cppVisa - Modern C++ Wrapper for National Instrument VISA

Description

A C++23 library that wraps the NI VISA API. The idea is to use NI VISA library easily without all the C boilerplate. Supports USBTMC, Ethernet (VXI-11/HiSLIP), Serial (RS-232), and GPIB.

Features

✅ Architecture

• A pointer to implementation hide details (cppVisaImpl)for a clean header. Refer to pimpl for documentation.

✅ Supported Protocols

1. USB - Communication via USB-TMC
2. Ethernet (ETH) - TCP/IP communication with VXI-11 or HiSLIP
3. Serial (COM) - RS-232 serial communication
4. GPIB - IEEE-488 communication

NI VISA Specifics

USB Protocol:

• Timeout configuration (VI_ATTR_TMO_VALUE)

COM Protocol (Serial):

• Baud rate configuration (VI_ATTR_ASRL_BAUD)
• Data bits configuration (VI_ATTR_ASRL_DATA_BITS)
• Stop bits configuration (VI_ATTR_ASRL_STOP_BITS)
• Parity configuration (VI_ATTR_ASRL_PARITY)

Ethernet Protocol:

• Timeout configuration
• Termination character configuration (VI_ATTR_TERMCHAR)
• Enable termination character detection (VI_ATTR_TERMCHAR_EN)

GPIB Protocol:

• Timeout configuration
• viClear() - Bus clearing

Usage

Basic Example

#include "cppVisa.h"

int main()
{
    // USB Connection
    cppVisa visa({
        .address = "USB0::0x1AB1::0x0588::DS1ZA170000000::INSTR",
        .timeout = 5000,
        .protocol = PROTOCOL::USB
    });

    if (visa.connect()) {
        visa.write("*IDN?");
        
        std::string response;
        visa.read(response);
        std::cout << "Instrument ID: " << response << "\n";
        
        visa.disconnect();
    }

    return 0;
}

Protocol-specific Examples

USB

cppVisa visaUsb({
    .address = "USB0::0x1AB1::0x0588::DS1ZA170000000::INSTR",
    .timeout = 5000,
    .protocol = PROTOCOL::USB
});

Ethernet (TCPIP)

cppVisa visaEth({
    .address = "TCPIP0::192.168.1.100::inst0::INSTR",
    .timeout = 3000,
    .protocol = PROTOCOL::ETH
});

Serial (COM)

cppVisa visaCom({
    .address = "ASRL1::INSTR",
    .timeout = 2000,
    .protocol = PROTOCOL::COM
});

GPIB

cppVisa visaGpib({
    .address = "GPIB0::10::INSTR",
    .timeout = 4000,
    .protocol = PROTOCOL::GPIB
});

Post-construction Customization

cppVisa visa({...});

// Change timeout after creation
visa.setTimeout(10000);
uint32_t currentTimeout = visa.getTimeout();

// Change address
visa.setAddress("TCPIP0::192.168.1.101::inst0::INSTR");
std::string currentAddress = visa.getAddress();

// Get protocol type
PROTOCOL proto = visa.getProtocol();

Public API

Constructor

cppVisa(configVISA config);

Communication Methods

bool connect();                          // Open connection
bool disconnect();                       // Close connection
bool write(const std::string& command);  // Send a command
bool read(std::string& response);        // Read a response

Configuration Methods

void setTimeout(uint32_t timeout);       // Change timeout (ms)
void setAddress(const std::string& address); // Change address
uint32_t getTimeout() const;             // Get timeout
std::string getAddress() const;          // Get address
PROTOCOL getProtocol() const;            // Get protocol

Error Handling

Errors are automatically displayed with:

• The name of the failed operation
• A descriptive VISA error message
• The error code in hexadecimal

Dependencies

• NIVISA : NI-VISA library (visa64.lib)
• C++ Standard : C++23
• CMake : Minimum version 3.8

Build

cmake -B build -G Ninja
cmake --build build

Technical Notes

License

LGPL-2.1-or-later

Author

Alexandre CARPENTIER