SIMATIC S7-1200 DCM 1271 Data decoupling module 3RK7271-1AA30-0AA0

Overview

With the aid of the S22.5 data decoupling module, the AS-Interface network can also be supplied with 24 V DC or 30 V DC from a standard power supply unit and the transmission of data and power can be realized along one cable.

The combination of data decoupling modules and standard power supply units is therefore a cost-efficient alternative to the service-proven AS-Interface power supply units.

The quality of the data signals and the reliable operation of the AS-i network are not negatively affected as the result.

Application

The AS-Interface data decoupling module is designed for AS-Interface networks with 30 V or 24 V supply (AS-Interface Power24V).

Operation of an AS-i network with the data decoupling module and a 30 V standard power supply unit is technically equivalent to the use of an AS-Interface power supply unit and offers the service-proven features of AS-Interface for all applications.

AS?Interface Power24V uses a 24 V power supply unit in conjunction with a data decoupling module and is particularly suitable for

• Compact machines using AS-Interface input/output modules
• Applications in the control cabinet for AS?Interface integration of SIRIUS 3RT2 contactors using 3RA27 function modules

When using the double data decoupling module or other data decoupling modules, several AS?Interface networks can be operated with a single power supply unit. This generates another costs benefit.

Note:

The power supply units must comply with the PELV (Protective Extra Low Voltage) or SELV (Safety Extra Low Voltage) standards, have a residual ripple of < 250 mVpp, and in the event of a fault must limit the output voltage to a maximum of 40 V. SITOP power supplies (see “24 V power supply units” → “SITOP power supply”) or PSN130S 30 V power supply units (see “30 V power supply units”) are recommended.

Note on AS?i Power24V:

The length of an AS-i Power24V network is restricted to 50 m in order to limit the voltage drop along the cable.

AS?i masters, AS?i slaves and the sensors and actuators supplied through the AS?i cable must be designed for the reduced voltage. Sensors and actuators for the standard voltage range of 10 to 30 V can be supplied with sufficient voltage.

Please also continue to observe the requirements specified in the section entitled “Extension of AS?i Power24V” for implementation of AS?i Power24V, see “AS?Interface → Introduction → AS?Interface Specification → Extension of AS?i Power24V”.