NI6509 Watchdog timer expires prematurely

Hello,

I am using the Watchdog functionality of NI6509 PCI board.

The problem I am experiencing is that Watchdog time sometime expires prematurely.

Especially if I stop the watch dog and restart it again.

Please see the attached NI6509Controller.cpp, where I am defining following functions:

1) SetupWatchDogTask 

2) StopBoardTask

3) RunWatchDogThread

Basically my thread is running the thread function RunWatchDogThread, waiting to receive following commands:

- WD_START, WD_PUMP, WD_STOP  and calls the functions as described in the code.

Usually I am starting the Watchdog with timeout = 5s and start pumping with command WD_PUMP.

At some time I am stopping it by sending WD_STOP command, 

By this point the functionality works fine.

Next time I start the Watchdog( WD_START with 5s ), it stops prematurely within a second.

Could you please help?

Thanks in forward,