Thread: serial port shutdown signal

You can just directly hook the +12V ACC line to the DSR, DCD, CTS, and then create a little software to shut down the computer if the DCD is low for 15 minutes. I have some VB code for shutting down, works with NT/2000 too:


Attribute VB_Name = "modShutdown"
'//*********************************//'
Private Const STANDARD_RIGHTS_REQUIRED = &HF0000
Private Const READ_CONTROL = &H20000
Private Const STANDARD_RIGHTS_READ = (READ_CONTROL)
Private Const STANDARD_RIGHTS_WRITE = (READ_CONTROL)
Private Const STANDARD_RIGHTS_EXECUTE = (READ_CONTROL)

Public Enum TokenRights
TOKEN_ASSIGN_PRIMARY = &H1
TOKEN_DUPLICATE = &H2
TOKEN_IMPERSONATE = &H4
TOKEN_QUERY = &H8
TOKEN_QUERY_SOURCE = &H10
TOKEN_ADJUST_PRIVILEGES = &H20
TOKEN_ADJUST_GROUPS = &H40
TOKEN_ADJUST_DEFAULT = &H80
TOKEN_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED Or TOKEN_ASSIGN_PRIMARY Or TOKEN_DUPLICATE Or TOKEN_IMPERSONATE Or TOKEN_QUERY Or TOKEN_QUERY_SOURCE Or TOKEN_ADJUST_PRIVILEGES Or TOKEN_ADJUST_GROUPS Or TOKEN_ADJUST_DEFAULT)
TOKEN_READ = (STANDARD_RIGHTS_READ Or TOKEN_QUERY)
TOKEN_WRITE = (STANDARD_RIGHTS_WRITE Or TOKEN_ADJUST_PRIVILEGES Or TOKEN_ADJUST_GROUPS Or TOKEN_ADJUST_DEFAULT)
TOKEN_EXECUTE = (STANDARD_RIGHTS_EXECUTE)
End Enum

Public Enum PrivilegeAttributes
SE_PRIVILEGE_ENABLED_BY_DEFAULT = &H1
SE_PRIVILEGE_ENABLED = &H2
SE_PRIVILEGE_USED_FOR_ACCESS = &H80000000
End Enum

Public Enum ExitOptions
EWX_LOGOFF = 0
EWX_SHUTDOWN = 1
EWX_REBOOT = 2
EWX_FORCE = 4
End Enum

Public Enum TokenAccess
TokenUser = 1
TokenGroups = 2
TokenPrivileges = 3
TokenOwner = 4
TokenPrimaryGroup = 5
TokenDefaultDacl = 6
TokenType = 8
TokenImpersonationLevel = 9
TokenStatistics = 10
End Enum

Type LUID
lowPart As Long
HighPart As Long
End Type

Type LUID_AND_ATTRIBUTES
pLuid As LUID
Attributes As PrivilegeAttributes
End Type

Type PTOKEN_PRIVILEGES
PrivilegeCount As Long
Privileges(0) As LUID_AND_ATTRIBUTES
End Type

Private Declare Function GetCurrentProcess Lib "kernel32" () As Long
Private Declare Function OpenProcessToken Lib "advapi32" (ByVal ProcessHandle As Long, ByVal DesiredAccess As TokenRights, ByRef TokenHandle As Long) As Long
Private Declare Function LookupPrivilegeValueA Lib "advapi32" (ByVal lpSystemName As String, ByVal lpName As String, ByRef lpLuid As LUID) As Long
Private Declare Function AdjustTokenPrivileges Lib "advapi32" (ByVal TokenHandle As Long, ByVal DisableAllPrivileges As Long, ByRef NewState As PTOKEN_PRIVILEGES, ByVal BufferLength As Long, ByRef PreviousState As Long, ByRef ReturnLenght As Long) As Long
Private Declare Function AdjustTokenPrivilegesOld Lib "advapi32" Alias "AdjustTokenPrivileges" (ByVal TokenHandle As Long, ByVal DisableAllPrivileges As Long, ByRef NewState As PTOKEN_PRIVILEGES, ByVal BufferLength As Long, ByRef PreviousState As PTOKEN_PRIVILEGES, ByRef ReturnLenght As Long) As Long
Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As ExitOptions, ByVal dwReserved As Long) As Long

Public Function Shutdown(Operation As ExitOptions) As Long

Dim lngProcess As Long
Dim lngReturn As Long
Dim lngToken As Long
Dim udtLUID As LUID
Dim lngTokenPrivileges As TokenRights
Dim udtTokenPrivNew As PTOKEN_PRIVILEGES

lngProcess = GetCurrentProcess()
lngTokenPrivileges = TOKEN_ADJUST_PRIVILEGES

lngReturn = OpenProcessToken(lngProcess, lngTokenPrivileges, lngToken)
lngReturn = LookupPrivilegeValueA(vbNullString, "SE_SHUTDOWN_NAME", udtLUID)

udtTokenPrivNew.PrivilegeCount = 1
udtTokenPrivNew.Privileges(0).Attributes = SE_PRIVILEGE_ENABLED
udtTokenPrivNew.Privileges(0).pLuid = udtLUID

lngReturn = AdjustTokenPrivileges(lngToken, 0, udtTokenPrivNew, 0&, 0, 0&)

Shutdown = ExitWindowsEx(Operation, 0)

End Function