IE2311 by Beckhoff

The IE2311 is an I/O extension box manufactured by Beckhoff within the IE Extension Box Units series. Installed close to sensors and actuators, it provides eight digital channels that reduce cabinet wiring and transmit field-level signals to a controller over a single network connection. Its compact housing supports distributed automation in confined mounting areas, while pluggable M8 connections simplify installation and routine maintenance.

The module provides 4 inputs and 4 outputs, and each input draws 6 mA. Input signals pass through a 0.2 ms filter that complies with the EN 61131-2 Type 2 standard. The output drivers supply up to 0.5 A per channel at a rated load voltage of 24 VDC, allowing direct connection to small solenoids or indicator lamps. The inputs use the same 24 V logic level and include reverse-polarity protection to prevent damage from incorrect wiring. Signal connections use screw-in M8 connectors, while a dedicated four-pin M8 socket supplies power to the module and connected sensors. The channels are protected against short circuits, and internal current limiting helps protect the module and upstream wiring during electrical faults.

A four-pin M8 downstream port allows additional extension boxes to be connected in a daisy-chain topology without separate network hubs. The process image occupies 4 input bits and 4 output bits, allowing the controller to exchange cyclic data with minimal communication overhead. Channel sourcing is limited to 20 mA per channel, which controls the load placed on the associated supply circuit. An internal trip circuit caps fault current at a 1.5 A threshold and allows normal operation to resume after a transient fault is cleared. Galvanic separation provides control and fieldbus isolation, reducing the transfer of electrical disturbances between the field connections and the communication electronics. The combination of protected outputs, isolated circuitry, and compact connections makes the unit suitable for decentralized sensor and actuator wiring in automated machinery.