Function description
Operating Manual PSS u2 ES 16DI
1004551-EN-01
10
}
The module detects any signals that are present at the input for longer than the min-
imum signal time t
signal_min
.
t
signal_min
= t
filter
+ t
ProcIM
t
ProcIM
: Input processing time (see
Technical details [
23]
).
}
A signal is always detected and signalled to the head module's PII if it is present for
longer than the sum of the following times:
– Minimum signal time t
signal_min
– ST scan time
Pulse stretching:
The module stretches a 1-signal or 0-signal at the input terminals to the configured pulse
stretch time t
stretch.
If the signal is longer than the pulse stretch time, then it is not stretched
any further.
Signal requirements at the terminals:
The 0-signal and the subsequent 1-signal together must be present at the input for longer
than twice the configured pulse stretch time t
stretch
.
Initialise position
0-signal in the module
1-signal in the module
1-signal stretching
0-signal in the module
0-signal stretching
0-signal in the module
Waiting for 1-signal
1-signal in the module
Waiting for 0-signal
0-signal at the terminal
after pulse stretching has
elapsed
Pulse stretching active
0-signal at the terminal
1-signal at the terminal
1-signal at the terminal starts
pulse stretching
0-signal at the terminal
starts pulse stretching
1-signal at the terminal
after pulse stretching has
elapsed
1-signal at the terminal
after pulse stretching has
elapsed
0-signal at the terminal
after pulse stretching has
elapsed
Fig.: States for pulse stretching
