N844 & N845 User Manual
Contents
1. 00103 00 844 5 MUTx 07 Technical Information Manual Revision n 7 5 July 2011 MOD N844 N844P N845 8 16 CHANNEL LOW THRESHOLD DISCRIMINATOR CAEN will repair or replace any product within the guarantee period if the Guarantor declares that the product is defective due to workmanship or materials and has not been caused by mishandling negligence on behalf of the User accident or any abnormal conditions or operations CAEN declines all responsibility for damages or injuries caused by an improper use of the Modules due to negligence on behalf of the User It is strongly recommended to read thoroughly the CAEN User s Manual before any kind of operation CAEN reserves the right to change partially or entirely the contents of this Manual at any time and without giving any notice Disposal of the Product The product must never be dumped in the Municipal Waste Please check your local regulations for disposal of electronics products MADE IN ITALY We stress the fact that all the boards are made in Italy because in this globalized world where getting the lowest possible price for products sometimes translates into poor pay and working conditions for the people who make them at least you know that who made your board was reasonably paid and worked in a safe environment this obviously applies only to the boards marked MADE IN ITALY we can not attest to the manufacturing process of third party boards CAEN2. Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 TABLE OF CONTENTS 1 GENERAL DESCRIPTION oisssccsssccessccscscesossocsscenccesoconssdsesteccesosevesteassvsstonsedensevesscnsessedebvecedesceevectescssssnesoceses 4 114 FUNCTIONAL DESCRIPTION ag AN A GS ES EN ag E AS a AN A aas GN EE SE Wa E Sa 4 12 BLOCK DIAGRAM aa E E a D DE NIS EN EE AGE IG NI NGE a aa BA Da Gg a anah 5 2 TECHNICAL SPECIFICATIONS 000000000000 0000000000000000 0000000000000000 000000000000 nane en eneo eee eeen ena 6 Dele PACKAGING 6 2 2 POWER REQUIREMENTS cccccecssssssececccecsesssaececececsenseascecececeeseaaesesececsensaeaeeeeececsessaaeeeeeceeseeeaeseeseseneneaeeee 6 2 3 AND BACK PANEL cccccccccccccccccsesccesesesceuscsescsusesesesusesusesusesuscsuscsusssusesususussausvausususesuaseuessussevessuevens T 2 4 INPUT OUTPUT CONNECTIONS reia rar a ane ena Bwana A A a Aa a 8 2 4 1 INPUT feature Senisi enan a A 8 2 4 2 OUTPUT JOQure S saiecicisevsascicunvanssuaesctiesaesuenentecteawhceiveavenansesnssucvsvuescvsbsenueveshsabetaSies Tg aana ye amp 2 9 OTHER COMPONENTS cccccoccccsscsccececccecocscesesecescoececsccsesececcc
3. 2 bridged LEMO 00 type conneciors Electrical specifications standard NIM signal high impedance 5 ns minimum FWHM 70 MHz maximum input frequency Test Outptut delay 10 ns Mechanical specifications 48 24 32 16 Fan Out of two for OUT and 16 8 single for OUT LEMO 00 connectors Electrical specifications NIM level on 50 Ohm impedance pulse width adjustment from 6 ns to 106 ns I O delay 9 5 ns Mechanical specifications 2 LEMO 00 type connectors Fan Out of two Electrical specifications standard signal 50 impedance 10ns minimum FWHM 50 MHz maximum frequency Mechanical specifications 2 bridged 00 type connectors Electrical specifications Number of pages Page 12 8 CAEN Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 current output 1 mA 20 per hit high impedance 15 ns minimum FWHM 30 MHz maximum frequency 2 5 Other components 2 5 1 Displays The front panel hosts the following LEDs INPUT Type 16 8 red LEDs Function channel selected they light up either when the channels are being programmed or when they are inhibited OR Type 1 green LED Function it lights up if at least one output signal is present 4 DIGIT DISPLAY Type 4 digit red LED display Function it indicates the channels status and programmed parameters values 2 5 2 Front panel sw
4. must be confirmed by placing the Lower Switch on the LCK position otherwise it is ignored The Filename Number of pages Page 11 00103 00 844 5 MUTx 07 n844n845_rev7 12 CAEN Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 3 4 NPO threshold value is set via the front panel Rotary handle see 2 5 3 and shown on the 4 Digit Display 1 leads to a 1mV and 255 to a 255 mV threshold value reversed values for the N844 the step which follows 255 is four appearing on the display the relevant channel is inhibited then again 0 1 2 etc inhibited channels Leds are always lit when the lower switch is in lock LCK position Once all the channels thresholds have been set to the desired value the Lower Switch must be placed on the LCK lower position and the word LOCK appears on the display Setting the output pulse width The output pulse width is adjustable on 8 bit from 6 to 106 ns and the chosen value is applied to a group of 8 channels each The Mod N845 has two groups Ch 0 1 4 5 8 9 12 13 and Ch 2 3 6 7 10 11 14 15 respectively the Mod N844 has only one group The Upper Switch must be placed on the WDT position and the Lower Switch removed from the LCK position then the group is selected pulling up repeatedly the Lower Switch the selected group s Leds light up all together The width s valu
5. S c 560 seseh naa made eea e En en aa Er HEHE HEE EA HE BE e NA TE EE E PEENES PEN Eon ea ae aa Ha aa e agi 6 TABLE 2 2 TECHNICAL SPECIFICATION TABLE cccccccccccscccesecsccoscocscccesecscccscecscecesevscccececscecesesecccssocececesevescoesevevevees 10 NPO Filename Number of pages Page 00103 00 844 5 MUTx 07 n844n845_rev7 12 3 CAEN Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 1 General description 1 1 NPO Functional description The CAEN Model N845 is a 16 CHANNEL LOW THRESHOLD DISCRIMINATOR housed in a single width NIM module The module accepts 16 negative inputs and produces 16 NIM outputs 16 NIM outputs complementary on 48 front panel LEMO 00 connectors NIM outputs are provided with a Fan Out of two a functional block diagram is shown in Fig 1 1 A 8 Channel version the CAEN Model N844 sharing the same functional features with the 16 Channel Model N845 is also available The timing stage of the discriminator produces an output pulse whose width is adjustable in a range from 6 to 106 ns The discriminator thresholds are individually settable in a range from 1 mV to 255 mV 1 mV step via an 8 bit DAC A 8 Channel positive input version Model N844 with the thresholds settable in the 1 mV to 255 mV range is also available N844 boards can be converted into N844P and N844P into N844 as well by CAEN P
6. e is set via the Rotary Handle and shown on the display 0 leads to a 6 ns and 255 to a 106 ns width with a non linear relation for intermediate values the step which follows 255 is again 0 then 1 2 etc Once the Pulse Widths have been programmed the Lower Switch must be placed on the LCK position and the word LOCK appears on the display Filename Number of pages Page 12 00103 00 844 5 MUTx 07 n844n845_rev7 12
7. ersonnel module must be returned to CAEN the Ordering Code of the customization is WN844POLEXCH The back panel houses VETO and TEST inputs the logical OR output the relevant OR LED lights up if at least one channel is over threshold and the Current Sum gt output which generates a current proportional to the input multiplicity to the number of channels over threshold at a rate of 1 0 mA per hit 50 mV per hit into a 50 Ohm load 20 Table 1 1 Available items Code Item Description WN844POLEXCH N844 Polarity Exchange Polarity Exchange WN844PXAAAAA N844P 8 Ch Low Threshold Discriminator 500hm Positive Inputs WN844XAAAAAA N844 8 Ch Low Threshold Discriminator 50 Ohm Negative Inputs WN845XAAAAAA N845 16 Ch Low Threshold Discriminator 50 Ohm Negative Inputs Filename Number of pages Page 00103 00 844 5 MUTx 07 n844n845_rev7 12 4 CAEN ls for Discovery Document type User s Manual MUT Title 1 2 Block diagram NPO 00103 00 844 5 MUTx 07 n844n845_rev7 Number of pages 12 Revision date Revision Mod N844 N845 8 16 Channel Low Thresho
8. esocscosececesccecessosesecevoceserscoseseresccecerssosesenevosesons 9 2 5 1 Displays sasa aapa ngae a apaa a aa aeng dusty maea aa sa naa apaa 9 25 2 Fron PANEL aa ae a aaa eng a papa apaa angine 9 293 Rotary handle 9 2 6 TECHNICAL SPECIFICATION TABLE err err 10 3 OPERATING MODES sssisscscscessciesssssccsscuseescsssbececssusdecsastecescosvedsesdescsdevossscessessssouses svsdssssnsessessadsesseseisoessece 11 31 sPOWER ON STATUS visas sebsuesvedecesdsnesesoeseiecoevsdeb suns ves a a a D a aaa a ae ga a Ng Ta 11 32 BACK SIGNALS anaa SANES aga 11 3 3 SETTING THE THRESHOLD AND DISABLING THE CHANNELS 11 3 4 SETTING THE OUTPUT PULSE 12 LIST OF FIGURES FIG 1 1 MOD N845 BLOCK DIAGRAM 16 CHANNEL 5 2 1 MOD N845 N844 FRONT PANEL AND BACK PANEL ccccccccccccccccccccccsccesecescsesesesceesceesceesceeeceescessceseeesseeeeeees T LIST OF TABLES TABLE 1 1 AVAILABLE ITEMS ccccccccccecscecscecececsceceeecscscececscucseuceeucucucueueucucueucuaucuauausucuauaucucuauauauauaucuaueuauauaueuenenees 4 TABLE 2 1 POWER REQUIREMENT
9. itches UPPER SWITCH Function it allows to select the parameter which must be programmed LOWER SWITCH Function it allows to select the channel block which must be programmed SEL mode and to freeze the programmed values LCK mode 2 5 3 Rotary handle Function it allows to set the value of the parameter which is being programmed NPO Filename Number of pages Page 00103 00 844 5 MUTx 07 n844n845_rev7 12 9 Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 2 6 Technical specification table Table 2 2 Technical specification table Features referred to Mod N845 N844 N844 P features specified between Packaging 1U wide NIM unit Input channels 16 8 inputs negative N844 negative N844 P positive polarity 50 Q impedance DC coupling N844 N845 400 mV N844 P 400 mV N844 N845 3 mV N844 3 mV 16 ns 8 ns output pulse width ae 32 16 NIM bridged 16 8 NIM single 50 mawan Output rise fall time OUT 1 2 ns OUT 2 5 ns Interchannel insulation 45 dB for 2 5 ns rise time input signals NIM signals high impedance Control inputs VETO allows vetoing of all channels simultaneously TEST triggers all the enabled channels at once OR standard NIM signal 50 2 impedance logic OR of outputs Control outputs current proportional to input multi
10. ld Discriminator 05 07 2011 7 _ ENE DACs INHIBIT 1 jl 1 L 8 bit 8 bit 8 bit rani DAC DAC DAC DAC DAC N WTH WTH DAG 0 7 8 15 ch 0 ch 1 ch14 ch 15 25572 THRESHOLDS 6 WIDTH C P U ao DEAD TIME INPUTS lt 0 15 gt IK 4 Yy discr oliye jian discr discr ch 0 1 ch 14 ch 15 N TEST 4 OR LED VETO l 4 DISPLAY A 7 OUTPUTS lt 0 15 gt OR 27 OUT 14 Fig 1 1 Mod 845 Block Diagram 16 Channel Filename Page 5 Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 2 Technical Specifications 2 1 Packaging The Model N844 N845 is housed in a 1U wide NIM unit 2 2 Power requirements The power requirements of the Mod N844 N845 are as follows Table 2 1 Power requirements Power Supply N844 N844P N845 400 mA 800 mA 1 85 NPO Filename Number of pages 00103 00 844 5 MUTx 07 n844n845_rev7 12 Page 6 CAEN Document type User s Manual MUT 2 3 Front and back panel Title Mod N844 N845 8 16 Channel Low Threshold Discriminator 000803 08090505 3 S WE OIO oy ee 0 0 OO NPO 00103 00 844 5 MUTx 07 Fig 2 1 Mod N845 N844 fr
11. ont panel and back panel Filename n844n845_rev7 Revision date Revision lt Number of pages Page 12 7 CAEN Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 2 4 Input Output connections The location of the Mod N844 N845 connectors is shown in Fig 2 1 Their function and electromechanical specifications are listed in the following subsections and refer to the N845 the Mod 844 features specified between 2 4 1 INPUT features INPUT CHANNELS VETO INPUT TEST INPUT 2 4 2 OUTPUT features OUTPUT CHANNELS OR OUTPUT OUTPUT NPO 00103 00 844 5 MUTx 07 Filename n844n845_rev7 Mechanical specifications 16 8 LEMO 00 type connectors Electrical specifications Neg polarity pos on N844 P 50 Ohm impedance DC coupling maximum ratings N844 N845 0 4 V N844 P 0 4 V max input frequency 60 MHz Min input 3 mV N844 and N845 3 mV N844 P Mechanical specifications 2 bridged LEMO 00 type conneciors Electrical specifications standard NIM signal high impedance 15 ns minimum FWHM leading edge of the VETO must precede of at least 12 ns the leading edge of the input and overlap completely the input signal acts on all signals Mechanical specifications
12. plicity 1 mA 20 hit high impedance INPUTS 16 8 red LEDs they light up when the channel is being programmed or when it is inhibited Displays 4 DIGIT DISPLAY it indicates the channels status and programmed parameters values OR green LED it lights up if at least one output signal is present NPO Filename Number of pages Page 00103 00 844 5 MUTx 07 n844n845_rev7 12 10 CAEN Document type Title Revision date Revision User s Manual MUT Mod N844 N845 8 16 Channel Low Threshold Discriminator 05 07 2011 7 3 Operating Modes 3 1 3 2 3 3 NPO Power ON Status At Power ON the values of all the module s parameters are those programmed before the last turning off If one parameter s value is meaningless the unit sets it at half of its range Back panel signals Some operations can be performed via two external NIM signals e TEST an input signal sent through this connector triggers all the enabled channels at once This feature allows a complete test of the module without removing any input cable as well as it allows generation of a pattern of pulses suitable to test any following electronics e VETO an input signal sent through this connector allows vetoing of all channels simultaneously A veto pulse of width T will veto the input during this time T Its leading edge must precede the output leading edge by at least 12 ns and overlap completely the input signal VETO does not affec
13. t the TEST signal Each one of these high impedance inputs is provided via two bridged connectors placed on the board s back panel for daisy chaining Note that since these are high impedance inputs the chain has thus to be terminated on 50 on the last module the same is needed whenever one module only is used whose inputs have thus to be properly matched Moreover the back panel houses a Current Sum gt output on two bridged connectors which generates a current proportional to the input signal multiplicity i e to the number of channels over threshold at a rate of 1 0 mA per hit 50 mV per hit into a 50 load 20 An OR output with a Fan Out of two provides the logical OR of the output channels Setting the threshold and disabling the channels For each channel of the N844 N845 the discriminator threshold is set up via an 8 bit DAC The threshold values can be programmed in a range from 1 mV to 255 mV with 1 mV steps N844P 1 mV to 255 mV with 1 mV steps In order to set the threshold the Upper Switch see 2 5 2 must be placed on the THR position and the Lower Switch removed from the LCK position then the channel that must be programmed is selected pulling up repeatedly the Lower Switch the selected channel s Led lights up Note that after the last channel by pulling up the lower switch the Leds ligth up all together and at this point the threshold setting is performed over all the channels this value
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