75
LOGO! Manual
A5E00067781 01
Note
Always specify a time T
0.10 s. For T = 0.05 s and
T = 0.00 s the time T is not defined.
Accuracy of T
All electronic components have minute differences. This
can result in deviations in the set time (T). In LOGO! the
maximum deviation is 1 %.
Example:
In 1 hour (3600 seconds) the deviation is 1 % (i.e. 36 sec-
onds).
In 1 minute the deviation is therefore only 0.6 seconds.
Accuracy of the time switch
To make sure that this deviation doesn’t result in the clock
in C variants running inaccurately, the time switch is regu-
larly compared with a high-precision time base and ad-
justed accordingly.
This results in a maximum time error of
5s a day.
4.3.3 Clock Buffering
The internal clock of a LOGO! module continues to run if
there is a power failure, i.e. it has a power buffer. The dura-
tion of the reserve power is affected by the ambient tem-
perature. At an ambient temperature of 25
°
C the typical
power buffer is 80 hours.
4.3.4 Retentivity
The switching states and counter values can be kept reten-
tively in the special functions. To do this, retentivity must be
switched on for the relevant function.
LOGO! Functions
Summary of Contents for LOGO! 24
Page 216: ......
