Siemens simatic s7-400 FM 450-1 - Page 81

Modes, settings, parameters and commands
8.12 Initiating a process interrupt
Counter module FM 450-1
Manual, 02/2014, A5E03648739-02
81
Edge controlled opening and closing of the HW gate
The following figure shows the edge controlled opening and closing of the HW gate of
counter 1.
Figure 8-5 Edge controlled opening and closing of the HW gate of counter 1
With the edge controlled door function the HW gate of counter 1 is opened by a positive
edge on input 1I0. The door is closed by a positive edge on input 1I1.
If positive edges occur simultaneously on inputs 1I0 and 1I1 an open gate is closed or a
closed gate remains closed. If input 1I1 is set a positive edge on input 1I0 cannot open the
gate.
The same applies analogously to counter 2 (inputs 2I0 and 2I1).
Status of inputs 1I0 (2I0) and 1I1 (2I1)
The status of the inputs 1I0 (2I0) and 1I1 (2I1) are indicated by the green LEDs CH1 IN 0
(CH 2 IN 0) and CH 1 IN 1 (CH 2 IN 1) and, within the user program, in the STS_STA and
STS_STP bit of the DB of the FC°CNT_CTRL.
Gate status
The gate status is indicated in the STS_GATE bit within the user program.