SNTP Registry Settings (Windows CE 5.0)
The SNTP registry settings are located under the HKEY_LOCAL_MACHINE\Services\Timesvc registry key. Upon system startup, services.exe uses the information located under this key to initialize the SNTP service.
After you have modified the registry settings for your SNTP service, it is not necessary that you reboot your device for the changes to take effect. To implement the changes in the registry without rebooting the device, you must pass in the IOCTL_SERVICE_REFRESH IOCTL to the xxx_IOControl (Services.exe) function. This is described in the Configuring the SNTP Service topic.
The following table shows the named values for the HKEY_LOCAL_MACHINE\Services\Timesvc registry key.
| Value : type | Description |
|---|---|
| Context : REG_DWORD | Default set to zero (0). Specifies the initial value passed into the initialization routine.
|
| Dll : REG_SZ | Default set to "timesvc.dll". Specifies the name of the dynamic-link library (DLL) file to be loaded.
|
| Order : REG_DWORD | Default set to 99. Specifies the order in which Services.exe will load the service. |
| Keep : REG_DWORD | Default set to 1. If set to zero (0), the DLL will be unloaded immediately after initialization. |
| Prefix : REG_SZ | Default set to NTP. Specifies the prefix of the DLL to be loaded.
|
| Index : REG_SZ | Default set to zero (0). Specifies the service index.
|
| Server | Specifies the domain name of the SNTP server. If the name of one server is specified, this value is type REG_SZ. If a list of servers is specified, this value is type REG_MULTI_SZ. If no name is provided, server-only operation will be assumed.
|
| Refresh : REG_DWORD | Specifies the period, in milliseconds, between synchronizations with the SNTP server. This is ignored in server-only mode. |
| RecoveryRefresh : REG_DWORD | Specifies the time, in milliseconds, until next synchronization if the previous attempt failed. This is ignored in server-only mode.
|
| Threshold : REG_DWORD | Specifies the interval, in milliseconds, between the time on the SNTP server and the current time. If the difference between the SNTP server time and the local system time is larger, the update is ignored unless the system clock is presumed incorrect. This is ignored in server-only mode. |
| ServerRole : REG_DWORD | Default set to zero (0). Specifies the time server role. If this value is set to 1, a time server running on the Windows CE-based device will be enabled. |
| Trustlocalclock : REG_DWORD | Default set to 1. If this value is set to zero (0), the system is presumed not to have Real-time Communication (RTC) capabilities. If this is the case, server multicast is disabled until the clock synchronization with the SNTP server succeeds, and queries to the server return the "unreliable clock" flag. Also, time synchronization is forced on system wake-up.
If the client is disabled, the clock is presumed to be trusted and this value is ignored. |
| Multicast : REG_DWORD | Specifies the IPv4 address for multicast mode. Setting this value to 1 turns on the multicast server. |
| Multicastperiod : REG_DWORD | Specifies the interval between subsequent multicasts. |
| AutoUpdate : REG_DWORD | If 1, enables automatic time updates by SNTP client. "Server" must be specified. |
Ports
Both SNTP and NTP are clients of the User Datagram Protocol (UDP). The UDP port number assigned to NTP is 123.
See Also
Simple Network Time Protocol (SNTP) Overview | Configuring the SNTP Service | xxx_IOControl (Services.exe)
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