BECKHOFF EL31xx Series 16 Bit EtherCAT Analog Input Terminal Manual

For EL3111/3112/3121/3122: Connect terminal point 3 or 7 (GND_int) to an external low impedance potential (such as 0V or sensor common terminal) to center the CMP potential of all channels.

For EL3114/3124: GND_int connected to the 0   V power supply contact, ensure that the sensor reference potential of all channels is close to 0   V. Mixing high and low side measurements is strictly prohibited.

6.4 Measurement values with high noise or jumping

Possible reasons: electromagnetic interference; The filter is not turned on; Poor grounding.

Solution: Use shielded twisted pair cables and connect the shielding layer to the Shield terminal. Enable 50/60 Hz FIR filter (via x800:06 and x800:15). Ground the sensor power supply and terminal power supply together. For devices with severe interference (such as frequency converters), use an independent power supply to power the terminals.

6.5 Firmware/hardware revision number mismatch (blue/red entries displayed during scanning)

When TwinCAT scans the actual hardware, if the actual revision number is higher than the one in the configuration, it will be displayed in blue (usually compatible, but it needs to be confirmed that the new feature does not affect the original logic). If the actual revision number is lower than the one in the configuration, it will be displayed in red (possibly incompatible).

Principle: The revision number of the actual terminal used should be ≥ the revision number in the configuration.

Solution: Use "Copy Before" in the "Correction Dialog" to update the configuration to the actual revision number or replace it with matching hardware.

6.6 CoE parameter cannot be saved or EEPROM lifespan issue

Beckhoff terminal saves CoE changes to EEPROM (with a typical lifespan of 100000 write operations). If the program frequently modifies parameters (such as multiple times per second), it will exhaust its lifespan.

Solution: For parameters that require frequent changes, use the NoCoeStorage function (if supported by the firmware): write the code word 0x12345678 to the object 0xF008, and the changed CoE value will no longer be written to the EEPROM. This function fails after the device is restarted.

7. Key parameter configuration and calibration

7.1 User Scaling

By enabling 0x80n0:01, the gain 0x80n0:12 (Q16 fixed-point format, default 65536 corresponds to 1.0) and offset 0x80n0:11 (INT16) can linearly transform the measured values. Formula: YS=(YH × AS/2 ^ 16)+BS. The gain is limited within ± 0x7FFFF, exceeding it will trigger error 0x06090031/32.

7.2 Limit Monitoring (Limit 1/Limit 2)

Enabled by 0x80n0:07/08, the limit value is set by 0x80n0:13/14 (INT16, consistent with the process numerical representation). The status bits 0x60n0:03 and 0x60n0:05 are output in a 2-bit format. The logic of greater/less can be reversed using 0x80n0:0E (Swap limit bits).

7.3 User Calibration

Enabling through 0x80n0:0A, offset 0x80n0:17 and gain 0x80n0:18 (INT16, default 16384 corresponds to 1.0) can compensate for sensor or system errors. Starting from a specific firmware version (see document compatibility table), user calibration is password protected: write 0x12345678 to 0xF009 to activate protection (read-only), and write 0x11223344 to remove protection.

7.4 Factory reset

Find object 0x1011:01 in CoE Online, write value 0x64616F6C (ASCII "load"), and all BackUp objects will be reset to the delivery state. Partial old terminals require the use of substitute value 0x6C6F6164.

8. Firmware updates and ESI description files

8.1 Precautions for firmware update

Only using TwinCAT 3, the system is in Config/FreeRun mode, with a cycle time of ≥ 1ms.

It is necessary to ensure that EtherCAT communication has no CRC errors or frame loss.

During the update process, it is absolutely forbidden to power off or disconnect the network, otherwise the terminals may be permanently damaged.

Confirm that the new firmware is compatible with the hardware version before updating (refer to the compatibility table in the documentation). If using Bundle firmware (file name containing REV and SW) and entering password 1 in the download dialog box, the controller firmware (*. efw) and ESI description can be updated simultaneously.

8.2 ESI/EEPROM Update

Right click on the online terminal, select "EEPROM Update", and choose the new ESI file (XML). After the update, the terminal needs to be powered off and restarted to take effect. Attention: Some terminals (such as EL3174-0002) store production calibration data, and updating ESI may overwrite this data. Please consult Beckhoff support.

9. Maintenance suggestions

Suggested inspection period notes

The tightening of terminal wiring may cause spring terminals to loosen due to annual vibration

Ventilation openings should be cleaned every six months using a vacuum cleaner, and compressed air is prohibited

Parameter backup (startup list) saves the CoE configuration to the startup list after each modification, facilitating quick terminal replacement

Firmware version check: Visit the Beckhoff website every 2 years to obtain updates and fix known issues