Siemens FM 450-1 - Page 70

Opening and closing the SW gate
The following 󹪝gure shows the opening and closing of the SW gate of counter 1.
4
1
2 3 4
Counter status
Count pulses
SW_GATE
Bit set
Bit reset
Figure 8-6 Opening and closing the SW gate
The SW gate is opened and closed by setting and resetting the input parameter SW_GATE of the
FC CNT_CTRL.
The closed gate can be reopened by setting the input parameter SW_GATE again.
Status of the SW gate
The status of the SW gate is signalized on the STS_SW_G bit of the DB of the FC°CNT_CTRL.
Terminating the count with the gate stop function
In addition, you can terminate the counting process at any time using the gate stop function of
the relevant counter, irrespective of the signals applied or the status of the SW gate. For this
purpose you set the GATE_STP input parameter of the FC CNT_CTRL.
When you reset the GATE_STP parameter, you can only open the gate for the counter concerned
by means of a positive edge, either at input 1I0 or 2I0 (HW gate) or resetting the SW_GATE input
parameter (SW gate).
Hardware interrupt
Opening and closing of a HW or SW gate can be used to trigger a hardware interrupt (see section
"Initiating a process interrupt (Page 76)".)
Default setting
In the default setting all gates are open; the count pulses are counted.
Modes, settings, parameters and commands
8.10 Command: Open and close gate
Counter module FM 450-1
70 Equipment Manual, 03/2022, A5E03648739-AC