D0 TRIGGER FRAMEWORK ---------------------- D0 NOTE 328 FINAL DRAFT ---------------------- 24-FEB-1986 Maris Abolins Daniel Edmunds James Linnemann Michigan State University CONTENTS ------------ 1. Testing of the Trigger System 2. First Level Trigger Data Block 3. Standards for Adding Information to the First Level Trigger Data Block 4. Specific Trigger Prescalers 5. Specific Trigger Scalers 6. Beam Crossing Scalers 7. Synchronization and Interface with the Data Acquisition System 8. External Information for Input to the AND-OR Network 9. General Purpose Timing Signals 10. Automatically Disabled Specific Triggers 11. Specific Triggers Disabled by the Second Level Trigger Supervisor Computer 12. Transmission of the First Level Trigger Data Block to a Second Level Trigger Node 13. Communications between the First Level Trigger Control Computer, Second Level Trigger Supervisor Computer, and the Host Computer 14. Communications between the Trigger Framework, the Second Level Trigger Supervisor Computer, and the Second Level Trigger Processor Nodes 15. Limitations 16. Figure Captions D0 TRIGGER FRAMEWORK ---------------------- 1. TESTING OF THE TRIGGER SYSTEM Testing of the trigger system should be considered in two parts: testing of component triggers e.g. the Muon Trigger or the Calorimeter Trigger, and testing of the Trigger Framework. Clearly, a different mode of testing and a higher degree of reliability are required for the Trigger Framework than for any of the component triggers. If the former goes down for any reason, the whole experiment stops. To overcome this unacceptable situation, the Trigger Framework has been designed with 100% backup so that any conceivable problem can be repaired without undue down time. The Trigger Framework is tested in two ways. In the first method the Trigger Control Computer selects random events and reads the state of all inputs to the Trigger Framework. The Trigger Control Computer uses this information to calculate the expected output of the Trigger Framework. This information is then compared to the outputs of the Trigger Framework as read by the Trigger Control Computer. This method of testing checks for consistencies and does not interfere with the normal operation of the Trigger Framework. In the second method of testing, the Trigger Framework must be taken offline and all normal trigger operations are suspended. Once offline the Trigger Control Computer can present to the Trigger Framework a set of inputs and then reads the resulting outputs. These outputs are compared to the expected results. This method of detailed testing should quickly locate the source of any malfunction to the board level. To aid in testing of the Trigger Framework, all circuits have been designed so that any register that can be written can also be read. There are no write only registers. During normal running the Trigger Control Computer will also monitor certain functions of the Trigger Framework. This would include monitoring the Beam Crossing Scalers both to verify their proper operation and to look for Specific Triggers with excessive dead time. 2. FIRST LEVEL TRIGGER DATA BLOCK The First Level Trigger Data Block is a fixed format block of data that is transferred from the Trigger Framework to a Second Level Trigger Computer any time the First Level Trigger fires. The First Level Trigger Data Block contains information about the beam crossing that generated the First Level Trigger and about the preceding beam crossing. The First Level Trigger Data Block may contain information from sources other than the Trigger Framework and the Calorimeter Trigger (e.g. the Muon Trigger or the TRD Trigger). All data structures in the First Level Trigger Data Block must begin at fixed addresses but they may be of variable length. STRUCTURE of the FIRST LEVEL TRIGGER DATA BLOCK ------------------------------------------------- BEGINNING LENGTH IN ADDRESS BYTES CONTENTS ---------- ----------- ---------- DATA FROM CURRENT BEAM CROSSING 0 32 Status of all bits in the AND-OR NETWORK 32 4 Status of all 32 Specific Triggers 36 128 Specific Trigger Scalers 4 bytes each 164 165 Beam Crossing Scalers 5 bytes each 329 1 Et EM 330 1 Et HAD 331 1 Et Total 332 1 Missing Pt 333 1 Direction of Missing Pt 334 40 Jet List 4 bytes per jet x 5 jets each type 374 4 TRD hits 378 1600 EM Trigger Tower ADC's 1978 1600 HAD Trigger Tower ADC's 3578 518 MAX Data added to the First Level Trigger Data Block from other sources DATA FROM PREVIOUS BEAM CROSSING 4096 32 Status of all bits in the AND-OR NETWORK 4128 4 Status of all 32 Specific Triggers 4132 128 Specific Trigger Scalers 4 bytes each 4260 165 Beam Crossing Scalers 5 bytes each 4425 1 Et EM 4426 1 Et HAD 4427 1 Et Total 4428 1 Missing Pt 4429 1 Direction of Missing Pt 4430 40 Jet List 4 bytes per jet x 5 jets each type 4470 4 TRD hits 4474 1600 EM Trigger Tower ADC's 6074 1600 HAD Trigger Tower ADC's 7674 518 MAX Data added to the First Level Trigger Data Block from other sources 3. STANDARD FOR ADDING INFORMATION TO THE FIRST LEVEL TRIGGER DATA BLOCK Information may be sent to the Trigger Framework for inclusion in the First Level Trigger Data Block. This information should be sent one byte at a time with an accompanying Strobe Signal. The information will be latched into the Trigger Framework on the Falling Edge (Trailing Edge) of the Strobe Signal. The maximum transfer rate is one transfer every 100 nsec. All data must be transferred by 100 microseconds after the First Level Trigger. The Strobe Signal should be active for between 40 nsec and 60 nsec. The data lines should be stable for 30 nsec minimum before the Falling Edge of the Strobe Signal and should hold for 10 nsec minimum after the Falling Edge of the Strobe Signal. All signals are Positive True logic. All levels are differential ECL. This information is transferred on a 10 pair twisted-flat cable, the FIRST LEVEL TRIGGER DATA BLOCK EXTERNAL INPUT CABLE . At the Receiving End the cable is terminated with a 110 Ohm resistor across each differential pair of lines. The Sending End must provide the pull down resistors to Vtt. The Twisted-Flat cable is Spectra-Strip part number 843-132-2801-20. If requested the Trigger Framework will provide one FIRST LEVEL TRIGGER DATA BLOCK EXTERNAL INPUT CABLE to each of the 7 major Detector Systems: Vertex, TRD, Central Drift, Forward Drift, Muon, Central Calorimeter, End Cap + Plug Calorimeter. FIRST LEVEL TRIGGER BLOCK EXTERNAL INPUT CABLE ------------------------------------------------ PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ---------- 1 BROWN DATA 0 NON-INVERTED LSB ND0 2 TAN DATA 0 INVERTED LSB ID0 3 RED DATA 1 NON-INVERTED ND1 4 TAN DATA 1 INVERTED ID1 5 ORANGE DATA 2 NON-INVERTED ND2 6 TAN DATA 2 INVERTED ID2 7 YELLOW DATA 3 NON-INVERTED ND3 8 TAN DATA 3 INVERTED ID3 9 GREEN DATA 4 NON-INVERTED ND4 10 TAN DATA 4 INVERTED ID4 11 BLUE DATA 5 NON-INVERTED ND5 12 TAN DATA 5 INVERTED ID5 13 VIOLET DATA 6 NON-INVERTED ND6 14 TAN DATA 6 INVERTED ID6 15 GREY DATA 7 NON-INVERTED MSB ND7 16 TAN DATA 7 INVERTED MSB ID7 17 WHITE STROBE NON-INVERTED NST 18 TAN STROBE INVERTED IST 19 BLACK GROUND AT SENDING END OPEN AT RECEIVING END 20 TAN GROUND AT SENDING END OPEN AT RECEIVING END 4. SPECIFIC TRIGGER PRESCALERS Each Specific Trigger has associated with it a prescaler which can be used to reduce the trigger rate due to that Specific Trigger. Each prescaler is 24 bits long so that the rate of any Specific Trigger can be reduced to 1 Hz or less. The prescaler is located at the output of the AND gate in the Specific Trigger AND-OR Network ahead of all subsequent logic. 5. SPECIFIC TRIGGER SCALERS Each Specific Trigger has associated with it a scaler which can be used to determine the rate of that Specific Trigger. These scalers are 24 bits long. Assuming any reasonable rate for the Specific Triggers, then a 24 bit number allows every firing of a Specific Trigger to have a unique Specific Trigger Event Number over a period of one day which will be the time between fills of the accelerator. 6. BEAM CROSSING SCALERS There are 33 Beam Crossing Scalers in the Trigger Framework. One of these scalers is enabled to increment at every beam crossing and counts the total number of beam crossings to which the detector is exposed. The 32 other Beam Crossing Scaler are arranged so that one of them is associated with each Specific Trigger. A scaler in this group is only enabled to increment at beam crossings during which the Specific Trigger with which it is associated has not been disabled. A Specific Trigger can be disabled because any of the following reasons: it is waiting for the acquisition system to finish a cycle (a BUSY SIGNAL), waiting for level 1.5 trigger information to arrive, because it has been programmed to be an Automatically Disabled Specific Trigger, because it has been disabled by the Second Level Trigger Supervisor (ALL NODES IN QUEUE ARE BUSY) or because it has been disabled by the First Level Trigger Control Computer. These 33 Beam Crossing Scalers can be used to determine the integral luminosity to which the detector and each Specific Trigger have been exposed and also to calculate the dead time of each Specific Trigger. Each of these scalers is 40 bits long so that each beam crossing during the time between fills of the accelerator can have a unique Beam Crossing Number. 7. SYNCHRONIZATION AND INTERFACE WITH THE DATA ACQUISITION SYSTEM In order to coordinate the readout of events the Trigger Framework must communicate control signals with the Data Acquisition System (the Front-End Crates and Digitization Crates) and the Second Level Trigger Supervisor Computer. Anytime the First Level Trigger fires it must inform the Second Level Trigger Supervisor and the 8 Data Cable Sequencers about which Specific Triggers have been satisfied. This is done over two 17 pair cables called the SPECIFIC TRIGGERS FIRED CABLE NUMBER 1 and the SPECIFIC TRIGGERS FIRED CABLE NUMBER 2. These two cables provide a separate line for each of the Specific Triggers and a strobe signal. The occurrence of the strobe signal indicates that at least one of the First Level Specific Triggers has fired. This strobe signal, called First Level Trigger Strobe, can be used to generate an interrupt in the Second Level Supervisor Computer. This strobe signal is between 900 nsec and 1100 nsec long. The First Level Trigger Strobe will be sent from the Trigger Framework 3.000 microsecond + or - 10 nsec after a beam crossing that results in a trigger. The falling (trailing) edge of the First Level Trigger Strobe can be used to clock a latch at the Receiving End of the cables to hold the Specific Trigger pattern. Data on these two cables will remain stable until the next First Level Trigger Strobe. All signals on these two cables are Positive True logic. All levels are differential ECL. At the Receiving End the cable must be terminated with a 110 Ohm resistor across each differential pair of lines. The sending end will provide the pull down resistors to Vtt. The Twisted-Flat cables are Spectra-Strip part number 843-132-2801-34. SPECIFIC TRIGGERS FIRED CABLE NUMBER 1 ---------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ----------- 1 BROWN SPECIFIC TRIGGER 1 NON-INVERTED NSP1 2 TAN SPECIFIC TRIGGER 1 INVERTED ISP1 3 RED SPECIFIC TRIGGER 2 NON-INVERTED NSP2 4 TAN SPECIFIC TRIGGER 2 INVERTED ISP2 5 ORANGE SPECIFIC TRIGGER 3 NON-INVERTED NSP3 6 TAN SPECIFIC TRIGGER 3 INVERTED ISP3 7 YELLOW SPECIFIC TRIGGER 4 NON-INVERTED NSP4 8 TAN SPECIFIC TRIGGER 4 INVERTED ISP4 9 GREEN SPECIFIC TRIGGER 5 NON-INVERTED NSP5 10 TAN SPECIFIC TRIGGER 5 INVERTED ISP5 11 BLUE SPECIFIC TRIGGER 6 NON-INVERTED NSP6 12 TAN SPECIFIC TRIGGER 6 INVERTED ISP6 13 VIOLET SPECIFIC TRIGGER 7 NON-INVERTED NSP7 14 TAN SPECIFIC TRIGGER 7 INVERTED ISP7 15 GREY SPECIFIC TRIGGER 8 NON-INVERTED NSP8 16 TAN SPECIFIC TRIGGER 8 INVERTED ISP8 17 WHITE SPECIFIC TRIGGER 9 NON-INVERTED NSP9 18 TAN SPECIFIC TRIGGER 9 INVERTED ISP9 19 BLACK SPECIFIC TRIGGER 10 NON-INVERTED NSP10 20 TAN SPECIFIC TRIGGER 10 INVERTED ISP10 21 BROWN SPECIFIC TRIGGER 11 NON-INVERTED NSP11 22 TAN SPECIFIC TRIGGER 11 INVERTED ISP11 23 RED SPECIFIC TRIGGER 12 NON-INVERTED NSP12 24 TAN SPECIFIC TRIGGER 12 INVERTED ISP12 25 ORANGE SPECIFIC TRIGGER 13 NON-INVERTED NSP13 26 TAN SPECIFIC TRIGGER 13 INVERTED ISP13 27 YELLOW SPECIFIC TRIGGER 14 NON-INVERTED NSP14 28 TAN SPECIFIC TRIGGER 14 INVERTED ISP14 29 GREEN SPECIFIC TRIGGER 15 NON-INVERTED NSP15 30 TAN SPECIFIC TRIGGER 15 INVERTED ISP15 31 BLUE SPECIFIC TRIGGER 16 NON-INVERTED NSP16 32 TAN SPECIFIC TRIGGER 16 INVERTED ISP16 33 VIOLET FIRST LEVEL TRIGGER STROBE NON-INVERTED NFLTS 34 TAN FIRST LEVEL TRIGGER STROBE INVERTED IFLTS SPECIFIC TRIGGERS FIRED CABLE NUMBER 2 ---------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ----------- 1 BROWN SPECIFIC TRIGGER 17 NON-INVERTED NSP17 2 TAN SPECIFIC TRIGGER 17 INVERTED ISP17 3 RED SPECIFIC TRIGGER 18 NON-INVERTED NSP18 4 TAN SPECIFIC TRIGGER 18 INVERTED ISP18 5 ORANGE SPECIFIC TRIGGER 19 NON-INVERTED NSP19 6 TAN SPECIFIC TRIGGER 19 INVERTED ISP19 7 YELLOW SPECIFIC TRIGGER 20 NON-INVERTED NSP20 8 TAN SPECIFIC TRIGGER 20 INVERTED ISP20 9 GREEN SPECIFIC TRIGGER 21 NON-INVERTED NSP21 10 TAN SPECIFIC TRIGGER 21 INVERTED ISP21 11 BLUE SPECIFIC TRIGGER 22 NON-INVERTED NSP22 12 TAN SPECIFIC TRIGGER 22 INVERTED ISP22 13 VIOLET SPECIFIC TRIGGER 23 NON-INVERTED NSP23 14 TAN SPECIFIC TRIGGER 23 INVERTED ISP23 15 GREY SPECIFIC TRIGGER 24 NON-INVERTED NSP24 16 TAN SPECIFIC TRIGGER 24 INVERTED ISP24 17 WHITE SPECIFIC TRIGGER 25 NON-INVERTED NSP25 18 TAN SPECIFIC TRIGGER 25 INVERTED ISP25 19 BLACK SPECIFIC TRIGGER 26 NON-INVERTED NSP26 20 TAN SPECIFIC TRIGGER 26 INVERTED ISP26 21 BROWN SPECIFIC TRIGGER 27 NON-INVERTED NSP27 22 TAN SPECIFIC TRIGGER 27 INVERTED ISP27 23 RED SPECIFIC TRIGGER 28 NON-INVERTED NSP28 24 TAN SPECIFIC TRIGGER 28 INVERTED ISP28 25 ORANGE SPECIFIC TRIGGER 29 NON-INVERTED NSP29 26 TAN SPECIFIC TRIGGER 29 INVERTED ISP29 27 YELLOW SPECIFIC TRIGGER 30 NON-INVERTED NSP30 28 TAN SPECIFIC TRIGGER 30 INVERTED ISP30 29 GREEN SPECIFIC TRIGGER 31 NON-INVERTED NSP31 30 TAN SPECIFIC TRIGGER 31 INVERTED ISP31 31 BLUE SPECIFIC TRIGGER 32 NON-INVERTED NSP32 32 TAN SPECIFIC TRIGGER 32 INVERTED ISP32 33 VIOLET FIRST LEVEL TRIGGER STROBE NON-INVERTED NFLTS 34 TAN FIRST LEVEL TRIGGER STROBE INVERTED IFLTS For purposes of synchronizing the operations of the Trigger Framework and the Data Acquisition System, the Data Acquisition System is divided into 32 sections. The signals that control the synchronization of these two systems are: Start Digitization Command, Front-End Crate Busy Signal, Clear Most Recent Trigger Signal, and Beam Crossing Number. These signals are carried in a separate cable to each one of the 32 Sections of the Data Acquisition System. These 32 cables are called the TRIGGER-ACQUISITION SYNCHRONIZATION CABLES. Start Digitization Command When the Trigger Framework sends out a First Level Trigger it will also send out information indicating which Sections of the Data Acquisition System should start a digitization cycle in response to the Specific Trigger(s) that has(have) fired. A separate Start Digitization Command is generated by the Trigger Framework for each Section of the Data Acquisition System. When received by a Section of the Data Acquisition System the Start Digitization Command is used to initiate the readout of that Section. The mapping of Specific Triggers fired versus which Sections of the Data Acquisition System should begin a digitization cycle is controlled by the programmable Specific Triggers Versus Sections Digitized Lookup Memory. This lookup memory maps the 32 Specific Triggers onto the 32 Start Digitization Commands. The Start Digitization Commands will be sent from the Trigger Framework 3.050 microseconds + or - 10 nsec after a beam crossing that results in a First Level Trigger. The Start Digitization Command will be a pulse signal that has a length of 900 nanoseconds to 1100 nanoseconds. For beam crossings that do result in a First Level Trigger, Start Digitization Commands will be sent only to those Sections of the Data Acquisition System that are selected by the Specific Triggers Versus Sections Digitized Lookup Memory. For beam crossings that do not result in a First Level Trigger, all Start Digitization Commands will remain inactive. Front-End Crate Busy Signal When both halves of the analog double buffer in a section of Front-End Crates are in use then the Trigger Framework should not generate another Specific Trigger that will involve the readout of that Section of the Data Acquisition System. Front-End Crates indicate to the Trigger Framework that their analog double buffer is full by sending a Front-End Crate Busy Signal to the Trigger Framework. The mapping of Front-End Crate Busy Signals versus which Specific Triggers must be disabled is controlled by the programmable Front-End Crate Busy Signal Versus Specific Triggers Disabled Lookup Memory. A Front-End Crate Busy Signal must have arrived at the Trigger Framework and be stable by 2.9 microseconds after a beam crossing that must be prevented from generating a Specific Trigger involving the readout of that Section of the Data Acquisition System. The Trigger Framework supports a total of 32 Front-End Crate Busy Signals. The Data Acquisition System is divided into Sections in such a way that the sections serviced by the Start Readout Command signals are the same as the sections serviced by the Front-End Crate Busy signals. Clear Most Recent Trigger Signal After sending out a First Level Trigger the Trigger Framework may wait for more information about the beam crossing that caused the trigger and then make a Level 1.5 decision. If the result of the Level 1.5 decision is to go ahead and keep the event then the Trigger Framework does nothing (except enable itself to send out a First Level Trigger the next time it finds an interesting beam crossing). If the result of the Level 1.5 decision is to stop the Data Acquisition cycle that has just started then the Trigger Framework sends out a Clear Most Recent Trigger signal. The Clear Most Recent Trigger signal is sent only to those Sections of the Data Acquisition System that had been sent Start Digitization Commands. The effect in the Data Acquisition System of receiving a Clear Most Recent Trigger signal is to stop and undo what ever action has been taken in response to the most recent Start Digitization Command. Not all First Level Specific Triggers will be associated with a subsequent Level 1.5 decision. For those Level One Specific Triggers that are programmed to wait and make a Level 1.5 Decision the time interval between the Level One Specific Trigger and the subsequent Level 1.5 decision is expected to be about 20 microseconds. During this time interval there will not be any additional Level One Triggers. When a Clear Most Recent Trigger signal is sent from the Trigger Framework it will be a pulse between 900 nanoseconds and 1100 nanoseconds wide. Beam Crossing Number The Beam Crossing Number is sent from the Trigger Framework to the Data Acquisition System to help separate information from different beam crossings. The Trigger Framework will supply a 16 bit Beam Crossing Number. This 16 bit number will be unique for a period of about 1/4 of a second. The Beam Crossing Number will update between the time of the beam crossing and 200 nseconds after the beam crossing. The Beam Crossing Number is guaranteed to be stable at all times except between the time of the beam crossing and 200 nseconds after the beam crossing. If the user wishes the Rising Edge (Leading Edge) of the Start Digitization Command may be used to clock the Beam Crossing Number into a latch at the receiving end of the cable. TRIGGER-ACQUISITION SYNCHRONIZATION CABLES All signals in the 32 TRIGGER-ACQUISITION SYNCHRONIZATION CABLES are Positive True logic. All levels are differential ECL. The information is transferred on a 20 pair twisted-flat cable. At the Receiving End a signal must be terminated with a 110 Ohm resistor across each differential pair of lines. The Sending End of a signal will provide the pull down resistors to Vtt. The Twisted-Flat cable is Spectra-Strip part number 843-132-2801-40. TRIGGER-ACQUISITION SYNCHRONIZATION CABLE 1 OF 32 CABLES ------------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ----- ----------- -------- ---------- 1 BROWN BEAM CROSSING NUMBER BIT 0 NON-INVERTED NBCN0 2 TAN BEAM CROSSING NUMBER BIT 0 INVERTED IBCN0 3 RED BEAM CROSSING NUMBER BIT 1 NON-INVERTED NBCN1 4 TAN BEAM CROSSING NUMBER BIT 1 INVERTED IBCN1 5 ORANGE BEAM CROSSING NUMBER BIT 2 NON-INVERTED NBCN2 6 TAN BEAM CROSSING NUMBER BIT 2 INVERTED IBCN2 7 YELLOW BEAM CROSSING NUMBER BIT 3 NON-INVERTED NBCN3 8 TAN BEAM CROSSING NUMBER BIT 3 INVERTED IBCN3 9 GREEN BEAM CROSSING NUMBER BIT 4 NON-INVERTED NBCN4 10 TAN BEAM CROSSING NUMBER BIT 4 INVERTED IBCN4 11 BLUE BEAM CROSSING NUMBER BIT 5 NON-INVERTED NBCN5 12 TAN BEAM CROSSING NUMBER BIT 5 INVERTED IBCN5 13 VIOLET BEAM CROSSING NUMBER BIT 6 NON-INVERTED NBCN6 14 TAN BEAM CROSSING NUMBER BIT 6 INVERTED IBCN6 15 GREY BEAM CROSSING NUMBER BIT 7 NON-INVERTED NBCN7 16 TAN BEAM CROSSING NUMBER BIT 7 INVERTED IBCN7 17 WHITE BEAM CROSSING NUMBER BIT 8 NON-INVERTED NBCN8 18 TAN BEAM CROSSING NUMBER BIT 8 INVERTED IBCN8 19 BLACK BEAM CROSSING NUMBER BIT 9 NON-INVERTED NBCN9 20 TAN BEAM CROSSING NUMBER BIT 9 INVERTED IBCN9 21 BROWN BEAM CROSSING NUMBER BIT 10 NON-INVERTED NBCN10 22 TAN BEAM CROSSING NUMBER BIT 10 INVERTED IBCN10 23 RED BEAM CROSSING NUMBER BIT 11 NON-INVERTED NBCN11 24 TAN BEAM CROSSING NUMBER BIT 11 INVERTED IBCN11 25 ORANGE BEAM CROSSING NUMBER BIT 12 NON-INVERTED NBCN12 26 TAN BEAM CROSSING NUMBER BIT 12 INVERTED IBCN12 27 YELLOW BEAM CROSSING NUMBER BIT 13 NON-INVERTED NBCN13 28 TAN BEAM CROSSING NUMBER BIT 13 INVERTED IBCN13 29 GREEN BEAM CROSSING NUMBER BIT 14 NON-INVERTED NBCN14 30 TAN BEAM CROSSING NUMBER BIT 14 INVERTED IBCN14 31 BLUE BEAM CROSSING NUMBER BIT 15 NON-INVERTED NBCN15 32 TAN BEAM CROSSING NUMBER BIT 15 INVERTED IBCN15 33 VIOLET START DIGITIZATION COMMAND NON-INVERTED NSDGC 34 TAN START DIGITIZATION COMMAND INVERTED ISDGC 35 GREY FRONT-END CRATE BUSY NON-INVERTED NFECB 36 TAN FRONT-END CRATE BUSY INVERTED IFECB 37 WHITE CLEAR MOST RECENT TRIGGER NON-INVERTED NCLRT 38 TAN CLEAR MOST RECENT TRIGGER INVERTED ICLRT 39 BLACK OPEN AT FRAMEWORK END GROUNDED AT ACQUISITION END 40 TAN OPEN AT FRAMEWORK END GROUNDED AT ACQUISITION END 8. EXTERNAL INFORMATION FOR INPUT TO THE AND-OR NETWORK Certain external trigger systems (e.g. the Muon Trigger and the Level Zero Trigger) will need to send information to the AND-OR Network for inclusion in the programming of Specific Triggers. The inputs for external signals to the AND-OR Network are available in blocks of 8 bits. Any information being sent to the AND-OR Network through these inputs must arrive at the receiving end of the cable (the Trigger Framework) and be stable no later than 2.9 microsec after beam crossing. At 2.9 microseconds after beam crossing this information will be clocked into the Intermediate Latch and then sent to the AND-OR Network. All signals are Positive True logic. All levels are differential ECL. This information is transferred on a 10 pair twisted-flat cable, the EXTERNAL INPUT TO THE AND-OR NETWORK CABLE. At the Receiving End this cable is terminated with a 110 Ohm resistor across each differential pair of lines. The Sending End must provide the pull down resistors to Vtt. The Twisted-Flat cable is Spectra-Strip part number 843-132-2801-20. EXTERNAL INPUT TO AND-OR NETWORK CABLE ---------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ----------- 1 BROWN EXTERNAL INPUT 0 NON-INVERTED NEI0 2 TAN EXTERNAL INPUT 0 INVERTED IEI0 3 RED EXTERNAL INPUT 1 NON-INVERTED NEI1 4 TAN EXTERNAL INPUT 1 INVERTED IEI1 5 ORANGE EXTERNAL INPUT 2 NON-INVERTED NEI2 6 TAN EXTERNAL INPUT 2 INVERTED IEI2 7 YELLOW EXTERNAL INPUT 3 NON-INVERTED NEI3 8 TAN EXTERNAL INPUT 3 INVERTED IEI3 9 GREEN EXTERNAL INPUT 4 NON-INVERTED NEI4 10 TAN EXTERNAL INPUT 4 INVERTED IEI4 11 BLUE EXTERNAL INPUT 5 NON-INVERTED NEI5 12 TAN EXTERNAL INPUT 5 INVERTED IEI5 13 VIOLET EXTERNAL INPUT 6 NON-INVERTED NEI6 14 TAN EXTERNAL INPUT 6 INVERTED IEI6 15 GREY EXTERNAL INPUT 7 NON-INVERTED NEI7 16 TAN EXTERNAL INPUT 7 INVERTED IEI7 17 WHITE GROUND AT SENDING END OPEN AT RECEIVING END 18 TAN GROUND AT SENDING END OPEN AT RECEIVING END 19 BLACK GROUND AT SENDING END OPEN AT RECEIVING END 20 TAN GROUND AT SENDING END OPEN AT RECEIVING END 9. GENERAL PURPOSE TIMING SIGNALS The Trigger framework will provide a total of 32 general purpose Timing Signals to the Data Acquisition and Detector Systems. These signals are generated in the Trigger framework and are programmable in steps of 37.7 nsec. As they are sent from the Trigger Framework these signals have an accuracy of + or - 10nsec. All of these Timing Signals are running all of the time (whether or not there is beam in the accelerator and whether or not the Trigger Framework has sent out a First Level Trigger). For testing purposes the timing signals can individually be gated on and off or set to either a low or high level by the First Level Trigger Control Computer. These timing signals are carried on the GENERAL PURPOSE TIMING SIGNAL CABLE. This cable has 17 pairs of lines and carries 16 of the 32 Timing Signals. There is one cable for each of the 7 major Detector Systems: Vertex, TRD, Central Drift, Forward Drift, Muon, Central Calorimeter, End Cap + Plug Calorimeter. Each of the Detector Systems must decide which 16 of the 32 Timing Signals that it needs to receive on the cable going to that system. All signals on this cable are Positive True logic. All levels are differential ECL. At the Receiving End each signal must be terminated with a 110 Ohm resistor across each differential pair of lines. The Sending End of a signal will provide the pull down resistors to Vtt. The Twisted-Flat cable is Spectra-Strip part number 843-132-2801-34. GENERAL PURPOSE TIMING SIGNAL CABLE ------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ----- ----------- -------- ---------- 1 BROWN TIMING SIGNAL 0 NON-INVERTED NTS0 2 TAN TIMING SIGNAL 0 INVERTED ITS0 3 RED TIMING SIGNAL 1 NON-INVERTED NTS1 4 TAN TIMING SIGNAL 1 INVERTED ITS1 5 ORANGE TIMING SIGNAL 2 NON-INVERTED NTS2 6 TAN TIMING SIGNAL 2 INVERTED ITS2 7 YELLOW TIMING SIGNAL 3 NON-INVERTED NTS3 8 TAN TIMING SIGNAL 3 INVERTED ITS3 9 GREEN TIMING SIGNAL 4 NON-INVERTED NTS4 10 TAN TIMING SIGNAL 4 INVERTED ITS4 11 BLUE TIMING SIGNAL 5 NON-INVERTED NTS5 12 TAN TIMING SIGNAL 5 INVERTED ITS5 13 VIOLET TIMING SIGNAL 6 NON-INVERTED NTS6 14 TAN TIMING SIGNAL 6 INVERTED ITS6 15 GREY TIMING SIGNAL 7 NON-INVERTED NTS7 16 TAN TIMING SIGNAL 7 INVERTED ITS7 17 WHITE TIMING SIGNAL 8 NON-INVERTED NTS8 18 TAN TIMING SIGNAL 8 INVERTED ITS8 19 BLACK TIMING SIGNAL 9 NON-INVERTED NTS9 20 TAN TIMING SIGNAL 9 INVERTED ITS9 21 BROWN TIMING SIGNAL 10 NON-INVERTED NTS10 22 TAN TIMING SIGNAL 10 INVERTED ITS10 23 RED TIMING SIGNAL 11 NON-INVERTED NTS11 24 TAN TIMING SIGNAL 11 INVERTED ITS11 25 ORANGE TIMING SIGNAL 12 NON-INVERTED NTS12 26 TAN TIMING SIGNAL 12 INVERTED ITS12 27 YELLOW TIMING SIGNAL 13 NON-INVERTED NTS13 28 TAN TIMING SIGNAL 13 INVERTED ITS13 29 GREEN TIMING SIGNAL 14 NON-INVERTED NTS14 30 TAN TIMING SIGNAL 14 INVERTED ITS14 31 BLUE TIMING SIGNAL 15 NON-INVERTED NTS15 32 TAN TIMING SIGNAL 15 INVERTED ITS15 33 VIOLET GROUNDED AT FRAMEWORK END OPEN AT RECEIVING END 34 TAN GROUNDED AT FRAMEWORK END OPEN AT RECEIVING END 10. AUTOMATICALLY DISABLED SPECIFIC TRIGGER OPTION A Specific Trigger can be programmed so that after firing it will automatically disable itself from generating any more First Level Triggers until it is enabled again by the First Level Trigger Control Computer. The First Level Trigger Control Computer can be instructed by either the Host Computer or the Second Level Trigger Supervisor Computer to reenable a Specific Trigger that has been automatically disabled. 11. SPECIFIC TRIGGERS DISABLED BY THE SECOND LEVEL TRIGGER SUPERVISOR COMPUTER It is necessary for the Second Level Trigger Supervisor Computer to be able to quickly disable a Specific Trigger when the queue of Second Level Trigger Nodes assigned to that Specific Trigger is empty. The signal to disable a certain Specific Trigger will be transmitted over the ALL NODES IN QUEUE ARE BUSY cables. These cables carry 32 signals from the Second Level Trigger Supervisor Computer to the First Level Trigger Framework. When a signal in this cable is in the HIGH ACTIVE state it will disable the Specific Trigger associated with it. The signal must reach the First Level Trigger Framework within 2.9 microseconds after the beam crossing in order to stop a Specific First Level Trigger that could result from that beam crossing. All signals on these two cables are Positive True logic. All levels are differential ECL. At the Receiving End the cable must be terminated with a 110 Ohm resistor across each differential pair of lines. The sending end will provide the pull down resistors to Vtt. The Twisted-Flat cables are Spectra-Strip part number 843-132-2801-34. ALL NODES IN QUEUE ARE BUSY CABLE NUMBER 1 -------------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ----------- 1 BROWN DISABLE SPEC TRIG 1 NON-INVERTED NDSP1 2 TAN DISABLE SPEC TRIG 1 INVERTED IDSP1 3 RED DISABLE SPEC TRIG 2 NON-INVERTED NDSP2 4 TAN DISABLE SPEC TRIG 2 INVERTED IDSP2 5 ORANGE DISABLE SPEC TRIG 3 NON-INVERTED NDSP3 6 TAN DISABLE SPEC TRIG 3 INVERTED IDSP3 7 YELLOW DISABLE SPEC TRIG 4 NON-INVERTED NDSP4 8 TAN DISABLE SPEC TRIG 4 INVERTED IDSP4 9 GREEN DISABLE SPEC TRIG 5 NON-INVERTED NDSP5 10 TAN DISABLE SPEC TRIG 5 INVERTED IDSP5 11 BLUE DISABLE SPEC TRIG 6 NON-INVERTED NDSP6 12 TAN DISABLE SPEC TRIG 6 INVERTED IDSP6 13 VIOLET DISABLE SPEC TRIG 7 NON-INVERTED NDSP7 14 TAN DISABLE SPEC TRIG 7 INVERTED IDSP7 15 GREY DISABLE SPEC TRIG 8 NON-INVERTED NDSP8 16 TAN DISABLE SPEC TRIG 8 INVERTED IDSP8 17 WHITE DISABLE SPEC TRIG 9 NON-INVERTED NDSP9 18 TAN DISABLE SPEC TRIG 9 INVERTED IDSP9 19 BLACK DISABLE SPEC TRIG 10 NON-INVERTED NDSP10 20 TAN DISABLE SPEC TRIG 10 INVERTED IDSP10 21 BROWN DISABLE SPEC TRIG 11 NON-INVERTED NDSP11 22 TAN DISABLE SPEC TRIG 11 INVERTED IDSP11 23 RED DISABLE SPEC TRIG 12 NON-INVERTED NDSP12 24 TAN DISABLE SPEC TRIG 12 INVERTED IDSP12 25 ORANGE DISABLE SPEC TRIG 13 NON-INVERTED NDSP13 26 TAN DISABLE SPEC TRIG 13 INVERTED IDSP13 27 YELLOW DISABLE SPEC TRIG 14 NON-INVERTED NDSP14 28 TAN DISABLE SPEC TRIG 14 INVERTED IDSP14 29 GREEN DISABLE SPEC TRIG 15 NON-INVERTED NDSP15 30 TAN DISABLE SPEC TRIG 15 INVERTED IDSP15 31 BLUE DISABLE SPEC TRIG 16 NON-INVERTED NDSP16 32 TAN DISABLE SPEC TRIG 16 INVERTED IDSP16 33 VIOLET GROUNDED AT SENDING END OPEN AT RECEIVING END 34 TAN GROUNDED AT SENDING END OPEN AT RECEIVING END ALL NODES IN QUEUE ARE BUSY CABLE NUMBER 2 -------------------------------------------- PIN # CABLE COLOR SIGNAL MNEMONIC ------- ------------- -------- ----------- 1 BROWN DISABLE SPEC TRIG 17 NON-INVERTED NDSP17 2 TAN DISABLE SPEC TRIG 17 INVERTED IDSP17 3 RED DISABLE SPEC TRIG 18 NON-INVERTED NDSP18 4 TAN DISABLE SPEC TRIG 18 INVERTED IDSP18 5 ORANGE DISABLE SPEC TRIG 19 NON-INVERTED NDSP19 6 TAN DISABLE SPEC TRIG 19 INVERTED IDSP19 7 YELLOW DISABLE SPEC TRIG 20 NON-INVERTED NDSP20 8 TAN DISABLE SPEC TRIG 20 INVERTED IDSP20 9 GREEN DISABLE SPEC TRIG 21 NON-INVERTED NDSP21 10 TAN DISABLE SPEC TRIG 21 INVERTED IDSP21 11 BLUE DISABLE SPEC TRIG 22 NON-INVERTED NDSP22 12 TAN DISABLE SPEC TRIG 22 INVERTED IDSP22 13 VIOLET DISABLE SPEC TRIG 23 NON-INVERTED NDSP23 14 TAN DISABLE SPEC TRIG 23 INVERTED IDSP23 15 GREY DISABLE SPEC TRIG 24 NON-INVERTED NDSP24 16 TAN DISABLE SPEC TRIG 24 INVERTED IDSP24 17 WHITE DISABLE SPEC TRIG 25 NON-INVERTED NDSP25 18 TAN DISABLE SPEC TRIG 25 INVERTED IDSP25 19 BLACK DISABLE SPEC TRIG 26 NON-INVERTED NDSP26 20 TAN DISABLE SPEC TRIG 26 INVERTED IDSP26 21 BROWN DISABLE SPEC TRIG 27 NON-INVERTED NDSP27 22 TAN DISABLE SPEC TRIG 27 INVERTED IDSP27 23 RED DISABLE SPEC TRIG 28 NON-INVERTED NDSP28 24 TAN DISABLE SPEC TRIG 28 INVERTED IDSP28 25 ORANGE DISABLE SPEC TRIG 29 NON-INVERTED NDSP29 26 TAN DISABLE SPEC TRIG 29 INVERTED IDSP29 27 YELLOW DISABLE SPEC TRIG 30 NON-INVERTED NDSP30 28 TAN DISABLE SPEC TRIG 30 INVERTED IDSP30 29 GREEN DISABLE SPEC TRIG 31 NON-INVERTED NDSP31 30 TAN DISABLE SPEC TRIG 31 INVERTED IDSP31 31 BLUE DISABLE SPEC TRIG 32 NON-INVERTED NDSP32 32 TAN DISABLE SPEC TRIG 32 INVERTED IDSP32 33 VIOLET GROUNDED AT SENDING END OPEN AT RECEIVING END 34 TAN GROUNDED AT SENDING END OPEN AT RECEIVING END 12. TRANSMISSION OF THE FIRST LEVEL TRIGGER DATA BLOCK TO THE SECOND LEVEL TRIGGER The First Level Trigger Data Block is sent from the First Level Trigger Framework to a Second Level Trigger Node over Data Cable number 0. There is no other information that is sent on this Data Cable. The First Level Trigger Framework will send the First Level Trigger Data Block to a memory module in a VME crate. From this memory module the First Level Trigger Data Block passes through a standard VME Dual Output Buffer Module and onto Data Cable number 0. In this way the readout of the First Level Trigger Data Block, and the testing of Data Cable number 0 will look to the Acquisition System like the readout and testing of any of the other detector systems. The standard VME Dual Output Buffer Module will handle all of the timing and synchronization of the Data Cable. 13. COMMUNICATIONS BETWEEN FIRST LEVEL TRIGGER CONTROL COMPUTER, SECOND LEVEL TRIGGER SUPERVISOR COMPUTER, AND THE HOST COMPUTER The First Level Trigger Control Computer, the Second Level Trigger Supervisor Computer, and the Host Computer communicate with each other over a DECnet on Ethernet link. The Host Computer and the First Level Trigger Control Computer will communicate with each other using the following types of messages: LOAD PARAMETERS MESSAGE The Load Parameters Message is sent from the Host to the First Level Trigger Control Computer. This message is the data indicating how the Specific Triggers should be set up. A response to this message must be sent from the First Level Trigger Control Computer to the Host. The response will indicate if the First Level Trigger Control Computer was successful in programming the Specific Triggers as requested and will contain the programming data that the First Level Control Computer has read back from the First Level Trigger. REQUEST PARAMETERS MESSAGE At anytime the Host may request that the First Level Trigger Control Computer read from the First Level Trigger the current parameters of all of the Specific Triggers and the contents of all of the scalers. This information is then sent to the Host. The Request Parameters Message will be used by the Host Computer monitoring routines and in the Host's response to an Alarm Message from the First Level Trigger Control Computer. INITIALIZE MESSAGE The Initialize Message is sent from the Host to the First Level Trigger Control Computer. This message instructs the First Level Trigger Control Computer to reset the Beam Crossing Scalers and the Specific Trigger Scalers, initialize all internal registers in the First Level Trigger, and initialize all internal data structures in the First Level Trigger Control Computer. ENABLE DISABLE MESSAGES These messages are sent from the Host to the First Level Trigger Control Computer. These messages instruct the First Level Trigger Control Computer to enable or disable certain Specific Triggers. Nothing else is changed (the programming of the Specific Triggers is not altered). STOP MESSAGE This message is sent from the Host to the First Level Trigger Control Computer. This message instructs the First Level Trigger Control Computer to disable all Specific Triggers and to stop the Global Beam Crossing Scaler. ALARM MESSAGE This message is sent from the First Level Trigger Control Computer to the Host. This message is sent when the First Level Trigger Control Computer finds that one of the functions that it monitors (e.g. Beam Crossing Scalers and Specific Trigger rates) is out of range or whenever the First Level Trigger Control Computer finds a hardware problem in the First Level Trigger. Part of the Alarm Message is an error code indicating to the Host what the problem is. The First Level Trigger Control Computer and the Second Level Trigger Supervisor Computer can also communicate over the Ethernet link. These messages may include the Second Level Supervisor requesting that certain Specific Triggers be disabled because the number of Second Level Nodes in the queue assigned to handle that type of Specific Trigger is low. The Second Level Supervisor may send a message requesting that a certain Specific Trigger be reenabled after it was disabled automatically. The First Level Trigger Control Computer and the Second Level Trigger Supervisor Computer have no other communication links besides the Ethernet link. 14. COMMUNICATIONS BETWEEN THE TRIGGER FRAMEWORK, THE SECOND LEVEL TRIGGER SUPERVISOR AND THE SECOND LEVEL TRIGGER PROCESSOR NODES The Trigger Framework and the Second Level Trigger Supervisor Computer have one way communication over a special high speed link, the SPECIFIC TRIGGERS FIRED cables. It is by this link that the Trigger Framework quickly informs the Second Level Supervisor which Specific Triggers have fired. It is assumed that the Specific Triggers Fired Cables will terminate with a DRV11-J card in the Second Level Trigger Supervisor Computer. The Trigger Framework and the Second Level Trigger Supervisor Computer also communicate over another special high speed link the ALL NODES IN QUEUE ARE BUSY cables. It is by this link that the Second Level Trigger Supervisor informs the Trigger Framework about which Specific triggers must be disabled because the queue of Second Level Trigger Nodes for that Specific Trigger is empty. It is assumed that this cable will originate in a DRV11-J card in the Second Level Trigger Supervisor computer. The Trigger Framework and the Second Level Trigger Processor Nodes have one way communications over the Data Cable that services the First Level Trigger. It is by this Data Cable link that the First Level Trigger Data Block is quickly sent from the Trigger Framework to a Second Level Trigger Processor. Communications on this link are controlled by a standard VME Data Cable Driver and will follow the Data Cable Standards. The Trigger Framework and the Second Level Trigger Processor Nodes have no other direct communication links besides this one way Data Cable. 15. LIMITATIONS This Trigger Framework has been designed to work with a maximum of 6 bunches in the accelerator. Neither the Trigger Framework nor any of the other parts of the First Level Trigger System are designed to work with a 15 bunch machine. The only communications links that the First Level Trigger Control Computer and the Trigger Framework have with the Second Level Trigger Supervisor, the Second Level Trigger Processor Nodes, and the Host Computer are listed under 14 and 15 above. The speed of communications over the Ethernet link will depend on the load on this link. The delay, using the Ethernet link, to enable or disable a Specific Triggers will have an effect on the dead time for that Specific Trigger. Depending on how the Second Level Trigger Supervisor Computer handles the queues of Second Level Trigger Processor Nodes, there is the possibility that the Acquisition System could hang because there would not be a Second Level Trigger Processor available to handle a certain class of Specific Triggers. 16. FIGURE CAPTIONS Figure 1 Communications Links between the First Level Trigger, the First Level Trigger Control Computer, the Data Acquisition System, the Second Level Trigger Supervisor Computer, The Second Level Trigger, and the Host Computer. Figure 2 First Level Trigger Framework Inputs and Outputs Figure 3 First Level Trigger Framework AND-OR Network