Design and Development of a Diagnostics Client for a Beam Loss ...

Design and Development of a Diagnostics Client for a Beam Loss Measurement System at CERN
range and maximum linear response of each channel and check frequently the complete
channel’s connection. [19]
In Figure 3 below, the Acquisition Crate and some of its Technical elements are shown.
Figure 3: Acquisition Crate’s Elements
The detailed description of the elements is not part of this thesis. Complete information
about these technical elements of the Beam Loss Electronic Acquisition Crate can be
found in the corresponding notes. [14]
3.2.2 Beam Loss Electronic Dual Polarity (BLEDP)
The BLEDP is the Beam Loss Electronic Dual Polarity Card. It is the most important part of
the BLEAC and its aim is to measure with high precision the current produced by the Beam
Loss Monitors. The crate can host up to 8 BLEDP cards. The BLEDP card contains an
Altera Cyclone IV GX FPGA in which a Nios II soft processor is implemented. The server
application implemented in this processor is written in C. Each card can acquire up to 8
input channels, so the total of input channels available on the crate can sum up to 64 (8x8).
In addition, each card has an Ethernet Link, in order to be able to connect with the network
for external diagnosis. The diagnostics client communicates with the cards through this
link. The card implements two types of measurement: (i) The Fully Differential Frequency
Converter (FDFC) and (ii) The Direct Acquisition Data Converter (DADC). Both methods
produce raw digitized input at different rates:
• In the FDFC mode, the input current is integrated during 2μs period. The integrator
produce count pulses which are combined with ADC values to provide precise digital
values at 0.5 MSPS rate (i.e. one sample every 2μs).
• In the DADC mode the input current is converted into ADC values with the same
conversion frequency of 0.5 MSPS (i.e. one sample every 2 μs).
Emmanouil I. Angelogiannopoulos 18