Debounce Timer

Input devices like a door sensor can generate multiple spurious events (such as Door Forced Open events) within a short span of time under the following conditions:

·         If the sensors are too sensitive to small movements of the door but the door does not open.

·         Have faulty wiring.

·         Are incorrectly installed.

·         Are subject to vibrations.

To prevent spurious events, a debounce timer can be used to mask events within a specified time interval. When the debounce timer is applied, a transition event is considered valid only if it does not change for at least debounce timer interval.

Note   The debounce timer applies only to events generated by input devices (sensors), such as INPUT_LOW/INPUT_HIGH. These events are not propagated to the ICPAM server, so there is no way of validating the debounce timer using Events Monitoring from the ICPAM server. Debounce timer validations can only be performed using the debugging logs on the controller for the sensor For example, see the bp_msg log.

The debounce timer is disabled by default (the default timer is zero seconds, meaning there is no event suppression). To enable the timer, configure each input interface with a maximum value of 500 milliseconds.

To determine the correct timer value, observe the events to ensure that valid events are not being suppressed. Valid events can be missed if the debounce timer value is too high. If valid events are suppressed, reduce the timer value.

Note   The debounce timer currently does not support tamper and power-fail devices.

Procedure

To configure the debounce timer, do the following:

Step 1            Create a new input device template.

a.  Select Doors > Templates > Device Templates. The Device Templates screen appears.

b. From the Device Templates screen, click the Add... button on the toolbar.

create_new_device_template00139.png

c.  Click to highlight a door sensor or a duress sensor.

d. Click Next. A screen with the debounce timer field on it.

e.  Specify the debounce timer value in the Debounce Timer (ms) field.

Step 2            Create a new input device for the gateway.

a.  Go to Doors -> Hardware Tree

b. Create a new input device for the gateway.

new_generic_input_device_selection_2.png

 

c.  Select the Properties tab.

d. Choose the corresponding device template.

e.  Enter the debounce timer value in the appropriate field.

07_templates_cpam00140.jpg

 

Tip           If the input device is already associated with the gateway, right-click the interface, select Edit and enter the debounce timer value. After setting the debounce timer the configuration must be applied on the associated gateway.

Note  The default value for the Debounce Timer is 0.

 

See also:

Configuring Door and Device Templates