Interval Counter Input
4-7
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
4.4
Initializing the SM 335’s interval counter input
Parameter assignments
The interval counter on the SM 335 requires no parameters. The pulse input func-
tions independently of the parameters assigned to the remaining analog channels.
The pulse input, therefore, does not have to be parameterized. The external
counter can be retrospectively parameterized with a timeout.
Monitoring time
After the monitoring time has expired, the interval duration FFFFFF
H
is initialized.
This means that a failure can be detected early (not only after 8.3 seconds).
The monitoring time is calculated as follows:
Monitoring time
+
8.388
256
· Byte 13 of DS1 [unit seconds]
Special case: As a default, ’0’ equates to 8.388 seconds.
Examples:
•
Byte 13 (DS1)
=
1
→
monitoring time
=
0.032765625 seconds
•
Byte 13 (DS1)
=
2
→
monitoring time
=
0.016382812 seconds
