Basics - Siemens LOGO! 8 Manual

2 Setup and description
2.3.1

Basics

Week timer
Every week timer has three setting cams via which you can parameterize a time
slot each. Via the cams, you can set the switch on and off times (see
If the output has not yet been set, the week timer will switch it on at a switch-on
time.
If a switch-off time is configured, the output of the week timer will be reset at the
switch-off time.
The switching state of the week timer depends on all three cams, No 1, No 2 and
No 3.
Figure 2-2: Week timer function block
Yearly timer
On certain dates, the yearly timer switches the output on or off.
The switch-on time indicates month and day, on which the timer is set.
The switch-off time indicates month and day, on which the timer is reset again.
(see Table
The function offers two repeat patterns:

Yearly:
Timer output switches on every year at the specified month and day of the
switch-on time and remains switched on until the specified month and day of
the switch-off time.

Every month:
Timer output switches on every month at the specified day of the switch-on
time and remains switched on until the specified day of the switch-off time.
The switch-on year specifies the first year in which the timer will be activated.
The switch-off year specifies the last year in which the timer will be switched off.
Figure 2-3: Yearly timer function block
Internal clock buffering
The internal clock of a LOGO! 8 is buffered by an accumulator and continues to run
in the event of a power supply failure.
The buffering time is influenced by the ambient temperature. At 25 °C (77 °F), it is
around 20 days.
Time Switch Function
Entry ID: 109745699, V1.0,
3-2).
04/2017
Table 3-1).
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