Basler Electric BE1-BPR - Manual (Page 114)

5-8 BE1-BPR BESTlogic Programmable Logic 9272000990 Rev J
Figure 5-2. Contact Input Logic Function Blocks
When a contact input changes state for the duration of the recognition time (r), then the input logic status
changes to the new state. The input logic status changes only if it does not match the contact input status
when the recognition timer expires. After being recognized (changing state), the contact input must stay in
a stable state for the defined debounce time (db) before another contact input state is recognized. If the
contact input status and input logic status match when the recognition timer expires, the debounce timer
is not started. The debounce timer delays further input logic status updates once the input logic status
changes for the duration of the debounce setting.
Recognition and debounce timer operation is illustrated in Figure 5-3 and summarized in the following
numbered paragraphs. The paragraph numbers correspond to the callouts in Figure 5-3.
Figure 5-3. Recognition and Debounce Timer Operation
(1) Recognition timer starts when the contact input changes state.
(2) Recognition timer restarts if the contact input changes state while the timer is running.
(3) If the contact input status and input logic status matches when the recognition timer expires, then
no action is required. (This occurrence is not illustrated in Figure 5-3.)
(4) If the contact input status and input logic status does not match when the recognition timer
expires, the input logic status is updated, and the debounce timer is started.
(5) Debounce timer restarts if the contact input changes state while the timer is running.
(6) Go to (1) when the debounce timer expires.
Recognition and debounce values are read or programmed using the LI command.
1 1
r
setting
db
setting
Contact
Input
Status
Recognition
Timer
Debounce
Timer
Input
Logic
Status
r r r
db db
2 2 4 6 4 6 4 5
= Recognition timer (r) restarted due to contact input state change
= Debounce timer (db) restarted due to contact input state change
D2861-13
09-15-99
db