s7

A simple library that can be used to communicate with Siemens S7 family PLC devices

This crate provides communication tools for Siemens s7 family devices So far only PG.db_read and PG.db_write have been tested on actual hardware The crate is unstable as of now and provides no guarantees

examples

extern crate s7;

use s7::{client::Client, field::Bool, field::Fields, field::Float, tcp, transport::Connection};
use std::net::{IpAddr, Ipv4Addr};
use std::time::Duration;

fn main() {
   let addr = Ipv4Addr::new(127, 0, 0, 1);
   let mut opts = tcp::Options::new(IpAddr::from(addr), 5, 5, Connection::PG);

   opts.read_timeout = Duration::from_secs(2);
   opts.write_timeout = Duration::from_secs(2);

   let t = tcp::Transport::connect(opts).unwrap();
   let mut cl = Client::new(t).unwrap();

   let buffer = &mut vec![0u8; Bool::size() as usize];
   let db = 888;

   // the offset in the PLC is represented by a float
   // the difit on the left is the index within the block
   // the digit after the decimal point is only important for the `Bool` to be able to change the relevant bit
   // we don't need after
   let mut offset = 8.4;

   // Since this is a boolean field, we are going to get back 1 byte
   cl.ag_read(db, offset as i32, Bool::size(), buffer).unwrap();

   // field mod provides types to handle the data from the PLC
   // create a bool field from the byte we got
   let mut lights = Bool::new(db, offset, buffer.to_vec()).unwrap();

   // the bit in the byte is set without changing any of the other bits
   lights.set_value(!lights.value()); // toggle the light switch

   offset = 12.0;
   let mut cooling_buffer = vec![0u8; Float::size() as usize];
   cl.ag_read(db, offset as i32, Float::size(), cooling_buffer.as_mut())
       .unwrap();
   let mut cooling = Float::new(db, offset, cooling_buffer).unwrap();
   cooling.set_value(121.3);

   let fields: Fields = vec![Box::new(lights), Box::new(cooling)];

   // save back the changed values
   for field in fields.iter() {
       cl.ag_write(
           field.data_block(),
           field.offset(),
           field.to_bytes().len() as i32,
           field.to_bytes().as_mut(),
       )
       .unwrap();
   }
}

License

Copyright 2019 Petar Dambovaliev. All rights reserved. This software may be modified and distributed under the terms of the BSD license. See the LICENSE file for details.