Private/Add-HexStreamEncapsulation.ps1
|
Function Add-HexStreamEncapsulation { Param($iO) foreach ($row in $iO) { Write-Verbose ("[MsgBuilder]: Processing command encapsulation: [" + $iO.Command + "]") # requires $global:BMSInstructionSet defined #assemble header #message is the entire message to be sent, including Start, End, checksums, etc. #instruction is just the instrction portion of the message. #Instance array for hexstream $HexStream = New-Object System.Collections.Generic.List[System.Object] #Clear instance of bytestream $ByteStream = $null #assemble the header, add to message. $HexStream.Add($BMSInstructionSet.Config.Message.Components.STX.ToLower()) $HexStream.Add($BMSInstructionSet.Config.Message.Components.DST.ToLower()) $HexStream.Add($BMSInstructionSet.Config.Message.Components.SND.ToLower()) Write-Verbose ("[MsgBuilder]:" + ($HexStream -join "") + " Header (STX)(DST)(SND) appended") #count length of all cmd:data bytes in payload, add to message. $ByteCount = "{0:x2}" -f [int16]($Row.Hex.Count) $HexStream.Add($ByteCount) Write-Verbose ("[MsgBuilder]:" + ($ByteCount -join "") + " Instruction byte count appended") #add payload bytes to hexstream from instruction object row $Row.Hex | %{$HexStream.Add($_)} Write-Verbose ("[MsgBuilder]:" + ($Row.Hex -join "") + " Instructions appended") #compute/add CRC #CRC-16 is calculated [in these bytes] <STX>[<DST><SND><LEN><MSG>[<QRY>]]<CRC><CRC><ETX> $CRC = (Get-CRC16 -HexData ($HexStream[1..($HexStream.count)] -Join "")) -replace '..', "$& " -split " " #add crc bytes ForEach ($HexByte in $CRC[0..1]) { $HexStream.Add($HexByte) } Write-Verbose ("[MsgBuilder]:" + $CRC + "Bytes appended") #add end transmission $HexStream.Add($BMSInstructionSet.Config.Message.Components.ETX.ToLower()) Write-Verbose ("[MsgBuilder]:" + (($BMSInstructionSet.Config.Message.Components.ETX.ToLower() -join "")) + " Footer assembled (ETX)") Write-Verbose ("[MsgBuilder]: Assembly complete") $ByteStream = $HexStream | %{[convert]::ToByte($_,16)} $ByteStreamSend = (@{ "RawStream"=$ByteStream; "InspectedStream"=($ByteStream | Format-Hex -Encoding ascii) }) $Row | Add-Member -Name "ByteStreamSend" -Type NoteProperty -Value $ByteStreamSend } return $iO } |