Barnett Engineering Pro Talk ARU CV2 - Manual (Page 18)

Configuration using the PC 3-4
B1272M001 BARNETT ENGINEERING LTD. ProTalk Cv2
debounce times, use the seconds timer to avoid the inaccuracy introduced by the one
minute resolution.
Default Debounce time: 0.05 sec
A Digital input port can also be used to perform special functions in the Cv2. In the
Groups section, it can be selected for the Local Acknowledge function, and in the
Hardware section it can be set to operate as a Reset Input for a Totalizer.
Watchdog Input
A Watchdog timer is used to monitor periodic events and will produce an alarm if the
event does not occur within the programmed Watchdog interval. Each time an event
occurs at the input, the timer is reloaded with the programmed value. When the timer has
expired without a refresh event, the alarm is set. Refresh activities can be changes from
low to high, changes from high to low, or both.
Watchdog input types use two timers for their operation: the Debounce timer and the
Watchdog Interval timer. Refer to the preceding Digital input description for details on the
Debounce timer. Two Watchdog time ranges, seconds and minutes, are available. The
seconds range has a maximum value of 1638 seconds (27 minutes) with a resolution of
25 msec. For longer Watchdog times the minutes range should be used. When set to
minutes, the Watchdog timer has a maximum value of 65,535 minutes with a resolution of
one minute. For short Watchdog times, use the seconds timer to avoid the inaccuracy
introduced by the one minute resolution. When setting the two timers, take into
consideration the relationship between the two. The Debounce time can not be greater than
the Watchdog Interval; otherwise a constant alarm condition will occur.
Default Watchdog time: 10 min
Interval Input
Interval timers measure the time interval that an input is active, either how long it is high or
how long it is low. The input is conditioned by the Debounce timer which is described in
the Digital input section. When setting the Debounce timer, consider the anticipated
duration of the interval. Since the Cv2 registers a change only after the Debounce time,
long debounce settings will affect the accuracy of the measurement.
Totalizer Input
Totalizer inputs measure the number of times that an event has occurred at the input. The
event can be a high to low transition, a low to high transition, or both. Before the change is
considered valid, it is conditioned by the Debounce timer - described in the Digital input
section. Take into consideration the expected time period between events when setting the
Debounce timer.
The count in the totalizer can be reset by two methods: by sending the Reset Code entered
in the Points section, or by using the Reset Input selection in the Hardware setup.