AS-Interface Power24

Power24 is an extension of the AS-Interface Specification which opens the possibility to reduce costs.  Power24 allows to run AS-Interface networks with a standard 24V DC power supply which normally is readily available and thus eliminates the special AS-Interface PSU. All products in this catalogue that are marked with the logo shown here are suited for use in Power24 networks.

In order to operate an AS-Interface Power24 network with a standard 24V DC Power Supply Unit as trouble free as a standard AS-Interface network the following conditions have to be met:

1. Power Supply Unit

The standard 24V DC Power Supply Unit has to comply with the following minimum requirements. These are:

  • The Power Supply Unit shall deliver a PELV voltage according to IEC60364-4-41 (PELV:  Protective extra low voltage).
  • The Power Supply Unit shall have a minimum DC voltage of 21,6V (24V -10%). Under no condition shall the voltage fall below. The maximum voltage may rise up to 30V.
  • The Power Supply Unit shall be capable to deliver a short term excess current of 0.4A above the nominal current during power up and during normal service.

Most modern 24V DC Power Supply Units meet these requirements.

2. Data Decoupling

For normal operation of an AS-Interface network a data decoupling circuit is required between the Power Supply Unit and the network. This data decoupling network is -- together with the Earth Fault Detection -- mounted in the small housing of our product  DW001 .

3. Master and Slaves

The Master and all Slaves as well as all other network components (such as repeater or earth fault detectors) have to be suited for service in AS-Interface Power24 networks. The manufacturer declares conformance with the Power24 Logo shown. 

4. Network

The network may be planned in free topology (tree structure) just like standard AS-Interface networks. There is one limit to be observed, however. The total network length is limited to max. 50m. This is due to the fact that the voltage drop along the line would otherwise rise to unpermissable values. The number of slaves that may be connected is not limited.