Advantech TPC-870, User Manual

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TPC-870 User Manual 44
Appendix B Watchdog Timer on WinCE
There is a built-in Watchdog timer on Windows CE 5.0 for TPC-870. You
can access it through WIN32 API. TPC-870 provides a WDT driver to
allow users to enable/disable the Watchdog timer. The driver name is
“WDT1:”. Programmers must open this driver before using the resources.
Then programmers can use DeviceIOControl functions to enable/disable
Watchdog timer. The introduction below includes the DeviceIOControl, the
definition of the parameter and an example.
B.1 DeviceIOControl
This function sends a control code directly to a specified device driver,
causing the corresponding device to perform the specified operation.
BOOL DeviceIoControl(
HANDLE hDevice,
DWORD dwIoControlCode,
LPVOID lpInBuffer,
DWORD nInBufferSize,
LPVOID lpOutBuffer,
DWORD nOutBufferSize,
LPDWORD lpBytesReturned,
LPOVERLAPPED lpOverlapped );
Parameters:
hDevice
[in] Handle to the device that is to perform the operation. Call the Create-
File function to obtain a device handle.
dwIoControlCode
[in] Specifies the control code for the operation. This value identifies the
specific operation to be performed and the type of device on which the
operation is to be performed. No specific values are defined for the dwIo-
ControlCode parameter. However, the writer of a custom device driver can
define IOCTL_XXXX control codes, per the CTL_CODE macro. These