# visa-rs
[](https://crates.io/crates/visa-rs)
[](https://docs.rs/visa-rs)
Safe Rust bindings for VISA(Virtual Instrument Software Architecture) library
Most documentation comes from [NI-VISA Product Documentation](https://www.ni.com/docs/en-US/bundle/ni-visa-20.0/page/ni-visa/help_file_title.html)
## Requirements
This crate needs to link to an installed visa library, for example, [NI-VISA](https://www.ni.com/en-us/support/downloads/drivers/download.ni-visa.html).
A default link configuration is used for the default installation setup on Windows, Linux and MacOs.
You can overwrite the configuration by specifying the name of the visa library file (`visa` for linux, `visa64` or `visa32` for windows) by environment variable `LIB_VISA_NAME`, and the path of the file by environment variable `LIB_VISA_PATH`.
## Example
Add dependencies below to `Cargo.toml`
```toml
[dependencies]
visa_rs = { git = "https://github.com/TsuITOAR/visa-rs.git" }
```
Codes below will find the first Keysight instrument in your environment and print out its `*IDN?` response.
```rust
fn find_an_instr() -> visa_rs::Result<()>{
use std::ffi::CString;
use std::io::{BufRead, BufReader, Read, Write};
use visa_rs::prelude::*;
// open default resource manager
let rm: DefaultRM = DefaultRM::new()?;
// expression to match resource name
let expr = CString::new("?*KEYSIGH?*INSTR").unwrap().into();
// find the first resource matched
let rsc = rm.find_res(&expr)?;
// open a session to the resource, the session will be closed when rm is dropped
let instr: Instrument = rm.open(&rsc, AccessMode::NO_LOCK, TIMEOUT_IMMEDIATE)?;
// write message
(&instr).write_all(b"*IDN?\n").map_err(io_to_vs_err)?;
// read response
let mut buf_reader = BufReader::new(&instr);
let mut buf = String::new();
buf_reader.read_line(&mut buf).map_err(io_to_vs_err)?;
eprintln!("{}", buf);
Ok(())
}
```
License: MIT OR Apache-2.0