c0330.frm

PLC应用举例

VERSION 5.00
Object = "{648A5603-2C6E-101B-82B6-000000000014}#1.1#0"; "MSCOMM32.OCX"
Begin VB.Form Form1 
   BackColor       =   &H00FFC0C0&
   Caption         =   "Form1"
   ClientHeight    =   3195
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4680
   LinkTopic       =   "Form1"
   ScaleHeight     =   3195
   ScaleWidth      =   4680
   StartUpPosition =   3  '窗口缺省
   Begin VB.PictureBox Picture1 
      AutoRedraw      =   -1  'True
      BackColor       =   &H00FF0000&
      DrawStyle       =   6  'Inside Solid
      DrawWidth       =   2
      Height          =   6000
      Left            =   480
      ScaleHeight     =   7841.587
      ScaleMode       =   0  'User
      ScaleWidth      =   10824.51
      TabIndex        =   3
      Top             =   840
      Width           =   10000
      Begin VB.Label Label1 
         BackColor       =   &H00FFFFC0&
         Caption         =   "Label1"
         ForeColor       =   &H00FF8080&
         Height          =   255
         Left            =   120
         TabIndex        =   4
         Top             =   120
         Width           =   9187
      End
   End
   Begin VB.TextBox Text1 
      Height          =   375
      Left            =   480
      TabIndex        =   2
      Text            =   "Text1"
      Top             =   240
      Width           =   10000
   End
   Begin VB.CommandButton Command2 
      BackColor       =   &H0080C0FF&
      Caption         =   "Command2"
      Height          =   900
      Left            =   6360
      Style           =   1  'Graphical
      TabIndex        =   1
      Top             =   7080
      Width           =   975
   End
   Begin VB.CommandButton Command1 
      BackColor       =   &H0080C0FF&
      Caption         =   "Command1"
      Height          =   900
      Left            =   4200
      Style           =   1  'Graphical
      TabIndex        =   0
      Top             =   7080
      Width           =   975
   End
   Begin MSCommLib.MSComm MSComm1 
      Left            =   1320
      Top             =   0
      _ExtentX        =   1005
      _ExtentY        =   1005
      _Version        =   393216
      CommPort        =   4
      DTREnable       =   -1  'True
      InputLen        =   4
      RTSEnable       =   -1  'True
      InputMode       =   1
   End
   Begin VB.Timer Timer1 
      Interval        =   100
      Left            =   480
      Top             =   120
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'声明模块级变量.
Dim x1, i, j As Double
Dim p1, p2 As Integer
Dim aa() As Byte

'初始化,确定显示屏(Picture1)尺寸,分度,标题.
Private Sub Form_Load()
'请屏
Cls
'设计显示屏横坐标(时间分度),纵坐标(温度分度),以及显示屏背景颜色.
Label1.BackColor = &HFFFFC0
Label1.ForeColor = &HFF8080
Label1.Caption = "横坐标：每格10秒   纵坐标：每格摄氏10度"
Picture1.BackColor = &HFFFFC0   'vbBlue
'设计显示屏画曲线的风格.
Picture1.AutoSize = True
'设计按钮标题.
Command1.Caption = "启动"
Command2.Caption = "停止"
'设计定时器(Timer1)的定时中断时间(1秒),并设定其无效.
Timer1.Enabled = False
Timer1.Interval = 1000
'为显示屏设计横坐标和纵坐标的分度线.
Picture1.ScaleMode = 0
Picture1.ScaleHeight = 2000
Picture1.ScaleWidth = 6000
For i = 0 To 6000 Step 100
Picture1.Line (i, 0)-(i, 2000), RGB(255, 255, 255) 'vbWhite
Next i
For j = 0 To 2000 Step 100
Picture1.Line (0, j)-(6000, j), RGB(255, 255, 255) 'vbWhite
Next j
'设定通讯口(COM1),通讯参数(波特率9600,无奇偶校验,8位数据位,1个停止位),输入缓冲区为4个字符.
MSComm1.CommPort = 1
MSComm1.Settings = "9600,n,8,1"
MSComm1.InputLen = 4
'设计运行窗体为最大化.
Form1.WindowState = 2
'关闭定通讯口.
If MSComm1.PortOpen = True Then MSComm1.PortOpen = False
End Sub

 '点击按钮1,启动定时接收和发送数据.
Private Sub Command1_Click()
x1 = 0
Timer1.Enabled = True
End Sub

 '点击按钮2,停止定时接收和发送数据.并退出程序.
Private Sub Command2_Click()
Timer1.Enabled = False
End Sub

'定时中断,处理PC机向PLC发送数据,接收PLC的响应的返回数据并绘制各PLC的温控曲线.
Private Sub Timer1_Timer()
'声明过程级随机变量(aa).
ReDim aa(3)
'接收出错转到 eee:
On Error GoTo eee
'打开定通讯口.
MSComm1.PortOpen = True
'中断一次时间X1加1秒.
x1 = x1 + 1
eee:
'PC机接收PLC数据(其中P1是实测温度值,P2是设定温度值).
Do While MSComm1.InBufferCount < 4
Loop
aa = MSComm1.Input
p1 = Int(aa(0) * 255 + aa(1) * 1)
p2 = Int(aa(2) * 255 + aa(3) * 1)
'绘制PLC的温度曲线,并输出温度值.
Picture1.PSet (x1 * 10, 2000 - 10 * p1), vbRed
Picture1.PSet (x1 * 10, 2000 - 10 * p2), vbBlue
Text1.Text = "实测温度：" & Str(p1) & "设定温度：" & Str(p2) & "运行时间：" & Str(x1) & "秒钟"
If x1 >= 6000 Then
Cls
x1 = 0
Else
End If
'关闭定通讯口.
MSComm1.PortOpen = False
End Sub