Using PVSS for the control of the LHCb

Using PVSS for the control of the LHCb TELL 1 detector emulator (OPG) P. Petrova, M. Laverne, M. Muecke, G. Haefeli, J. Christiansen CERN European Organization for Nuclear Resarch

Outline • Data Acquisition for LHCb – System overview – TELL 1 – OPG • SCADA&PVSS – Use of SCADA tools in control applications – What is PVSS? • GUI-control for OPG – – – Configuration panel set DIM Why GUI? PVSS challenges Design problems • Summary and conclusions TELL 1 - OPG Control 2

Data Acquisition for LHCb DAQ system overview TELL 1 - OPG Control 3

TELL 1 board overview TELL 1 is an FPGA based readout board, part of the off-detector acquisition electronics used in the LHCb experiment TELL 1 board TELL 1 - OPG Control 4

TELL 1 - functions • • • TELL 1 is a receiver card for the analogue or optical data from the detector front-end electronics It provides basic signal processing and filtering of the subdetector signals TELL 1 is designed to accept input “mezzanine” cards for both copper and optical link configurations, requested by the different subsystems. It performs Level 1 (L 1) buffering and interfacing to the Level 1/High Level Trigger (L 1/HLT) Connects to the HLT via Gigabit Ethernet network TELL 1 is controlled by ECS (Experiment Control System) via a “Credit– Card PC” (CCPC) Via a “Glue. Card” PCI bridge the CCPC connects to 3 different buses On-board are used 3 types of buses: Parallel Local Bus, JTAG and I 2 C The TELL 1 board is planned to perform intensive processing of the input dataflow from the seven different LHCb detectors TELL 1 - OPG Control 5

OPG • OPG – Optical Pattern Generator • It emulates the subdetector output signals of the six subdetectors using optical links with their specific format • OPG boards exist for use with optical links only • Emulated signal parameters – pattern files – configuration database - shorter configuration time, unification of the test patterns and possible reuse of the same parameterization • OPG has the same control as TELL 1 via CCPC and Glue. Cards TELL 1 - OPG Control 6

SCADA for control • SCADA (Supervisory Control and Data Acquisition) systems • used in industrial and engineering applications for monitoring and control of distributed systems from a master location • focus on supervising • purely software package that is positioned on top of hardware to which it interfaces. • used in industry and experimental physics laboratories • rely on various functionality, scalability, performance and openness • alternative to “in-house” developed packages, even for very demanding and complex control systems as those of physics experiments TELL 1 - OPG Control 7

What is PVSS? • PVSS II is one of the existing industrial SCADA applications, produced by the Austrian company ETM. • PVSS can connect to hardware (or software) devices, acquire the data they produce and use it for their supervision • It can monitor devices’ behaviour and initialize, configure and operate them • PVSS can run in a distributed manner – as one single system – as various interconnected systems • It has multi-platform support (Linux and Windows). TELL 1 - OPG Control 8

PVSS features • PVSS provides development environment with Human Machine Interface (HMI) and scripting/API (Application Programming Interface) capabilities • • TELL 1 - OPG Control It has mechanisms for: – alarm handling – access control – archiving – trending Provides various interfaces and drivers (OPC, Profi. Bus, Can. Bus, Modbus TCP/IP and Applicom) to external hardware and software Some additional interfaces (like DIM extended for CCPC/SPECS) - developed at CERN JCOP Framework for PVSS 9

PVSS Data. Points • A key SCADA/PVSS concept is the data point (DP) • In PVSS every object is modeled using data point types • Data point type is collection of data point elements. It’s analogous to an object oriented class with attributes, that provides inheritance. • What is the Data. Point? - Data points are particular instances of a data point type Device/signals correspondence TELL 1 - OPG Control 10

Example Data. Point Example of a DP Structure as device representation TELL 1 - OPG Control 11

GUI Control • GUI (Graphical User Interfface) • The best way of presenting control information to the user • It gives the easiest and fastest way of communication with the hardware • The graphical environment masks all hardware processes and the user interacts with the system via simple commands • Important feature of the GUI implementation - it “hides” the real system that stands behind it • No detailed knowledge of the hardware on the user side required for the communication • Via GUI-based control all devices in the network can be displayed at the same time, as well as their features TELL 1 - OPG Control 12

OPG Control panels • OPG control constists of a set of five panels created in the PVSS environment • They are used for configuration and control of the board • They show dynamically updated graphics, representing the feedback of the entered dataflow configuration • Two of the panels are for OPG parameterization and visualization of the entered values (Fragment Definition, Package Visualization) Fragment definition panel TELL 1 - OPG Control 13

OPG Control panels • The graphics display is constantly updated when a change in the monitored parameters is detected • This change might be due to user new entries or to hardware feedback • Most of the monitored parameters are part of the board configuration Header visualization TELL 1 - OPG Control 14

OPG Control panels • • • Additional panel exists, in which is displayed the signal pattern file, currently used by the OPG board The signal pattern file could be modified through it The changes in this panel update the other visual information displays Configuration visualization TELL 1 - OPG Control 15

OPG Control panels • • The “OPG Control” panel uses DIM server (DIM DNS node) connection for getting the available in the network OPG and TELL 1 board names The user can identify the type of any of the boards, if it’s OPG or TELL 1 The mechanism of the routine is based on a JTAG chain scan of the selected board The panel provides additional functionalities to be executed for the selected devices: – downloading/uploading of the FPGAs configuration information – monitoring of several dataflow parameters OPG Control panel TELL 1 - OPG Control 16

DIM • DIM is a communication mechanism running on several platforms • PVSS-DIM toolkit is an add-on software, which allows the interface of PVSS to devices which do not provide any of the PVSS supported protocols • The basic concept in the DIM approach is the concept of "service“ • Usually all CCPCs (mounted on TELL 1 or OPG), register as services to one of the provided DIM servers. • Thus the information about their status and functionalities becomes available to the possible clients, interested in them TELL 1 - OPG Control 17

Why GUI? • Advantages: – simplifies the user-to-hardware communication – allows simultaneous monitoring of several devices or interconnected systems – makes possible distant system maintenance – possible comparison and cross-references – possibility for representing even complex architectures in an intuitive and “obvious” way – speeds up and makes easier the process of setting up the necessary input values – gives simultaneous feedback with the system response to new settings – reduces the time for getting used to the new hardware – increases usability TELL 1 - OPG Control 18

PVSS challenges and design problems PVSS has some restrictions that make the realization of the GUI difficult and not very nice looking • Active. X functions – Microsoft technology vs. Linux – Unwanted slow-down due to real time graphics rendering • Control scripts – – – PVSS custom programming language CTRL Script functions’ imperfections Limited function set Limited variable types and use DP oriented programming algorithms Some additional constraints arise from the DAQ electronics requirements and CERN software compatibility policy TELL 1 - OPG Control 19

Conclusions • The presented GUI for OPG boards control has shown to be a good approach for implementing the needed supervisory tools • Although in the process of realization in the PVSS environment the initial idea went through several major transformations, due to many toolkit constraints – mainly on the visual part, the result is satisfying and meets the predefined goals. • Most of the graphics have been elaborated with custom made scripts. Although this is slowing down the development process, it makes the GUI executable under both Windows and Linux environment. This is essential requirement for all CERN control systems. TELL 1 - OPG Control 20