Siemens FM 450-1 - Page 30

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 57)").
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 󹪝lters for digital inputs
To suppress faults you can assign parameters to the input 󹪝lters (RC elements) with a uniform
󹪝ltering time for the digital inputs 1I0, 1I1 and 1I2 or 2I0, 2I1 and 2I2. The following two input
󹪝lters are available:
Table 4-3 Input 󹪝lters for digital inputs
Characteristics Input 󹪝lter 1
(default setting)
Input 󹪝lter 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
Digital outputs
For the purpose of directly initiating control processes, the FM 450-1 has the digital outputs 1Q0
and 1Q1 (for counter 1) or 2Q0 and 2Q1 (for counter 2) that are supplied via the load voltage
2L+.
The digital inputs are potentially isolated from the S7-400 bus and count inputs.
The digital outputs are P switches and can carry a load current of 0.5 A. They are protected
against overload and short circuit.
Note
The direct connection of relays and cutouts can be executed without external wiring
The time-related behavior of the digital outputs depends on the parameter assignment and is
described in greater detail in the chapter "Setting: Behavior of the digital outputs (Page 65)".
2L+ /2M load voltage
To ensure the power supply of the digital outputs 1Q0 and 1Q1 or 2Q1 and 2Q2 you have to
connect a load voltage of 24 V to the module terminals 2L+ and 2M.
An integrated diode protects the module from reversing the polarity of the load voltage.
Wiring
4.2 Terminal assignment of the front connector
Counter module FM 450-1
30 Equipment Manual, 03/2022, A5E03648739-AC