Digital inputs/outputs, 24 V DC

Up to four digital 24 VDC inputs are available. The function of these inputs depends on the configuration of SlotGroup 1.

Two of the inputs can also be used as digital 24 VDC outputs, with a current carrying capacity of 0.5 A per channel.

Digital inputs

The digital inputs acquire binary control signals from the process level. Typically, these are mechanical contacts such as normally closed contacts or normally open contacts, electronic sensors such as inductive proximity switches, optical sensors or other methods in order to generate a low/high signal in the sense of control technology.

The inputs are type 3 inputs in accordance with EN 61131-2. The minimum pulse duration depends on the set software filter (index 0x80n0:11).

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 … 3 mA typ.

Signal voltage "1 - HIGH"

11 V ... 30 V typ.

3 mA typ.

Digital inputs/outputs, 24 V DC 1:
Characteristic curve input 24 VDC type 3

Notice

Fast digital inputs – interference from interfering devices

Please note that the input wiring has very little filtering. It has been optimized for fast signal transmission from the input to the evaluation unit. In other words, rapid level changes/pulses in the µs range and/or high-frequency interference signals from devices (e.g. proportional valves, stepper motor or DC motor output stages) arrive at the evaluation unit almost unfiltered/unattenuated. These interferences can be incorrectly detected as a signal.

  • To suppress interference, an additional input filter can be parameterized.
  • Furthermore, EMC-compliant cabling and the use of separate power supply units for the terminal and the devices causing interference are recommended.

Digital outputs

The digital outputs switch binary 24 VDC control signals from the automation device to the actuators, electrically isolated from the process level. Typical applications include the switching of standard actuators such as contactors and valves.

The outputs are short-circuit proof and can be switched to a safe state in the event of a bus error (0x80n0:11 "Safe state behavior").

The signal state is indicated by LEDs.

Technical data

Digital 24 VDC outputs

Switching times

TON: typ. 300 µs / TOFF: typ. 300 µs

Output current per channel

0.5 A

Load type

Ohmic, inductive, lamp load

CAUTION

Watchdog settings

Please refer to section "Notes for setting the watchdog".