main.cpp

/**
 * @brief libmodbuspp router-json example
 *
 * Shows how to use libmodbuspp to build a MODBUS time server.
 * the MODBUS router is configured from a JSON file
 *
 * @code
 * router-json json_filename
 * @endcode
 *
 * Once the router has started you can test it with mbpoll :
 *
 * @code
    $ mbpoll -mtcp -p1502 -a10 -t3 -c8 localhost
    mbpoll 1.4-12 - FieldTalk(tm) Modbus(R) Master Simulator
    Copyright © 2015-2019 Pascal JEAN, https://github.com/epsilonrt/mbpoll
    This program comes with ABSOLUTELY NO WARRANTY.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type 'mbpoll -w' for details.

    Protocol configuration: Modbus TCP
    Slave configuration...: address = [10]
                            start reference = 1, count = 8
    Communication.........: localhost, port 1502, t/o 1.00 s, poll rate 1000 ms
    Data type.............: 16-bit register, input register table

    -- Polling slave 10... Ctrl-C to stop)
    [1]:  37
    [2]:  40
    [3]:  15
    [4]:  28
    [5]:  11
    [6]:  2019
    [7]:  4
    [8]:  332
 * @endcode
 *
 * These data correspond to 15:40:37 on Thursday 28/11/2019, 332nd day of the
 * year. To read the time difference from GMT (in seconds) :
 *
 * @code
    $ mbpoll -mtcp -p1502 -a10 -t4:int -B -1 localhost
      ....
      -- Polling slave 10...
      [1]:  3600
 * @endcode
 *
 * To set the offset to GMT-2 hours :
 *
 * @code
    $ mbpoll -mtcp -p1502 -a10 -t4:int -B localhost -- -7200
      ....
      Written 1 references.
 * @endcode
 */
#include <csignal>
#include <thread>
#include <iostream>
#include <modbuspp.h>

using namespace std;
using namespace Modbus;

Router router; // instantiates new MODBUS Router

// -----------------------------------------------------------------------------
// Signal trap, triggers during a CTRL+C or if kill is called
void
sighandler (int sig) {

  router.close();
  cout << "everything was closed." << endl << "Have a nice day !" << endl;
}

// -----------------------------------------------------------------------------
int main (int argc, char **argv) {

  if (argc < 2) {

    cerr << "Error: the JSON filename must be provided as a parameter on the command line !" << endl;
    cerr << "e.g. : " << argv[0] << " router-tcp-rs232.json" << endl;
    exit (EXIT_FAILURE);
  }

  string  jsonfile = argv[1];

  cout << "--- Json Modbus Router ---" << endl;

  // CTRL+C and kill call triggers the trap sighandler()
  signal (SIGINT, sighandler);
  signal (SIGTERM, sighandler);
  cout << "Press CTRL+C to stop... " << endl;

  try {
    cout << "opening " << jsonfile << "..." << endl;
    router.setConfig (jsonfile, "modbuspp-router");

    if (router.debug()) {
      // if debug, list masters and slaves
      cout << endl;
      for (const auto & m : router.masters()) {

        auto master = m.second;
        cout << "Master " << m.first << " connected through " << flush;
        cout << master->connection() << ":" ;
        cout << master->settings() << " with the slaves below:" << endl;
        for (const auto & s : router.slaves()) {

          auto slave = s.second;
          if (slave->device() == master.get()) {
            cout << "> id: " << slave->number() << endl;
          }
        }
        cout << endl;
      }
    }

    if (router.open ()) { // open a connection
      cout << "Listening server on " <<
           router.connection() << ":" << router.settings() << "..."
           << endl << endl;

      router.run();
      while (router.isOpen()) {

        // std::this_thread::yield();
        std::this_thread::sleep_for (std::chrono::milliseconds (200));
      }
    }
  }
  catch (std::exception & e) {

    cerr << "Error: " << e.what() << endl;
  }
  catch (...) {

    cerr << "Unattended exception !" << endl;
  }
  
  return EXIT_FAILURE;
}
/* ========================================================================== */