sf-daq/sf_daq_buffer
0
0
Fork 0
mirror of https://github.com/paulscherrerinstitute/sf_daq_buffer.git synced 2026-04-21 14:44:36 +02:00
Code Issues Packages Projects Releases Wiki Activity
1,709 Commits 7 Branches 4 Tags
a94010aaf8a56e4f32b6cb51709ec8207aefbf58
T
Clone
Open with VS Code Open with VSCodium Open with Intellij IDEA
Download ZIP Download TAR.GZ Download BUNDLE

README.md

sf_daq_buffer

Overview of current architecture and component interaction.

Overview image

Documentation of individual components:

  • sf-buffer (Receive UDP and write buffer files)

Useful links

Architecture

Software

Linux configuration

Build

To compile this repo you will need to install the following packages on RH7:

  • devtoolset-9
  • cmake3
  • zeromq-devel
  • hdf5-devel
yum install devtoolset-9
yum install cmake3
yum install zeromq-devel
yum install hdf5-devel

Step by step procedure to build the repo:

scl enable devtoolset-9 bash
git clone https://github.com/paulscherrerinstitute/sf_daq_buffer.git
cd sf_daq_buffer
mkdir build
cd build/
cmake3 ..
make

It is recommended to create symbolic links to the executables you will be using inside your PATH.

Example:

ln -s "$(pwd)""/""sf_buffer" /usr/bin/sf_buffer
ln -s "$(pwd)""/""sf_stream" /usr/bin/sf_stream
ln -s "$(pwd)""/""sf_writer" /usr/bin/sf_writer

Warnings

Zeromq

Zeromq version 4.1.4 (default on RH7) has a LINGER bug. Sometimes, the last message is not sent (the connection gets dropped before the message is in the buffer). Since we use PUSH/PULL to modulate the sf_replay speed, this is a key functionality we are using.

Please install a later version:

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/network:messaging:zeromq:release-stable/RHEL_7/network:messaging:zeromq:release-stable.repo
yum remove zeromq
yum remove openpgm
yum install libsodium-devel
yum install zeromq-devel

Terminology

In order to unify the way we write code and talk about concept the following terminology definitions should be followed:

  • frame (data from a single module)
  • image (data of the assembled image)
  • start_pulse_id and stop_pulse_id (not end_pulse_id) is used to determine the inclusive range (both start and stop pulse_id are included) of pulses.
  • pulse_id_step (how many pulses to skip between images).
  • detector_folder (root folder of the buffer for a specific detector on disk)
  • module_name (name of one module inside the detector_folder)
  • data_folder (folder where we group more buffer files based on pulse_id range)

Data request ranges

Data request ranges are composed of:

  • start_pulse_id (first pulse_id to be included in the file)
  • stop_pulse_id (last pulse_id to be included in the file)
  • pulse_id_step (how many pulses to skip between images.)

pulse_id_step can be used to write data at different frequencies:

  • pulse_id_step == 1 (100Hz, write very pulse_id)
  • pulse_id_step == 2 (50hz, write every second pulse)
  • pulse_id_step == 10 (10Hz, write every 10th pulse)

The next pulse_id to be written is calculated internally as:

auto next_pulse_id = currnet_pulse_id + pulse_id_step;

The loop criteria for writing is:

for (
        auto curr_pulse_id = start_pulse_id; 
        curr_pulse_id <= stop_pulse_id;
        curr_pulse_id += pulse_id_step
) {
    // Write curr_pulse_id to output file.
}

Warning

If your stop_pulse_id cannot be reached by adding step_pulse_id to start_pulse_id (start_pulse_id + (n * pulse_id_step) != stop_pulse_id for any n) it will not be included in the final file.

Reference in New Issue View Git Blame Copy Permalink
S
Description
No description provided
daqjungfrauswissfel
Readme 3.2 MiB
Languages
C++ 91.1%
Python 4.9%
CMake 3.2%
Dockerfile 0.4%
Shell 0.4%