M03 on rung 016 is on if the doorbell is pressed for a
second time on the fourth ring.
T05 on rung 019 is on if the doorbell is pressed
during either the third or fourth ring. It causes M02 or
M03 to stay latched on for 12 seconds, allowing adequate
time for the specialty rings.
T06, T07, and T08 produce different period pulses.
They are used together to produce complex identifiable
ring patterns when the doorbell is pressed on the third or
fourth ring.
The sound of the buzzer is modified on rungs 029
and 030 where the three pulses are mixed to produce the
more distinctive pattern.
The programming spreadsheet includes a record of all
the device settings determined during the design and
testing of the project.
Programmable relay systems are electrically simple but
operationally complex. The wiring is tested by the
observation of indicators on the front display.
The programming spreadsheet allows the designer to
organize the project, plus it provides valuable
documentation for the future when technicians have to
repair the system. NV
December 2015 35
FIGURE 14. Rungs 016 and 017.
FIGURE 15. Rungs 019 and 020.
FIGURE 16. Rungs 022, 024, and 026.
FIGURE 17. Rungs 028, 029, and 030.
FIGURE 18. Smart doorbell settings matrix.