GPS Intermediate Driver GPS Hardware Registry Settings
The GPS Intermediate Driver uses the registry to determine how to connect to physical GPS hardware.
The GPS Intermediate Driver uses the settings in this topic when the InterfaceType registry entry is "COMM". For more information about the InterfaceType registry entry, see GPS Intermediate Driver Input Source Registry Settings.
Like the InterfaceType registry entry, these entries exist in a key named for the specific input source, beneath the HKEY_LOCAL_MACHINE\System\CurrentControlSet\GPS Intermediate Driver\Drivers key. For example, an input source that uses GPS hardware accessible at a specific COM port might have registry settings at the HKEY_LOCAL_MACHINE\System\CurrentControlSet\GPS Intermediate Driver\Drivers\AcmeGPSHardware key.
Note On some target devices, the root GPS Intermediate Driver registry key, and all subkeys, are protected. On these target devices,normalapplications can read but cannot write GPS Intermediate Driver settings.
The following table shows the registry entry that specifies GPS hardware connection information.
| Value : type | Description |
|---|---|
| CommPort : REG_SZ | No default setting.
Name of the COM port to which the physical GPS hardware is connected. For example, "COM1:". |
During initialization, the GPS Intermediate Driver calls the SetupComm function. The following table shows the registry entries from which the GPS Intermediate Driver retrieves parameters for the call to SetupComm.
| Value : type | Description |
|---|---|
| InputBufferSize : REG_SZ | Default setting is 4096 bytes.
Size, in bytes, of the physical GPS hardware's input buffer. |
| OutputBufferSize : REG_SZ | Default setting is 4096 bytes.
Size, in bytes, of the physical GPS hardware's output buffer. |
During initialization, the GPS Intermediate Driver calls the SetCommState function. The following table shows the registry entries from which the GPS Intermediate Driver retrieves parameters for the call to SetCommState. For additional information about these settings, see DCB.
| Value : type | Description |
|---|---|
| Baud : REG_DWORD | Default setting is 4800 baud.
Baud rate at which the GPS hardware operates. |
| ByteSize : REG_DWORD | Default setting is 8 bytes.
Number of bits in the bytes transmitted or received. |
| Parity : REG_DWORD | Default setting is 0 (NOPARITY, defined in DCB).
Parity scheme. Can be EVENPARITY, MARKPARITY, NOPARITY, ODDPARITY, or SPACEPARITY. |
| StopBits : REG_DWORD | Default setting is 0 (ONESTOPBIT, defined in DCB).
Number of stop bits. Can be ONESTOPBIT, ONE5STOPBITS, or TWOSTOPBITS. |
| fInX : REG_DWORD | Default setting is FALSE.
Whether XON/XOFF flow control is used during reception. |
| fOutX : REG_DWORD | Default setting is FALSE.
Whether XON/XOFF flow control is used during transmission. |
| fOutxDsrFlow : REG_DWORD | Default setting is FALSE.
Whether the DSR (data-set-ready) signal is monitored for output flow control. If this value is TRUE and DSR is turned off, output is suspended until DSR is sent again. |
| fOutxCtsFlow : REG_DWORD | Default setting is FALSE.
Whether the CTS (clear-to-send) signal is monitored for output flow control. If this value is TRUE and CTS is turned off, output is suspended until CTS is sent again. |
| fDtrControl : REG_DWORD | Default setting is 0x01 (DTR_CONTROL_ENABLE, defined in DCB).
DTR (data-terminal-ready) flow control. Can be DTR_CONTROL_DISABLE, DTR_CONTROL_ENABLE, or DTR_CONTROL_HANDSHAKE. |
| fRtsControl : REG_DWORD | Default setting is 0x01 (DTR_CONTROL_ENABLE, defined in DCB).
RTS (request-to-send) flow control. Can be RTS_CONTROL_DISABLE, RTS_CONTROL_ENABLE, RTS_CONTROL_HANDSHAKE, or RTS_CONTROL_TOGGLE. |
| fBinary : REG_DWORD | Default setting is TRUE.
Whether binary mode is enabled. This value must be TRUE. |
| fParity : REG_DWORD | Default setting is FALSE.
Whether parity checking is enabled. If TRUE, parity checking is performed and errors are reported. |
During initialization, the GPS Intermediate Driver calls the SetCommTimeouts function. The following table shows the registry entries from which the GPS Intermediate Driver retrieves parameters for the call to SetCommTimeouts. For additional information about these settings, see COMMTIMEOUTS.
| Value : type | Description |
|---|---|
| ReadIntervalTimeout : REG_DWORD | Default setting is 50 milliseconds.
Maximum acceptable time, in milliseconds, that can elapse between the arrival of two bytes. If this period of time is exceeded, the ReadFile operation is completed and buffered data is returned. |
| ReadTotalTimeoutMultiplier : REG_DWORD | Default setting is 0 milliseconds.
Multiplier, in milliseconds, used to calculate the total timeout period for read operations. For each read operation, this value is multiplied by the requested number of bytes to be read. |
| ReadTotalTimeoutConstant : REG_DWORD | Default setting is 500 milliseconds.
Constant, in milliseconds, used to calculate the total timeout period for read operations. For each read operation, this value is added to the product of the ReadTotalTimeoutMultiplier entry and the requested number of bytes. |
| WriteTotalTimeoutMultiplier : REG_DWORD | Default setting is 0 milliseconds.
Multiplier, in milliseconds, used to calculate the total timeout period for write operations. For each write operation, this value is multiplied by the number of bytes to be written. |
| WriteTotalTimeoutConstant : REG_DWORD | Default setting is 1000 milliseconds.
For each write operation, this value is added to the product of the WriteTotalTimeoutMultiplier entry and the number of bytes to be written. |
See Also
GPS Intermediate Driver Registry Settings | GPS Intermediate Driver Input Source Registry Settings
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