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0v0. Summary. Brief Summary about Permit Loops Beam Permit Loop Frequency Generator (CIBG) Optical Transceiver (CIBO). BRIEF SUMMARY ABOUT BEAM PERMIT LOOPS. Permit Loops. Permit Loops. A single generator is used in the whole loop The frequency is not regenerated at any point
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Summary • Brief Summary about Permit Loops • BeamPermitLoopFrequencyGenerator (CIBG) • OpticalTransceiver (CIBO) Generators and Detectors
BRIEF SUMMARY ABOUT BEAM PERMIT LOOPS Generators and Detectors
Permit Loops Generators and Detectors
Permit Loops • A single generator is used in the whole loop • The frequency is not regenerated at any point • Avoid failures that could force the permit loop to be maintained regardless of the actual state of the USER_PERMIT signals. • Frequencies chosen 8 – 10 MHZ • Allow rapid response. • Not harmonics with any known frequency in any CERN accelerator. • In the case of the LHC: • One loop anticlockwise (A) and One loop clockwise (B) • A : 9.375 MHz / B: 8.375 • The signal is repeated 18 times and travels aprox 45 kms. Generators and Detectors
Beam Permit Loop General Layout • CIBG is responsible for the generation of the BEAM_PERMIT freq. • Any USER_SYSTEM can break the frequency loop through a USER_PERMIT triggered to the corresponding Beam Interlock Controller. • If the frequency appears at the end BEAM_PERMIT TRUE • In the LHC Reaction time ~ 120 μ s A B Generators and Detectors
CIBG (Beam Permit Loop Frequency Generator card) Generators and Detectors
CIBG – I/O Generators and Detectors
CIBG – Hardware Implementation Generators and Detectors
CPLD GENERATOR CIRCUITS Rx Tx Generators and Detectors
CIBG – Frequency characteristics • Output frequency accuracy: Test freq Generators and Detectors
CIBG – Frequency characteristics • Input frequency accuracy: • Slow detector (Nominally A: 9.375 MHz / B: 8.375 MHz) • It activates when the integrity of the optical link degrades over time. • It counts the number of edges sent in several hundred microseconds. • Slow detect: ± 5% error / Measures takes 100 ms. • And compares to the following boundaries. Generators and Detectors
CIBG – Frequency characteristics • Input frequency accuracy: • Fast detector (Nominally A: 9.375 MHz / B: 8.375 MHz) • It observes the link for a few 100ths of ns. • Detects the change in link state due to a real request for Beam Dump • Fast detect : ± 10% error / Measures takes 3-4 μs. Generators and Detectors
CIBG – Additional Information • You can find all detailed schematics, pcb layouts and electrical characteristics about the CIBO in sections #12 and #16 of the folder provided . Generators and Detectors
CIBO (OpticalTransceiver) Generators and Detectors
CIBO CERN, the LHC and Machine Protection
CIBO – Block diagram -15 to -25 dBm Output TTL 1310 nm Singlemode -36 to -39 dBm Sensitivity CIBO P(Fail) per Hour CERN, the LHC and Machine Protection
CIBO – Additional Information • You can find all detailed schematics, pcb layouts and electrical characteristics about the CIBO in sections #20 of the folder provided. Generators and Detectors
FIN CERN, the LHC and Machine Protection