Siemens simatic s7-400 FM 450-1, Руководство пользователя, Страница: 33 / 130

Wiring
4.4 Module status after power is switched on
Counter module FM 450-1
Manual, 02/2014, A5E03648739-02
33
Input filter for 24 V encoder signals
To suppress faults you can assign parameters to the input filters (RC elements) with a
uniform filtering time for the 24 V inputs A*, B* and N*. The following two input filters are
available for each counter:
Table 4- 2 Input filter for 24 V encoder signals
Features Input filter 1
(default setting) Input filter 2
Typical input delay 1 μs 15 μs
Maximum count frequency 200 kHz 20 kHz
Minimum pulse width of the count signals 2.5 μs 25 μs
Digital inputs
You can use the digital inputs 1I0 and 1I1 for the gate control of counter°1.
You can use the digital inputs 2I0 and 2I1 for the gate control of counter°2.
The gates can be operated both in the level-controlled and edge-controlled modes (see
chapter "Modes, settings, parameters and commands (Page 65)").
The 1I2 digital input is for setting counter 1 to the load value.
The 2I2 digital input is for setting counter 2 to the load value.
The digital inputs are operated with a 24 V nominal voltage.
The digital inputs are electrically isolated from bus and count inputs.
Input filters for digital inputs
To suppress faults you can assign parameters to the input filters (RC elements) with a
uniform filtering time for the digital inputs 1I0, 1I1 and 1I2 or 2I0, 2I1 and 2I2. The following
two input filters are available:
Table 4- 3 Input filters for digital inputs
Characteristics Input filter 1
(default setting) Input filter 2
Typical input delay 1 μs 15 μs
Maximum frequency of the input signals 200 kHz 20 kHz
Minimum pulse width of input signals 2.5 μs 25 μs