VB6.0+Winsock接收电文解密过程
首先在Client中定义结构体：
Public Type GaugeStatus
stx As Byte
MessageCode As Integer
DataType As Integer
StatusData(0 To 15) As Byte
etx As Byte
End Type
Public GaugeHeart As GaugeStatus
其中StatusData长度为16，它的取值规则如下：
First 16 bits are a copy of the gauge inputs
Bit 0 On pushbuttonBit 8 Spare
Bit 1 Off push buttonBit 9 Spare
Bit 2 Open Shutter push button Bit 10 S1 Gulmay error control
Bit 3 Close Shutter push button Bit 11 S2 Gulmay error control
Bit 4Operator E-stopBit 12 Junction box E-stop
Bit 5Go Forward push buttonBit 13 Forward limit
Bit 6 Go Reverse push buttonBit 14 spare
Bit 7 Console E-stopBit 15 Reverse limit
Second 16 bits are a copy of gauge inputs
Bit 0Shutter 1 openBit 8 Source 2 power OK
Bit 1Shutter 1 closedBit 9 Shutter 2 open
Bit 2spareBit 10 Shutter 2 closed
Bit 3Tube coolant flow 1Bit 11 Tube coolant flow 2
Bit 4spareBit 12 Source 1 coolant temperature
Bit 5Gate interlockBit 13 Source 2 coolant temperature
Bit 6Status Lamps OKBit 14 spare
Bit 7Source 1 power OKBit 15 spare
Third 16 bits are a copy of the gauge inputs
………………0-`5bit
Fourth 16 bits are miscellaneous gauge status
………………0-15bit
Bit encoding
Each 16 bits is stored in 4 (8 bit) bytes with one nibble of data ascii encoded per byte. Ascii encoding is done by OR’ing the value with 16#30. For example, to encode the 16 bits below
Bit 0Shutter 1 open1Bit 8Source 2 power OK1
Bit 1Shutter 1 closed0Bit 9Shutter 2 open1
Bit 2spare0 Bit 10 Shutter 2 closed0
Bit 3Tube coolant flow 11Bit 11 Tube coolant flow 21
Bit 4spare0 Bit 12 Source 1 coolant temperature 1
Bit 5Gate interlock0 Bit 13 Source 2 coolant temperature 1
Bit 6Status Lamps OK1Bit 14 spare0
Bit 7Source 1 power OK1Bit 15 spare0
The first nibble consists of bits 1001 and so will be encoded as 16#39
The second nibble consists of bits 1100 and so will be encoded as 16#3C
The third nibble consists of bits 1011 and so will be encoded as 16#3B
The fourth nibble consists of bits 0011 and so will be encoded as 16#33
那么根据编码规则，我应该怎么取值呢？
Private Sub WinsockSrv_DataArrival(Index As Integer, ByVal bytesTotal As Long)
Dim GetDataBuf() As Byte
WinsockCli(Index).GetData GetDataBuf, vbByte
Select Case bytesTotal
Case 22
‘这里我应该怎么取值呢？具体怎么编码呢？
End Sub
[解决办法]
设计进制转换和位运算.
[解决办法]
见:八进制与十六进制转二进制的方法
