8255842
級別: 探索解密
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關(guān)于VB的MSComm串口接收兩次,Time事件 10分 如下:(1)和(2)單獨(dú)用按鈕命令可以正常執(zhí)行..用Timer1執(zhí)行1和Timer2執(zhí)行2,收回來的數(shù)據(jù)就很亂..把(1)(2)都寫到Timer1下面下,收回來的數(shù)據(jù)也亂..是不是輸入輸出緩沖區(qū)兩個混亂 Private Sub Timer1_Timer() '時鐘事件,間隔設(shè)定Interval毫秒就執(zhí)行一次 (1)DIM SENTDATA AS STRING,,Dim getdata MSComm1.InBufferCount = 0 '清空接收緩沖區(qū) MSComm1.OutBufferCount = 0 '清空發(fā)送緩沖區(qū) MSComm1.Output = 讀取數(shù)據(jù)指令 Do DoEvents Loop Until MSComm1.InBufferCount >= 20 'PLC應(yīng)該返回8個字符 固定的4+2*N '一個起始符+一個寄存器(有兩個字節(jié))(每個字節(jié)=2字符)+一個結(jié)束符+兩個校驗(yàn)和 getdata = MSComm1.Input Text1.Text = getdata ''返回的低字節(jié)在前,高在后 (2)Dim sendat As String,,Dim getdat MSComm1.InBufferCount = 0 MSComm1.OutBufferCount = 0 MSComm1.Output =讀取數(shù)據(jù)指令 Do DoEvents Loop Until MSComm1.InBufferCount >= 8 getdat = MSComm1.Input Text4.Text = getdat ''返回的低字節(jié)在前,高在后 |
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