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
count number request refers also to data bundles, even though UDP has no restriction for
the payload size of the datagrams. This is for simplicity reasons. In Figure 10, a BLEDP
bundle of size 350 and one of its acquisition frames is shown.
4.3.3 Data Sent by the Server
Figure 10: BLEDP bundle and Acquisition frame
There are two types of data sent by the embedded server inside the BLEDP cards. The
first type is the acquisition data frames stored inside fixed-size buffers (bundles) as already
mentioned in the previous chapter. The second type is the status data frames. This type is
also transmitted inside fixed-size buffers and is interleaving in parallel with the acquisition
data from the established TCP socket.
4.3.3.1 BLEDP Acquisition Frame
The BLEDP acquisition frame is the main packet produced by the FPGA and sent by the
embedded server. The monitoring of these packets is the main goal of the design and
development process of the client application.
In the final operating version of the system, several beam loss detectors like secondary
emission monitors, diamonds, Cherenkov detectors and ionization chambers are going
to be connected to the input of the acquisition system. The system makes use of two
measurement acquisition methods, described in the corresponding chapters, and pro-
duces digital processed data out of the analog input signal. One processed data frame
is produced every 2 μs for each of the 8 acquisition channels. The embedded server
“talks” directly to the hardware enabling the transmission of these acquired processed
data points.
Each processed data frame is acquired and manipulated by the embedded server into a
32-bit integer point with header, sequence number and payload. There are 6 bits com-
posing the header with 3 types of information. Subsequently, there are 6 bits of sequence
after the header for the processed data. These bits indicate an incremental counter value
for debugging purposes. The range of this number goes up to its maximum value and then
rolls back to 0. Lastly, the next bits indicate the payload value. The detailed information
about the BLEDP acquisition packet structure is shown in table 1.
Emmanouil I. Angelogiannopoulos 26