什么是上位机_上位机软件介绍

什么是上位机
上位机是一台可以发出特定操控命令的计算机，通过操作预先设定好的命令，将命令传递给下位机，通过下位机来控制设备完成各项操作（应用最多的地方如：工业、水利、供电部门、交通等方面）。上位机都有特定的编程，有专门的开发系统，或以上是已经规定好任务，只能按特定的任务进行操作。简单说上位机就是命令的下达者，而下位机则是命令的执行者。

上位机软件介绍
下面介绍一种软件：物联网应用中收集感知节点信息,进行显示,控制的应用控制台。此软件主要有两部分组成,数据收发部分和显示部分
1、上位机在系统中的位置：处于网络层中，与嵌入式网关通过网线相连。实际应用时是放置在实验室的老师工作台上，供实验室的老师使用。
2、上位机的功能：此软件实时监视实验实中每个实验台的状况，包括上电或断电状态，实验台是否发出了警告，是否发出了求助信号，并对这些信号做出应答，还控制LED屏的文字显示。
3、上位机的设计实现： 此软件主要有两部分组成，数据收发部分和显示部分。数据收发指的是和嵌入式网关的数据收发。两者是通过网线连接的，所以应用的是TCP/IP 的Socket 套接字编程，嵌入式网关的设计中已经提到过，它在和上位机通信中是作为服务器的，那么上位机就是作为连接发起方。为了能保证网络连接的稳定性，我们把Socket读写的程序代码放在了try{} catch(){} 块中，一旦网络连接不正常，就会捕获到该异常，从而关闭程序。
4、关键代码如下：
private void ReadFromArm()
        {
            byte[] buffertocheck = new byte[1];
            int bytesize = 0;
            do
            {
                byte[] bufferofread = new byte[1024];
                try { bytesize = stream.Read(bufferofread, 0, bufferofread.Length); }
                catch (Exception ex) { connection = Indicator.Unconnected; MessageBox.Show("连接中断,程序将退出。");  Application.Exit(); read.Abort(); }
                //MessageBox.Show(BitConverter.ToString(bufferofread));
                byte[] buffertochecktemp = buffertocheck;
                buffertocheck = new byte[buffertochecktemp.Length + bytesize];
                Array.Copy(buffertochecktemp, 0, buffertocheck, 0, buffertochecktemp.Length);
                Array.Copy(bufferofread, 0, buffertocheck, buffertochecktemp.Length, bytesize);
                int index_1, index_2;
                while (Check7E(buffertocheck, out index_1, out index_2))
                {
                    byte[] buffertodecode = new byte[index_2 + 1 - index_1];
                    Array.Copy(buffertocheck, index_1, buffertodecode, 0, index_2 + 1 - index_1);
                    byte[] bufferofdecode = PPP.Decode(buffertodecode);
                    //MessageBox.Show(BitConverter.ToString(bufferofdecode));
                    if (bufferofdecode[0] == bufferofdecode.Length && CheckSum(bufferofdecode))//保证从ARM来的帧是正确的
                    {
                        byte[] Zuohao = new byte[2];
                        int subindex = 1, index = bufferofdecode[1]*256+bufferofdecode[2]-1;
                        string status=null;
                        switch (bufferofdecode[3])//分别处理从ARM来的帧
                        {

                            case POWER_ON://从ARM来的上电状态
                                status = "上电";
                                subindex = 1;
                                break;
                            case POWER_OFF://从ARM来的断电状态
                                status = "断电";
                                subindex = 1;
                                break;
                            case ABNORMAL://从ARM来的异常状态
                                status = "异常";
                                subindex = 1;
                                break;
                            case WARNING://从ARM来的警告信号
                                status = "有";
                                subindex = 2;
                                break;
                            case NEED_HELP://从ARM来的求救信号
                                status = "有";
                                subindex = 3;
                                break;
                        }
                        if (0 <= index && index <= 49)
                        {
                            listView1.Items[index].SubItems[subindex].Text = status;
                            if (status == "异常" || status == "有")
                                listView1.Items[index].SubItems[subindex].ForeColor = Color.Red;
                            else
                                listView1.Items[index].SubItems[subindex].ForeColor = Color.Black;
                        }
                    }
                    int newlength = buffertocheck.Length - 1 - index_2;
                    if (newlength == 0)
                    {
                        buffertocheck = new byte[1];
                    }
                    else
                    {
                        buffertochecktemp = buffertocheck;
                        buffertocheck = new byte[newlength];
                        Array.Copy(buffertochecktemp, index_2 + 1, buffertocheck, 0, newlength);
                    }
                }
            } while (connection == Indicator.Connected);
        }
        ///

        /// 向ARM发送
        ///

        /// 座号 2字节
        /// 命令字 1字节
        public void WriteToArm(byte[] Zuohao, byte mingling)
        {
            if (connection == Indicator.Connected)//在与ARM保持连接的情况下可写
            {
                byte[] frame = new byte[5];
                frame[0] = 0x05;
                Array.Copy(Zuohao, 0, frame, 1, 2);
                frame[3] = mingling;
                byte temp = 0;
                foreach (byte item in frame)
                    temp += item;
                frame[4] = (byte)(0 - temp);
                byte[] frametosend = PPP.Encode(frame);
                Console.WriteLine(BitConverter.ToString(frametosend));
                try { stream.Write(frametosend, 0, frametosend.Length); }
                catch (Exception ex) { }
            }
        }
        ///

        /// 向ARM发送
        ///

        /// 座号 2字节
        /// 命令字加ASC码 n字节
        public void WriteToArm(byte[] Zuohao, byte[] minglingandASC)
        {
            if (connection == Indicator.Connected)//在与ARM保持连接的情况下可写
            {
                byte[] frame = new byte[4+minglingandASC.Length];
                frame[0] = (byte)frame.Length;
                Array.Copy(Zuohao, 0, frame, 1, 2);
                Array.Copy(minglingandASC,0,frame,3,minglingandASC.Length);
                byte temp = 0;
                foreach (byte item in frame)
                    temp += item;
                frame[frame.Length-1] = (byte)(0 - temp);
                byte[] frametosend = PPP.Encode(frame);
                Console.WriteLine(BitConverter.ToString(frametosend));
                try { stream.Write(frametosend, 0, frametosend.Length); }
                catch (Exception ex) { }
            }
        }

另外数据收发还需要协议，和嵌入式网关通信的指令和协议定制如下：

因此数据量较少，协议也就比较简单，此协议在发送接收时用PPP封装。显示部分使用C#编写的运行于Windows .Net Framework 上的窗体应用程序，根据实际需求，对每个实验台状态的显示使用ListView控件实现，当出现异常情况，或实验台出现警告、求助信号时，ListView的相应字段文字会通过改变颜色来提醒监视人员，监视人员还可以通过一个文字发送窗体来向LED屏发送要显示的文字。总之界面清晰直观，简便易用。