PVXS client/server for PVA Protocol

This module provides a low-level PVAccess protocol Client API, Server API, a set of CLI utilities, as well as high-level integration with the EPICS IOC Process Database (aka. QSRV 2)

• VCS: https://github.com/epics-base/pvxs

• Docs: https://epics-base.github.io/pvxs

• Issues (see Reporting a Bug)

• Contributing

Dependencies

• A C++11 compliant compiler

• GCC >= 4.8

• Visual Studio >= 2015 / 12.0

• clang

• EPICS Base >=3.15.1

• libevent >=2.0.1 (Optionally bundled)

• (optional) CMake >=3.10, only needed when building bundled libevent

Download

Releases are published to https://github.com/epics-base/pvxs/releases. See Release Policy for details.

Getting Started

See Building from Source, and Including PVXS in your application.

With QSRV2 included, all local database records will be served via PVA. For most user IOCs, no further action is necessary.

Contents

• Overview
  • Basics
    • What is EPICS?
    • What is PVAccess?
    • What is a PV?
  • PVXS Module
  • Comparison with pvDataCPP
    • Sub-field Lookup
    • Structure Iteration
    • Testing for changed fields
    • Tracking changed fields
    • NTScalar
    • Custom Structures
  • Comparison with pvAccessCPP
• PVA Network Configuration
  • Big Picture
  • Environment variables
  • Address Spec.
• Examples
  • Shortest Client Get
  • Shortest Server
  • Client Demo
  • Mailbox Server
• Building from Source
  • Running Tests
  • Cross-compiling libevent2
• Including PVXS in your application
• Command Line Tools
  • Troubleshooting with Virtual Cable Tester
• IOC Integration
  • IOC shell
    • pvxsr()
    • pvxsl()
    • pvxsi()
  • Adding custom PVs to Server
    • server()
• QSRV 2
  • Functionality
    • IOC Shell
    • Single PV
    • Group PV
    • Access Security
    • PVAccess Links
• Value Container API
  • Common Type Definitions
    • NTScalar and NTScalarArray
    • Forward Compatibility
    • time_t
    • alarm_t
    • NTEnum
    • NTNDArray
    • NTTable
    • NTURI
  • Defining Custom Types
    • TypeCode
    • TypeDef
    • Member
    • members
    • Kind
  • Value
    • Field Lookup
    • Iteration
  • Array fields
    • shared_array
    • elementSize()
    • Limiter
    • ArrayType
• Client API
  • Configuration
  • Making Requests
    • Context
    • Get/Info
    • Put
    • RPC
    • Operation and Result
    • Monitor
    • Connect
    • Threading
    • Ownership
  • pvRequest
    • CommonBuilder
    • Syntax
  • Misc
    • Config
    • Connected
    • Disconnect
    • Finished
    • RemoteError
• Server API
  • SharedPV and StaticSource
    • SharedPV
    • StaticSource
  • Data Source
    • Threading
    • Ownership and Lifetime
    • API
  • Configuration
    • Config
    • Server
• Misc
  • Logging
    • Level
    • Controlling Logging
    • Logging from User applications
  • Identification
    • version_int()
    • version_str()
    • version_abi_int()
    • version_abi_check()
  • Unit-test helpers
    • testThrows()
    • testThrowsMatch()
    • testCase
    • IOC Testing
  • Utilities
    • escape()
    • escape()
    • escape()
    • cleanup_for_valgrind()
    • SigInt
    • target_information()
    • MPMCFIFO
• Details
  • Reporting a Bug
    • Packet Capture
  • Release Policy
  • Expert APIs
  • Contributing
    • Contributors
  • Implementation Notes
• Release Notes
  • 1.4.0 (July 2025)
  • 1.3.3 (Apr 2025)
  • 1.3.2 (Oct 2024)
  • 1.3.1 (Dec 2023)
  • 1.3.0 (Dec 2023)
  • 1.2.4 (Oct 2023)
  • 1.2.3 (Sept 2023)
  • 1.2.2 (June 2023)
  • 1.2.1 (June 2023)
  • 1.2.0 (May 2023)
  • 1.1.4 (April 2023)
  • 1.1.3 (Mar 2023)
  • 1.1.2 (Feb 2023)
  • 1.1.1 (Dec 2022)
  • 1.1.0 (Nov 2022)
  • 1.0.1 (Oct 2022)
  • 1.0.0 (Sept 2022)
  • 0.3.1 (June 2022)
  • 0.3.0 (May 2022)
  • 0.2.2 (Jan 2022)
  • 0.2.1 (Oct 2021)
  • 0.2.0 (July 2021)
  • 0.1.5 (May 2021)
  • 0.1.4 (APR 2021)
  • 0.1.3 (FEB 2021)
  • 0.1.2 (FEB 2021)
  • 0.1.1 (Jan 2021)
  • 0.1.0 (Dec 2020)

Indices and tables

• Index

• Module Index

• Search Page

This document describes version 1.4.0-3-g3727052 and earlier.