ModbusRTU.h

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// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4; -*-
// vim: set shiftwidth=4 softtabstop=4 expandtab:
/*
 ********************************************************************
 ** NIDAS: NCAR In-situ Data Acquistion Software
 **
 ** 2021, Copyright University Corporation for Atmospheric Research
 **
 ** This program is free software; you can redistribute it and/or modify
 ** it under the terms of the GNU General Public License as published by
 ** the Free Software Foundation; either version 2 of the License, or
 ** (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU General Public License for more details.
 **
 ** The LICENSE.txt file accompanying this software contains
 ** a copy of the GNU General Public License. If it is not found,
 ** write to the Free Software Foundation, Inc.,
 ** 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 **
 ********************************************************************
*/
 
 
#ifndef NIDIS_DYNLD_MODBUSRTU_H
#define NIDIS_DYNLD_MODBUSRTU_H
 
#include <nidas/Config.h>
 
#ifdef HAVE_LIBMODBUS
#include <modbus/modbus.h>
#endif
 
#include <unistd.h>     // pipe
 
#include <nidas/core/SerialSensor.h>
#include <nidas/util/Thread.h>
 
namespace nidas { namespace dynld {
 
    using namespace nidas::core;
 
class ModbusRTU: public SerialSensor
{
public:
 
    ModbusRTU();
 
    void validate();
 
    void init();
 
    void open(int flags);
 
#ifdef HAVE_LIBMODBUS
 
    void close();
 
    IODevice* buildIODevice();
 
    SampleScanner* buildSampleScanner();
 
#endif
 
    bool process(const Sample* samp,std::list<const Sample*>& results)
        throw();
 
 
protected:
    class ModbusMessageStreamScanner: public MessageStreamScanner
    {
    public:
        ModbusMessageStreamScanner(): MessageStreamScanner(),
             _nbytesDiscarded(3)
        {
        }
        Sample* nextSampleSepBOM(DSMSensor* sensor);
 
    private:
        int _nbytesDiscarded;
    };
        
#ifdef HAVE_LIBMODBUS
 
    modbus_t* _modbusrtu;
 
    int _slaveID;
 
    int _regaddr;
 
    int _pipefds[2];
 
    class ModbusThread: public nidas::util::Thread
    {
    public:
        ModbusThread(const std::string& devname, modbus_t* mb, int regaddr,
                int nvars, int pipefd, float rate):
            Thread(devname+ "_modbus_thread", false), _devname(devname), _mb(mb), _regaddr(regaddr),
            _nvars(nvars), _pipefd(pipefd), _rate(rate)
        {}
        int run() throw();
    private:
        std::string _devname;
        modbus_t* _mb;
        int _regaddr;
        uint16_t _nvars;
        int _pipefd;
        float _rate;
 
        // no copying
        ModbusThread(const ModbusThread&);
        // no assignment
        ModbusThread& operator=(const ModbusThread&);
    };
 
    ModbusThread *_thread;
 
    class ModbusIODevice: public UnixIODevice {
    public:
        ModbusIODevice(): UnixIODevice() {}
        // pipe is opened by sensor open method.
        void open(int) {}
 
        void setFd(int val) { _fd = val; }
    };
 
    ModbusIODevice *_iodevice;
 
#endif
 
    uint16_t _nvars;
 
    SampleTag* _stag;
 
private:
    // no copying
    ModbusRTU(const ModbusRTU&);
    // no assignment
    ModbusRTU& operator=(const ModbusRTU&);
};
 
}}  // namespace nidas namespace dynld
 
#endif