Author Topic: Using the External Serial PC Watchdog as a timer only  (Read 3309 times)


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Using the External Serial PC Watchdog as a timer only
« on: November 02, 2010, 14:25:38 »
The External Serial PC Watchdog has been used by some customers for a timing device only with a relay closure.

The External Serial PC Watchdog has a Reset output available on a 1/8" (3.5mm) stereo jack. The two relay contacts are on the inner two contacts of the jack (Tip & Ring or Right & Left Channel). The sleeve of the jack is grounded through its connection to the case.  These dry contacts can switch a maximum of 24 volts and 250 mA. Do not exceed these ratings.

The External Serial device has non-volatile memory that allows you to modify both the Power On Delay (POD) and the watchdog time out values using the BPI_WDog_Config program (or the DLL). If you were to set the POD time to 30 seconds and the watchdog time to 30 seconds then you would have timer that would close the dry contact relay for a 3 second pulse once every 60 seconds.

The non-volatile POD and Watchdog time both allow values up to 65535 seconds for a total delay of up to 36.4 hours. The relay pulse time can also be set in 50mS tics up to a value of 255 or 12.75 seconds.

A good source for the plug to use with this jack is a Radio Shack PN: 274-869. Another option is to get a 1/8 (3.5mm) extension cable from Walmart, Best Buy, etc and cut off one end. Strip back the insulation and the shield and use the two inner conductors.
« Last Edit: June 19, 2011, 19:17:17 by Admin »