Controllers
6.2 Drive functions
AT40, ATD400V, ATD400K, ATD4xxW, ATD400S, ATE250S, ATD400T
92
System Manual, 06/2016, A2B00096162-AN
6.2.43.7
Frequency analysis blocks
An input signal can be analyzed for specific frequencies and duty factors via the "FRQ"
frequency blocks. Two identical frequency analysis blocks are available, capable of detecting
frequencies of 1 Hz and 0.5 Hz with a duty factor of 20 %.
The detection criteria and the valid tolerances are described in detail in the following figure.
①
Input signal
②
Output signal
③
The output signal changes after 3 detected signal periods after the 4th edge
•
An input tolerance of (±) 40 ms is assumed.
•
Duty cycle: 20 % (17 to 23 %)
•
1 Hz frequency detection:
–
T = 1000 ms (±2 %)
–
t
on
= 200 ms
–
t
off
= 800 ms
–
Pulse/pulse ratio V = 25 %
•
0.5 Hz frequency detection:
–
T = 2000 ms (±2 %)
–
t
on
= 400 ms
–
t
off
= 1600 ms
–
Pulse/pulse ratio V = 25 %
Image 6-8
Frequency-based input signal detection
The outputs Q24 or Q26 become active when the analysis algorithm detects a frequency of
1 Hz with a 20 % duty factor in the input signal. The outputs Q25 or Q27 become active
when the analysis algorithm detects a frequency of 0.5 Hz with a 20 % duty factor in the
input signal.
The maximum response time at the output, i.e. the time after which the system can detect an
error or a deviation in the input signal frequency, corresponds to the period of the frequency
to be detected. Accordingly, a frequency of 1 Hz results in a maximum response time of 1 s
and a frequency of 0.5 Hz results in a maximum response time of 2 s.
6.2.43.8
On delay block
The "OnDELAY" block delays the input signal at the output Q28 by 2 s and at the output Q29
by 5 s.
