Remote Processing RPC-52 - Manual (Page 32)

WATCHDOG TIMER CHAPTER 11
Page 30
Figure 11-1 W5 Watchdog jumper
DESCRIPTION
The watchdog timer is used to reset the RPC -52 if the
progr am or CPU "cr ashes" . W hen jump er W 5 is
installed, the W DOG comma nd must be executed a t least
once ever y 1. 2 seconds to av oid a rese t. T he timeou t is
not adjustable.
The watchdog should not be used if using a RPBASIC-52
INP UT sta tement. Also, loops which do not end quic kly
or are of inde terminate dur ation should be avoided unless
a timer reset pulse is included. An example of an
indeterminate loop is one that waits for a port condition
to change.
The w atchdog is ena bled by jum pering W 5. T he timer is
reset by executing a WDOG command.
The watchdog timer is part of a voltage monitor, battery
backup controller, and r eset chip U16.
PROGRAM EXAMPLE
The follow ing progr am fr agmen t resets the tim er wh ile
the program is running.
5000 WDOG