.
54- When the fridge is under maitainance or off, we reccomend to switch to off the front end power supply, see XXXXX for powering,
55or connect the preamplifiers to their internal dummy resistors.
56
57\remark To connect the box to the fridge the white-mark on the female Fischer connector on the refrigerator
58and the red-mark on the black Fischer on connector of the front end box must coincide.
81\n The post front end board and its rack are in the Faraday cage. Cables enters the cage from its side,
82see labels in \ref Figure_faraday_cage_input_cabling.
83\n Two ribbons cables come from each front end box. One output cable, terminated at both sides with a male and a female 25-pins
84D-sub connectors drives the analog signals to the DAQ. One other cable with male and female 9-pins D-sub connectors drives the
85power supplies to the post front end and the front end. It includes: the positive supply voltage, +6.5 V, the negative supply voltage,
86-6.5 V, the digital voltage 5.1 V and the voltage for the detector bias, 0 ÷ 30 V and 0 ÷ -30 V. Note that the ±6.5 V input is
87regulated to ±5 V to the front-end from the power supply regulator in the rack. The last cable is for the
88CAN bus data/command communication between the post front end board and the control PC.
89
90*\anchor Figure_faraday_cage_input_cabling
91*\image html faraday_cage_inpt_cables.jpg "Figure_faraday_cage_input_cabling: Faraday cage input cables to post front end board" width=30%
92*\image latex faraday_cage_inpt_cables.jpg "Figure_faraday_cage_input_cabling: Faraday cage input cables to post front end board" width=30%
93
94\n \ref Figure_post_FE shows the inner of the Farady cage. The rack has the post front end board on its left and the low noise and stable last stage of the
95power supply in the middle. The 9-pins D-sub connector that enters the Farady cage is connected to this last stage of the power supply and a short 9-pin D-sub cable connects
96its regulated output to the post fornt end board.
97\n The CAN-bus cable is connected directely to the post front end board. Between the input cable of the CAN bus to the Faraday cage and the board there is the CAN-bus module, see
98\ref Can_bus_module.
99\n The output from the post front end board is the 25-pins D-sub cable to the DAQ system.
100\n The labels in \ref Figure_post_FE mark where cables have to be connected.
101
102*\anchor Figure_post_FE
103*\image html post_frontend_1.jpg "Figure_post_FE: Post front end board and its stuffs inside the faraday cage" width=30%
104*\image latex post_frontend_1.jpg "Figure_post_FE: Post front end board and its stuffs inside the faraday cage" width=30%
105
106\n
107\n
108
109*\anchor Figure_CAN_bus_module
110*\image html Can_bus_module.jpg "Figure_CAN_bus_module: CAN bus module close to the Faraday cage" width=30%
111*\image latex Can_bus_module.jpg "Figure_CAN_bus_module: CAN bus module close to the Faraday cage" width=30%
116\n Attention must be put to the power supply connections. In \ref Figure_post_FE_FE_PS a picture of the actual etup is shown. On the left, partially shown, there is the filter
117where all the banana cables described in the following anter. The filter has 2 aims. the first is to lower the noise from the commercial power supplies, the second is to protect
118the front end from wrong connections polarity and over voltage sets.
119\n The banana connectors are all red and black and must be connected to the correponding red and black inputs on the power supplies.
120
121\remark Polarities are adjusted inside the filter and the user must connect the banana with color corressponding to the power supplies: red with red and black with black.
122
123\n In \ref Figure_post_FE_FE_PS cables have not yet labels on them, but, at present, labels have been added to help the correspondence.
124There is another way to distinguish them. Every pair of cables is fastened with black platic ties whose number identifies them. So the positive 6.5 V analog voltage,
125connected to the upper Keithley 2200-20-5 power supply in \ref Figure_post_FE_FE_PS has one black tie. The negative power -6.5 V voltage is connected to the
126Keithley 2200-20-5 in the middle and has 2 black ties. Note that this last is connected with red with red and black with black since ite polarity
127is inverted within the filter.The digital 5.2 V is connected to the power suupply inn the middle of the HM7042-3 and has 3 black ties.
128\n The detector positive bias, that can range between 5 V and 30.2 V is the left of the HM7042-3 and has 4 black ties. Finally, the negative detector bias voltage that can
129range btween -5 V and -30.2 V, is the right connection of the HM7042-3 power supply and has 5 black ties. Note that this last is connected with red with red and black with black since ite polarity
130is inverted within the filter.
131
132\attention <b> THIS IS IMPORTANT TO FOLLOW: </b> Before the power supplies must be switced ON or OFF the high voltage to the detector bias (0/30 V)
133must be lowered around 5 V for avoiding possible damages to the front end.
134
135*\anchor Figure_post_FE_FE_PS
136*\image html front-end_power_supplies.jpg "Figure_post_FE_FE_PS 5: Power supply system for front end, post front end and detectors" width=40%
137*\image latex front-end_power_supplies.jpg "Figure_post_FE_FE_PS 5: Power supply system for front end, post front end and detectors" width=40%
142\n The DAQ is the last stage of the front end and is shown in \ref Figure_DAQ_rack_inside. On the left of the picture there is
143the DAQ board
144consisting in an antialisng 6-ples Bessel-Thompson filter and the 24-bits Σ-Δ ADC for 12 channels.
145\n On its side, on the right, laid on the rack floor, there is the ethernet optical transducer whose output feed a second module
146whose output is a standard ethernet connection to the PC. The input to the first optical module comes from the backplane of the DAQ
147board, see \ref Figure_DAQ_rear. The combination of the optical modues allows to implement the copper-fiber optic-copper chain,
148isolating electrically the PC from the DAQ.
149
150*\anchor Figure_DAQ_rack_inside
151*\image html daq_inside.jpg "Figure_DAQ_rack_inside 6: DAQ board inside its rack and its ethernet connection" width=30%
152*\image latex daq_inside.jpg "Figure_DAQ_rack_inside 6: DAQ board inside its rack and its ethernet connection" width=30%
153
154\n On the rear of the DAQ there is the backplane, \ref Figure_DAQ_rear, from where we have seen that digitized data are sent via ethernet link
155and the anlog input from the front end arive.
156
157*\anchor Figure_DAQ_rear
158*\image html daq_rear.jpg "Figure_DAQ_rear 7: DAQ rear connection to the analog input cable from post front end" width=30%
159*\image latex daq_rear.jpg "Figure_DAQ_rear 7: DAQ rear connection to the analog input cable from post front end" width=30%
160
161\n Power supply to the DAQ system is done with 2 different types of power supply. The first supplies the analog section via the
162HM7042-5, \ref Figure_DAQ_PS, with the 2 sources at left and right location with 13 V setting. The digital part of the DAQ is fed with the source in the
163centre, set at 6 V.
164
165\note This layout is temporary. Just in case, consider to connect the banana with the color corrispondence shown in
166\ref Figure_DAQ_PS. This to work needs that the connections on the backplane of the DAQ are not modified. In case
167both side of the cables are removed, please ask at the mail indicated in \ref Introduction.
168
169*\anchor Figure_DAQ_PS
170*\image html daq_power_supply.jpg "Figure_DAQ_PS 8: DAQ power supplies" width=30%
171*\image latex daq_power_supply.jpg "Figure_DAQ_PS 8: DAQ power supplies" width=30%
172
173\n The FPGA on the backplane and the 2 optical modules need to be biasd with the 3 modules shown in \ref Figure_DAQ_FPGA_PS. Actually,
174in \ref Figure_DAQ_FPGA_PS the module shown are only 2, the third, missed in the figure, where located in an other side atthe time of
175the picture.
176
177*\anchor Figure_DAQ_FPGA_PS
178*\image html daq_fpga_power_supply.jpg "Figure_DAQ_FPGA_PS 9: DAQ FPGA power supply" width=30%
179*\image latex daq_fpga_power_supply.jpg "Figure_DAQ_FPGA_PS 9: DAQ FPGA power supply" width=30%
180
181*\section Control_and_acquisition_PC Control and acquisition PC
unimib