Chapter 6. Service Request Function
294 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
6.9 SVC_REQ 8: Reset Watchdog Timer
Use SVC_REQ 8 to reset the watchdog timer during the scan.
Ordinarily, when the watchdog timer expires, the CPU goes to STOP-Halt mode without warning.
SVC_REQ 8 allows the timer to keep going during a time-consuming task (for example, while waiting
for a response from a communications line).
SVC_REQ 8 has no associated parameter block; however, you must specify a dummy parameter,
which SVC_REQ 8 will not use.
SVC_REQ 8 Example
In the LD example at right, power flow through enabling
output %Q0127 or input %I1476 or internal coil
%M00010 causes the watchdog timer to be reset.