Curtis Instruments 1351 - VCL, Watchdog Timer and Faults

5 — VEHICLE CONTROL LANGUAGE (VCL)
pg. 81
Return to TOC Curtis Model 1351 – December 2018
VCL, Watchdog Timer and Faults
Using VCL code, watchdog timers can be setup to ensure that specic parts of the VCL code are
operating properly. e watchdog can be started, stopped and “kept alive” in up to ve separate places
in the code. A Watchdog fault action denition will allow the VCL designer to select what happens
when the active Watchdog times out.
 Set_Watchdog_Timeout() Sets the time-out in milliseconds for any one of
ve watchdog timers.
is function will set the time-out in milliseconds for any one of ve watchdog
timers available. When the function is called, the specic watchdog timer is cleared
and the time-out threshold is updated.
e watchdog must not be running when this function is called or the Watchdog
fault and fault actions will be activated. Aer the rst Kick_Watchdog() has
been called for a timer, the watchdog cannot be stopped or set to a new timeout.
is is to prevent faulty code from re-enabling the watchdog constantly and thus
subverting its function.
When a Watchdog timer runs out (not kicked in time) VCL will halt and the
appropriate Watchdog fault (1 through 5) will be called. e system will then
activate the particular fault actions dened by the VCL programmer.
 Set_Watchdog_Timeout(WD#, Time)
:
WD# One of the 5 watchdog timers, WD1 through WD5
Time e watchdog’s time threshold, 20 ms (min.) to 60
s (max.) 20 – 60000
: None
 :
BAD_ID WD# out of range
PARM_RANGE Parameter (Time) out of range