BECKHOFF EP20xx/EP28xx Output Module Installation and Debugging Guide

BECKHOFF EP20xx/EP28xx IP67 Digital Output Module Selection, Installation, and Troubleshooting Guide

Deploying I/O modules directly in harsh environments near machines in industrial automation sites can significantly reduce the size of control cabinets and wiring costs. The Beckhoff EP20xx/EP28xx series EtherCAT Box digital output module is an ideal choice for distributed I/O due to its high protection level of IP65/66/67, wide temperature operating range (-25~+60 ° C), and rich output current options (0.5A to 2.8A). However, when faced with a variety of models, the activation of diagnostic functions, safety behavior in the event of EtherCAT communication failure, and ATEX explosion-proof installation requirements, engineers often need a practical reference for the system. This article is based on official technical documents and presents a complete manual for model selection, mechanical installation, electrical wiring, TwinCAT configuration, and troubleshooting.

Product Series Overview and Selection Core

The EP20xx/EP28xx series includes multiple digital output modules, with the main differences being the number of output channels, single channel current, total current, connector type, and diagnostic function. When selecting, it is important to focus on the following dimensions:

Model Channel Number Single Channel Current Total Current Connector Diagnostic Function Special Instructions

EP2008-000x 8 0.5A 4A M8 (0001)/M12 (0002) Unbounded Type

EP2008-0022 8 0.5A 4A M12 (one per channel) without independent M12 socket

EP2028-000x 8 2.0A 4A M8 (0001)/M12 (0002) No high current output

EP2028-0032 8 2.8A 16A M12 (dual channel shared) without 7/8 "power connection, high total current

EP2038-000x 8 2.0A 4A M8 (0001)/M12 (0002) Short circuit/broken wire diagnostic type

EP2038-0042 8 2.4A 16A M12 (one per channel) Short circuit/disconnection/undervoltage M12 D-coded EtherCAT, 7/8 "power supply

EP2809-002x 16 0.5A 4A M8 (0021)/M12 (0022) without high-density 16 channels

EP2809-0042 16 0.5A 16A M12 (2 channels per socket) without high density, 7/8 "power supply

EP2816-0003 16 0.5A 4A ZS2001 Spring Terminal Short Circuit Detection IP20 Connector (Limited Protection Level)

EP2816-0004 16 0.5A 4A M16 19 pin short circuit detection IP67

EP2816-0008 16 0.5A 4A D-sub 25 pin short circuit detection IP67

EP2816-0010 16 0.5A 4A 2 × D-sub 9-pin short circuit detection IP67

EP2817-0008 24 0.5A 4A D-sub 25 pin short circuit/undervoltage 24 channel high-density

EP2839-0022 16 0.5A 4A M12 (2 channels per socket) Short circuit/disconnection/undervoltage M8 EtherCAT, diagnostic type

EP2839-0042 16 0.5A 16A M12 (2 channels per socket) Short circuit/disconnection/undervoltage M12 D-coded EtherCAT, 7/8 "power supply

Selection decision:

If diagnosis (short circuit, wire breakage detection) is required, priority should be given to the EP2038 and EP2839 series.

If driving high current loads (such as valve islands), choose EP2028-0032 (2.8A/channel) or EP2038-0042 (2.4A/channel).

If you need high channel density (16/24 channels), choose the EP2809, EP2816, EP2817, EP2839 series.

If compatibility with existing D-sub connector harnesses is required, choose EP2816-0008 or EP2817-0008.

Key points for mechanical installation and IP67 protection

2.1 Installation dimensions and fixation

Narrow body modules (30mm wide, such as EP2008, EP2028, EP2038, EP2816, EP2817) are fixed with two M3 bolts (mounting holes Ø 3.5mm).

The wide body module (60mm wide, such as EP2809, EP2028-0032, EP2038-0042, EP2839) is fixed with two M4 bolts (mounting holes Ø 4.5mm).

The bolt length should be greater than 15mm, and the installation hole should be non threaded. It should be matched with a nut or directly screwed into the threaded hole of the chassis.

It is recommended to use Beckhoff mounting rail ZS5300-0001 (stainless steel, preset M3 thread) to quickly install multiple modules.

2.2 Functional Grounding (FE)

For wide body modules (EPxxxx-002x, -0042), the fixing screws also serve as functional grounding (FE) connection points. Low impedance grounding connection must be used, such as installing the module on a grounded metal machine tool. Ensure that both screws are reliably grounded, otherwise it may affect EMC performance.

2.3 Implementation of IP67 protection

Key precautions:

All interfaces are pre installed with protective covers at the factory, but these covers are only for transportation protection and may not have been tightened. Before installation, it is necessary to confirm that all protective covers or cable connectors have been tightened to the specified torque (M8: 0.4Nm, M12: 0.6Nm, 7/8 ": 1.5Nm).

Unused interfaces must be sealed with suitable protective covers (ZS5000 series can be ordered).

IP67 protection level is only guaranteed when all interfaces are properly sealed.

2.4 ATEX explosion-proof installation (applicable to modules with ATEX certification)

For ATEX certified models such as EP2008 and EP2028, an additional protective cover BG2000-0000 or BG2000-0010 is required, and the ambient temperature is limited to 0-55 ° C (-25~+60 ° C for non ATEX). During installation, the cable needs to pass through the protective cover opening, and all interfaces of the module must be sealed. The protective cover itself also needs to be fixed. The transient overvoltage of the power supply voltage during use in explosion-proof areas shall not exceed 40% of the rated voltage.

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

Output is non-conductive (LED not lit), output is not enabled or Up power supply is missing. Check the Up voltage (24V) and GNDp connection; Confirm that the process data output bit is TRUE

The output light is on but the load does not operate. If the power supply is insufficient or the line voltage drop is too large, measure the voltage at the load end; Check the length and cross-sectional area of the cable; Calculate whether the total current exceeds the limit

Check the load connection if the output circuit of the diagnostic bit "Open load" is open or the load current is less than the detection threshold; For EP2038/2839, the threshold is approximately 1mA to ensure sufficient load current

The output terminal of the diagnostic bit "Short to 24V" accidentally contacts the 24V power supply. Check if there is a short circuit in the external wiring; If there is a false alarm, the diagnostic bit can be disabled

After communication interruption, the output did not close as expected. Safe state was not activated or the safety value was set incorrectly. Check the Safe state active and Safe state value settings in the CoE

After a short circuit, all outputs are turned off and cannot be restored. F800:01=False and Reset outputs have not been executed. Recovery is achieved by setting the process data "Reset outputs" (rising edge); Or change to TRUE to achieve automatic recovery

The total current of the module overheating alarm exceeds the rated value or the load current is reduced due to high ambient temperature; Strengthen heat dissipation; Check if it exceeds the upper limit of 60 ° C (ATEX is 55 ° C)

The installation of BG2000 protective cover in ATEX area has been rejected or the protective cover has been installed due to temperature exceeding; Ensure that the ambient temperature is between 0 and 55 ° C; all interfaces are sealed

LED Us/UP display red (EP2038-0042) undervoltage or auxiliary output overload check if the power supply voltage is less than 18V; check if the auxiliary output exceeds 0.5A

Maintenance and scrapping

Cleaning: Use only a vacuum cleaner or a slightly damp cloth to clean the casing. Do not use compressed air to prevent dust from entering the interior of the connector.

Sealing inspection: Regularly check the fastening status of all protective covers and cable joints to ensure IP67 protection.

Scrap: Dispose of according to the WEEE directive, the metal casing can be recycled, and the circuit board is disposed of as electronic waste.