本人正在做毕设……要求用PLC采集压力传感器值、再通过PLC传给VB！VB与数据库连接  把采集的数据保存在数据库中   并且显示出来       希望高手指点PLC与VB的通信问题！谢谢……

这个应该可以用串品读数据的,好像是common控件吧。不记得了，知道的别砸砖

就是串口通讯，自己做个协议，不算难，要实例继续！

[ 本帖最后由 W11400661 于 2010-5-12 22:13 编辑 ]

协议这些我不太懂……我想做的是实时采集数据和实时显示……VB里的通信是不是要定义一个数组啊   怎么样才能保证接收到第二个数据而不把第一个数据充掉？

With MSComm1

Select Case .CommEvent

'*******************接收到报警器数据****************************
Case comEvReceive

.RThreshold = 0 '关闭中断

Gcrc1 = 0: Gcrc2 = 0    '初始化CRC数值

RecData = .Input  '接受侦标志AA

ReciveData(0) = AscB(RecData) '转换

If ReciveData(0) <> &HAA Then .RThreshold = 6: Set RecData = Nothing: Exit Sub '错误退出

Call CRC(ReciveData(0)) 'CRC效验

RecData = .Input  '接受侦标志55

ReciveData(1) = AscB(RecData)

If ReciveData(1) <> &H55 Then .RThreshold = 6: Set RecData = Nothing: Exit Sub

Call CRC(ReciveData(1))

RecData = .Input    '目标地址即PC机地址00

ReciveData(2) = AscB(RecData)

If ReciveData(2) <> &H0 Then .RThreshold = 6: Set RecData = Nothing: Exit Sub

Call CRC(ReciveData(2))

RecData = .Input  '源地址即报警器地址

ReciveData(3) = AscB(RecData)

Call CRC(ReciveData(3))

If CDec(ReciveData(3)) > 16 Or CDec(ReciveData(3)) < 0 Then .RThreshold = 6: Set RecData = Nothing: Exit Sub

RecData = .Input    '数据长度

ReciveData(4) = AscB(RecData)

If CDec(ReciveData(4)) < 3 Then .RThreshold = 6: Set RecData = Nothing: Exit Sub

Call CRC(ReciveData(4))

RecData = .Input

ReciveData(5) = AscB(RecData) '命令字

Call CRC(ReciveData(5))


一个字符一个字符接收