Latch and gate inputs

The terminal provides two digital 24 V DC inputs. The function of these inputs is described in the respective chapter.

Both inputs are type 3 inputs according to EN 61131-2, with a minimum pulse duration of tON > 1 µs.

Digital input type 3, according to EN 61131-2

Voltage [V]

Input current [mA]

Signal voltage “0 - LOW”

-3 V…+5 V typ.

0 mA…2.6 mA typ.

Signal voltage “1 - HIGH”

11 V…30 V typ.

2.5 mA typ.

Latch and gate inputs 1:
Fig.3: Characteristic curve input 24 V DC type 3

Notice

Be aware of bouncing when using electromechanical switches and push buttons

When using electromechanical switches and push buttons, repeated closing and opening of the switch or push button can occur when the switch or push button is actuated, which is referred to as bouncing.

  • If the function 0x80n0:22 “Enable continuous latch extern” or 0x80n0:23 “Enable continuous latch extern 2” is active, the stored value will be overwritten several times due to bouncing. This returns not the first value, but the last value stored in the input process data “Latch value” (index 0x60n0:12) or “Latch value 2” (0x60n0:22).
  • If the function is deactivated, only the first opening or closing of the switch or push button is detected and saved as a value in the corresponding parameter. No other actions are taken into account.