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
• Commanding the server. After establishing a connection with the server, the client
should be able to send a command packet. There are two types of commands in
the system. The first group of commands contains details of the acquisition request.
There are also expert commands which can be sent to the server in order to set its
internal registers. At this point a protocol for the commanding should be designed.
The client’s logic implements this feature. The protocol and the description of all
the types of commands (Acquisition, Expert and Advanced) is presented in Chapter
4.3.1. Furthermore, the description and implementation of the Expert and Advanced
commands is explained thoroughly in Chapters 4.4.6 and 4.4.6.1.
• Data sorting and processing. The server can send both mixed acquisition and sta-
tus/diagnostic data. The protocol should be designed so the data type can be dis-
tinguished and processed accordingly.
In Chapter 4.4.3, we explain the internal distribution process of the two data types.
The acquisition, distribution and processing of the data is done by three different
threads for better performance.
• Displaying in real time two different types of data, acquisition and/or status, for di-
agnostics purposes. This is the main function of the application and the final goal of
the development process.
The online acquisition tab and more precisely the graph component inside it is used
for displaying the acquisition data in real-time. The status data tabs are used for dis-
playing the status elements in parallel with the acquisition data. The refresh rate of
the data in the graphs inside the status tabs is always 1 Hz. For the online graph, the
refresh rate depends always on the measurement period field, but the user should
be careful with this value, because a small measurement period could cause perfor-
mance issues.
We can examine in the following figures, some real-time data coming from a BLEDP
server in the Proton Synchrotron (PS) accelerator facility. Different detectors are
connected in the input of some channels of that system. All the following figures
were captured during an online data transmission.
Figures 33, 34 and 35 illustrate the real-time data-viewing of the two different types of
data, distributed in three tabs, from a single-channel acquisition with a measurement
period of 10000 μs. The type of detector in the acquisition channel of this example
is an ionization chamber.
In Figure 33, the averaged acquisition data plot in the online display is shown. The
observable peaks indicate beam losses produced by the connected detector in chan-
nel 5. Obviously, the different components used for settings manipulation are dis-
abled during an online session. Only the stop button and the Min-Max checkbox are
enabled. Similarly, from the same acquisition, Figures 34 and 35 illustrate the status
Emmanouil I. Angelogiannopoulos 49