BNL, Upton, New York, USA
There are a variety of beam current transformers that are used at all accelerator facilities for current and bunch charge measurements. Transformer signals are traditionally measured using integrator electronics followed by a digitizer. However, integrator circuits have a limited bandwidth and are susceptible to noise. By directly digitizing the output of the transformer, the signal bandwidth is limited only by the transformer characteristics and the digitizing platform. Digital integration and filtering can then easily be applied to reduce noise resulting in an overall improvement of the beam parameter measurements. This paper describes a Python-based application that performs the filtering and integration of a current transformer pulse that has been directly digitized by an oscilloscope.
BNL, Upton, New York, USA
This paper reports on development of a general purpose image analysis application, tailored for beam profile monitor cameras of RHIC Collider-Accelerator complex. ImageViewer is pure Python application, based on PyQtGraph and SciPy packages. It accepts image stream from a RHIC image manager (optionally from an EPICS areaDetector driver, or from the file system). The standard analysis includes recognition of connected objects; for each object the parameters of a fitted ellipsoid (position, axes and tilt angle) are calculated using 2nd-order image moments, the parameters then corrected using gaussian fit of the object and a surrounding background. Other features supported: saving, image rotation, region of interest, projections, subtraction of a reference image, multi-frame averaging, pixel to millimeter calibration. Playback feature allows for fast browsing and cleanup of the saved images. User add-ons can be added dynamically as included modules. Each camera of the RHIC complex is equipped with a server (grahic-less) version of this application, providing the same analysis and publishing calculated parameters to RHIC Controls Architecture.
BNL, Upton, New York, USA
The BNL CA-D controls environment has recently been adopting modern programming languages such as Python. A new framework has been created to instantiate setting and measurement parameters in Python as an alternative to C++ and Java process-variable-like objects. With the help of automated testing tools such as pyTest and Coverage, a test suite is generated and executed before the release of Python-based accelerator device objects (ADO) to assure quality as well as compatibility. This suite allows developers to add custom tests, repeat failed tests, create random inputs, and log failures.
BNL, Upton, New York, USA
Modern instruments are often supplied with rich proprietary software tools, which makes it difficult to integrate them to an existing control systems. The liteServer is very lightweight, low latency, cross-platform network protocol for signal monitoring and control. It provides very basic functionality of popular channel access protocols like CA or pvAccess of EPICS. It supports request-reply patterns: ’info’, ’get’ and ’set’ requests and publish-subscribe pattern: ’monitor’ request. The main scope of the liteServer is: 1) provide control and monitoring for instruments supplied with proprietary software, 2) provide fastest possible Ethernet transactions, 3) make it possible to implement in FPGA without CPU core. The transport protocol is connection-less (UDP) and data serialization format is Universal Binary JSON (UBJSON). The UBJSON provides complete compatibility with the JSON specification, it is very efficient and fast. A liteServer-based system can be connected to existing control system using simple bridge program (bridges for EPICS and RHIC Ado are provided).
