BECKHOFF EP20xx/EP28xx Output Module Installation and Debugging Guide

Electrical wiring and power planning

3.1 Supply voltage Us and Up

All modules have two power supplies:

Us (Control Voltage): Provides power for EtherCAT communication, processor logic, and is typically used for auxiliary outputs (if any). Both input/output ports use M8 4-pin (A code) or 7/8 "5-pin.

Up (peripheral voltage): Provides power for driving digital outputs. The load current of the output channel comes from Up.

Note: Some modules have internal isolation between GNDs and GNDp (such as EP2008-0022, EP2028-0032, EP2809, etc.), while others share ground (such as EP2008-0001). Please refer to their respective technical data for details. When multiple modules are connected in series for power supply, it is necessary to confirm that the total current does not exceed the rated value of the connector (maximum 4A for M8, maximum 16A for 7/8 ").

3.2 Definition of connector pins (typical)

M8 power supply (IN/OUT): Pin1=Us (brown), Pin2=Up (white), Pin3=GNDs (blue), Pin4=GNDp (black), FE (gray) - but different modules may be different, please strictly follow the corresponding document.

7/8 "Power supply: Pin1=GNDp, Pin2=Up, Pin3=GNDs, Pin4=Us, Pin5=FE (refer to the illustration in the document for details).

3.3 Output connector

M8 3-pin (EP2008-0001, EP2028-0001, EP2038-0001): Pin1=+24V Us (auxiliary output), Pin3=GND，Pin4=Output。

M12 5-pin (most M12 models): Pin1=+24V Us, Pin2=Output B (or auxiliary), Pin3=GND，Pin4=Output A，Pin5=FE。 Note that different models of Pin2/4 have different functions. For example, in EP2028-0032, Pin2 outputs from adjacent sockets, achieving dual output sharing.

3.4 D-sub connectors (EP2816/2817)

EP2816-0008 (25 pin D-sub): The first 8 channels are channels 1-8, the last 8 channels are channels 2-8, and there are also Us/GND power supply pins. Pay attention to signal allocation.

EP2817-0008 (25 pin D-sub): 24 outputs are distributed in 3 groups (8 per group), with staggered output order (odd and even outputs arranged separately). Please refer to the document pin table for details.

Important reminder: Before wiring, be sure to check the specific model's pin allocation diagram. Even if the interface type is the same for different models, the pin definitions may be different.

TwinCAT configuration and diagnostic function enabled

4.1 Basic Configuration

The EP2xxx series is scanned and added in TwinCAT like a standard EtherCAT slave, with process data including output control bits by default. For models with diagnostics (EP2038, EP2839, EP2816/2817), the default process data may not contain complete diagnostic information, and the "Full Diagnosis" mode needs to be selected through the "Predefined PDO Assignment" to activate the diagnostic bit.

4.2 Enable advanced diagnostics (EP2038-0042, EP2839-00x2)

At the factory, the open load and short to 24V detection functions are turned off by default. Each channel must be manually enabled through the CoE parameter:

8000:01 (Detect open wire in off state): Detect wire breakage when output is turned off.

8000:02 (Detect open wire in on state): Detect disconnection when output is turned on.

8000:03 (Detect short to 24V): Detect output short circuit to 24V.

Set the corresponding sub index to TRUE to enable it. Channel 2 corresponds to 8010, channel 3 corresponds to 8020, and so on (with an interval of 0x10).

4.3 Safe State Behavior in the Event of Communication Failure

When EtherCAT communication is interrupted (such as power failure of the main station or cable breakage), the module can automatically switch the output to the preset safe value.

EP2038-0042/EP2839-00x2: Activate/disable this feature through the CoE parameter 80n0:04 (Safe state active) (default activation), and set the output value to 80n0:05 (Safe state value) (default 0=off).

EP281x series (EP2816, EP2817): Control the safety status activation (default activation) and safety value (default 0) of each output through 8000:n (channel 1) and 8010:0n (channel 2), respectively.

If you want the output to remain in the last state when communication is interrupted, you can set Safe state active to False.

4.4 Short circuit behavior configuration (EP281x series)

Response of CoE object F800:01 (Disable shut off) when controlling short circuit:

False (default): If any channel is short circuited, all outputs will be turned off and manually restored through the process data "Reset outputs".

True: Only the faulty channel is turned off, and it automatically recovers after the short circuit is eliminated.

In addition, F800:11 (Switch off time) sets the retry interval after short circuit detection (default 1000ms), and the module will periodically attempt to restart to check if the short circuit has been eliminated.

4.5 Factory reset

Writing the hexadecimal value 0x64616F6C (ASCII "load") in CoE 1011:01 will reset all backup objects to factory state. If it is an older module, you can try replacing the value 0x6C6F6164.

Common Troubleshooting Ladder Table

Troubleshooting steps for possible causes of fault phenomena

The module cannot enter the OP state due to ESI version mismatch or PDO configuration error to update the ESI file; Check if the predefined PDO has selected an unsupported combination