Modbus ASCII LRC检验码VB6代码表示法

Dim Samplstr as string

Dim LRC as integer

Dim LRChex as string

Dim I as integer

Samplestr= "ABCD123REWFHG"

For I = 1 to len(Samplestr)

      LRC = (LRC + asc(Mid$(Samplestr,I,1))) and &HFF

Next I

LRC = (&HFF - LRC + 1)

LRChex = Hex$(LRC)

BTW:

Modbus ASCII 计算LRC时不包括引导符冒号和结束的换行回车符，即前面的 &H3A和后面的&H0D, &H0A不要参与计算。