1．Prodave 是用于pc 與s7 系列plc 之間的數(shù)據(jù)鏈接通信的工具箱。其實(shí)質(zhì)就是用戶(hù)通過(guò)調(diào)用“w95_s7.dll”等庫(kù)函數(shù)來(lái)解決 PLC 與PC之間的數(shù)據(jù)交換和數(shù)據(jù)處理問(wèn)題。 所需硬件為：CPU22x,PC/PPI編程電纜，帶COM口的PC。這可能是最簡(jiǎn)單的配置，很容易實(shí)現(xiàn)試驗(yàn)的目的。這里不需要安裝Prodave軟件，只要把“w95_s7.dll”文件拷貝到您程序相應(yīng)的目錄中去即可。2．通訊設(shè)置：打開(kāi)“控制面板”中“設(shè)置PG/PC接口”選項(xiàng)，在“應(yīng)用程序訪問(wèn)點(diǎn)”列表框內(nèi)選擇“S7ONLINE (STEP7) PC/PPI Cable”,在其屬性?xún)?nèi)的“超時(shí)”可以設(shè)置大點(diǎn)，這里設(shè)置為100ms，“波特率”設(shè)置為9.6kbps(因?yàn)槲业膒c/ppi電纜為國(guó)產(chǎn)的，不支持多主站)，“地址”為0。3。源代碼：①PLC程序：LD I0.0 MOVW 4766, VW0 ②VB程序： ****在模塊中聲明****： Public plcadr As plcadrtype Public gb_PlcConnected As Boolean Type plcadrtype adr As Byte ‘站地址，默認(rèn)值為2 SEGMENTID As Byte ‘段標(biāo)識(shí)符，固定值為0 SLOTNO As Byte ‘槽的編號(hào)，默認(rèn)值為2 RACKNO As Byte ‘機(jī)架號(hào)，固定為0 End Type Public Res As Long Declare Function load_tool Lib "w95_s7.dll" (ByVal nr As Byte, ByVal dev As String, adr As plcadrtype) As Long 。。。。。。。 ‘省略其它定義函數(shù)。 Declare Function as200_vs_field_read Lib "w95_s7.dll" (ByVal nr As Long, ByVal anz As Long, value As Byte) As Long ‘讀200PLC V存儲(chǔ)區(qū)的數(shù)據(jù)函數(shù) ****在窗體中聲明**** Private Sub Form_Load() Dim buffer(1) As Byte plcadr.adr = 2 plcadr.SEGMENTID = 0 plcadr.SLOTNO = 2 plcadr.RACKNO = 0 Res = load_tool(1, "S7ONLINE", plcadr) Res = as200_vs_field_read(0, 2, buffer(0)) If Res 0 Then MsgBox ("PLC連接錯(cuò)誤") gb_PlcConnected = False Else gb_PlcConnected = True MsgBox ("plc連接正確") Label1.Caption = buffer(0) * 256 + buffer(1) End If End Sub 通過(guò)以上程序可以正確讀出PLC中的數(shù)據(jù)。之后可以擴(kuò)展內(nèi)容，編寫(xiě)一個(gè)監(jiān)控軟件。