Combi i/o device

Combi IO devices are essential components of complex building automation. Find out here how to use the high-quality IO devices and what options there are for your installation. In any case, these devices increase the efficiency of your installation. Learn more about these modules and why it is so important for them to work properly.

What is an IO device?

An IO device - also known as an input-output module - enables communication between a computer system and a peripheral device. This type of processor communication between devices increases a computer's capabilities. The operating system is enabled to connect to the outside world. Communication and interaction takes place through sending and receiving information. Possible input information are, for example, signals from user inputs or binary inputs. Output signals are sent by the system or converted into actions as manipulated variables by actuators. With the use of a multifunctional input module, the work can be carried out more efficiently and accurately. Typical IO devices include:

KNX universal interfaces
KNX universal controller
KNX switching actuators with integrated binary inputs
KNX button interfaces with outputs for LED control
special KNX room controller with a variety of special functions

TIP:

An IO device can interface with a large number of bus protocols, for example PC Cards, USB, PCI, VMEbus and FireWire.

In this eibabo® category you will find, for example, KNX devices with multiple functions from top manufacturers such as ABB, Berker, Busch-Jaeger, Gira, Hager, Issendorf, Jung, Lingg & Janke, MDT, Merten, Siemens and Theben.

What are the most important functions of an IO device?

An IO device is an essential link in the control chain and closes the gap between your computer system and the external devices. It can perform multiple functions including:

Communication between the devices in the system

An IO device assumes several functions within the scope of device communication. This includes the transmission of status messages, the sending of commands and the transmission of information.

communication to the processor

Full communication with the processor includes recognizing its own IP address, decoding and accepting commands, and reporting status updates.

error management

An IO device detects different types of problems that can occur between the computer system and a peripheral device. These can be mechanical problems, such as a used printer cartridge or errors that occur during data transfer.

Source: eibabo®, ABB IO actuator 8-fold IO/S8.6.1.1 Image: ABB IO actuator 8-fold IO/S8.6.1.1

timing

In order to be able to correctly manage the flow of information between the system and the external device as part of time management, the IO device accesses the internal resources of a computer.

data buffering

One of the most important functions of an IO device is managing the transmission speed between memory, processor and other external devices.

How and where can IO devices be mounted?

There are many options for mounting IO devices and they depend on your existing installation. Choose from the following options:

Panel mounting - the unit is bolted to a chassis or attached to a panel
Rack mounting - the device fits into a standard housing, such as a 19-inch rack or similar
Installation on DIN rails - the device is attached to one of the common DIN rails or G-rails
free installation - the device has a stable housing and is set up in a freely selectable place
Printed circuit board assembly - the device plugs directly into computers or is attached to the case

What advantages do IO devices offer?

Depending on the IO device involved, each can play a significant role within an effective operating system. In a programmable logic controller (PLC) and other operating systems, these devices offer the following advantages:

a compact design saves space in almost any assembly environment
the installation can be done remotely
Hardware and associated costs can be saved
the wiring and cable setup is simple and clear

What are the properties of the inputs and outputs on the IO devices?

As a rule, IO devices offer digital channels, analog channels or a combination of both variants. The digital inputs and outputs handle low-level on-off signals. Analog inputs recognize signals such as current, voltage or frequency. Devices with combined channels often process the signals using analog-to-digital converters.

The input channels of a device are differentiated as single-ended (SE) or differential (DI). Single-ended inputs consist of two contacts, one of which carries a voltage. The other is connected to ground. Such installation is simpler and cheaper than differential signaling. However, the inductance of the signal line and the difference in ground voltage between the transmitter and receiver will cause noise interference. Differential communication uses two mutual signals on two paired contacts. The difference between the two signals represents the meaningful signal value. Common-mode rejection prevents noise interference. Differential inputs respond to the voltage difference between the two contacts. These are therefore suitable for low-voltage, long-distance and high-resolution applications. The type of input channels your device has can usually be found in the product description. For example, if you have a 16SE-8DI device, it offers 16 single-ended and 8 differential inputs.

isolation

Certain areas of the electrical system can be isolated from others. This avoids unwanted current flow or signal flow between the areas.

For isolation, please distinguish between channel-to-channel isolation, isolated analog input, isolated analog output, isolated digital input, and isolated digital output.