BST Pad Detector • Components Primer

Online glossary and Technical documentation

Overview:

Physical components:

1. The Pad Hybrid with pad detector and amplifier/discriminator chips on it and integrated flexible cable extension to the repeater (8 signals, 8 thresholds, 8 supply and operation lines). A total of 64 hybrids are required ( 8 installed, 2 of them being modified for readout of up to 8 analog  signals in 1998 only).

   Performance in H1 and several testruns showed that the preamplifier suffers from large coherent noise of the detectors thus it will be revised throughout this year including a common mode supression circuit.

2. The Pad Repeater processing the data input of two adjacent sectors (8 detectors, thus 64 signals total) in two XILINX 3192A chips. It implements in addition:
   • 64 input receivers, 16 long cable output drivers
   • a Testpulse generator
   • the XILINX configuration bus (8 XILINXs daisy-chained)
   • a Slow Control CAN bus featuring the following slow control functions per repeater:
     • 8 remote controlled ON/OFF switches for detector depletion
     • 8 remote controlled individually adjustable thresholds
     • 8 bias current sensors, remotely read out
     • 3 temperature sensors

   • about 10 supply and auxiliary voltage stabilizers
   • a water cooling and nitrogen flow system

   A total of 8 repeaters are required ( 1 installed, another one for remote bias control and analog readout in 1998 only).

3. The Power/Download Station (PDS) providing the Slow Control-to-Repeater interface for
   • the power distribution (separate IEEE controlled modular power supply)
   • the XILINX configuration and check
   • a configuration identifier (to be stored with the trigger data)
   • the CAN bus transmission (separate VME driven CAN controller)
   • Watch Dog and Alarm Generators for BBL3

   A total of two PDS are required ( 1 installed).

4. The Trigger Card (TC) providing the interface between Repeater and H1 Trigger Signals (Clock, FER, L3Keep...), implementing several phase shifters and auxiliary control signals. A total of two TC are required ( 1 installed).

5. The Master Card (MC) providing the combinational logic for combining the 8 different sector words to a single L1 trigger word. A total of one MC is required ( none installed, for test purposes a simple bypass is set up).

Operation Software:

A few lines of code are implemented in the STC taxi readout to write BST trigger data to the H1 banks:

• SITR contains the TC status and XILINX configuration identifier
• TSCD contains the repeater output for the last 24 bunch crossings at a triggered event.

The Frontend Data Reduction Algorithms implemented in the XILINXs are being designed offline using a schematic editor and a commercial development system. They are coded to bit-serial data stream files to which a unique identifier is added upon configuring the system in H1.

Back to the Shift Instructions. To the BST site.