Beckhoff EL31xx Series 16 Bit EtherCAT Analog Input Terminal Manual

Beckhoff EL31xx Series 16 Bit EtherCAT Analog Input Terminal Manual

Full range product classification and core parameters

The EL31xx series is a 16 bit signed ADC with unified basic hardware specifications: appearance 15 × 100 × 70mm (installation width 12mm), protection IP20, E-Bus power supply, 500V electrical isolation (bus side and field side); Supports distributed clock DC (accuracy<1 μ s), with sampling speed much higher than EL30xx, and input filter default cutoff frequency of 5kHz. Divided into seven sub series based on signal type, wiring method, and function, including standard, enhanced, and safety versions.

1. Summary of functions and key parameters of each sub model

(1) EL310x: ± 10V differential voltage input

Model: EL3101 (1-channel), EL3102 (2-channel), EL3104 (4-channel)

Signal range: -10 V~+10 V, input impedance>200k Ω

Conversion time: about 40 μ m for a single channel, about 60 μ m for two channels (40 μ m for high-speed mode), and about 100 μ m for four channels

Accuracy: 0~55 ℃ error ＜ ± 0.3% FS; Wide temperature (-25~60 ℃) ＜ ± 0.5% FS

Features: Differential input, strong anti-interference ability; There is no hardware error light, only a process word indicating the status.

(2) EL311x: Current differential input

Basic model EL3111/3112/3114: standard 0-20 mA differential;

Special EL3112-0011: -20~+20 mA bidirectional current differential;

Internal impedance: 85 Ω+diode; The maximum common mode voltage is 10V;

Each channel is equipped with an independent red ERROR fault light to detect overcurrent and undercurrent.

(3) EL312x: 4~20 mA differential current input

Model: EL3121 (1-channel), EL3122 (2-channel), EL3124 (4-channel);

Derivative EL3124-0090: Integrated TwinSA SC single channel safety function, can be used for safety circuits;

Signal: Industrial standard 4-20mA, supports wire breakage detection, hardware fault light+process word dual alarm;

The electrical and timing parameters are consistent with EL311x.

(4) EL314x: 0~20 mA single ended current input

Basic model EL3141/3142/3144:0~20mA single ended;

Special EL3142-0010: -10~+10 mA small range single ended;

Reference potential binding module internal 0V, compatible with three wire sensors.

(5) EL315x: 4~20 mA single ended current input

Model: EL3151/3152/3154, the most commonly used 4-20mA single ended in industry;

EL3154 has a built-in 24V output, which can directly supply power to two-wire transmitters without the need for external power supply;

Standard disconnection, over/under range detection, and visual warning of fault lights.

(6) EL316x: 0~10 V single ended voltage input

Model: EL3161/3162/3164, signal 0~10V single ended;

Input impedance>200k Ω, suitable for conventional voltage type sensors; There is no independent fault light, and the status is fed back through process words.

(7) EL3174 Multi functional Universal Terminal (Flagship)

4-channel configurable type, voltage/current mode software switching, available in multiple versions, supporting 107% range extension (compatible with NAMUR standard):

EL3174 / EL3174-0090

Input form: voltage differential, current single ended;

Signal range: Voltage -10/0~+10V, Current -20/0/4~20mA;

EL3174-0090 is equipped with TwinSAFE SC safety function.

EL3174-0002

Full channel electrical isolation (2500V withstand voltage), voltage/current are differential inputs;

EL3174-0032

Low voltage version: voltage range -3/0~+3V, the rest is the same as EL3174-0002;

Commonality: Supports NAMUR NE43 fault diagnosis and can identify sensor disconnection and signal out of bounds.

2. General environmental and electrical parameters

Working temperature: standard 0~55 ℃; Extended temperature range * * -25~+60 ℃ * *; Storage -40~+85 ℃;

Humidity: 5%~95% RH, no condensation;

E-Bus power consumption: single/2-channel typical 130mA, 4-channel approximately 170mA;

Certification: CE and cULus are standard across the entire range; Some models support ATEX and IECEx explosion-proof certification;

Immunity: Complies with EN 61000-6-2/4 electromagnetic compatibility standards, and vibration and impact meet EN 60068.

EtherCAT Communication Fundamentals

1. Wiring and hardware requirements

Cable: Use Cat5 and above Ethernet cables, RJ45 interface, and only use 4 signal cables; The maximum distance between devices is 100m; automatic recognition of straight/cross lines.

E-Bus bus: The maximum output of the coupler is 2A. When the current is insufficient, an EL9410 feeding terminal needs to be installed, and the entire module must be grounded.

2. Watchdog

Built in SM synchronization manager watchdog, PDI process data watchdog, default timeout of 100ms:

When communication is interrupted, the module automatically switches to a safe state and outputs a lock;

The timeout period can be configured in TwinCAT, with an adjustable range of 0 to approximately 170 seconds.

3. EtherCAT state machine

Standard 5 operating states, switch in order when powered on:

Init: Initialization, no communication;

Pre op: Only available for email communication, no periodic process data;

Safe op: Process data is refreshed normally, and the output is locked in a safe state;

Op: Normal operation, fully functional enabled (main working state);

Boot: Dedicated for firmware upgrade, entry is prohibited under normal operating conditions.

4. CoE interface (CANopen over EtherCAT)

Using index+sub index (hexadecimal) to manage all parameters is the core interface for module configuration and diagnosis:

0x1000 segment: read-only identity information such as device model, serial number, firmware, etc;

0x6000/0x7000: Periodic Process Data PDO;

0x8000 segment: Read and write parameters for filtering, range, calibration, channel configuration, etc;

Additional features:

NoCoStorage: Turn off parameter power-off saving to reduce EEPROM erase loss;

Startup list: Pre stored parameters, automatically loaded when the module is powered on, no need to reconfigure when changing devices.

5. Distributed Clock (DC)

The entire system supports EtherCAT distributed clock, with a clock reference of 1ns and master-slave synchronization accuracy of less than 1 μ s. It is suitable for scenarios with high timing requirements such as multi axis and synchronous acquisition.

Mechanical installation and electrical wiring

1. Installation specifications

Rail: Standard 35mm DIN rail, rail must be reliably grounded;

Disassembly and assembly: After turning off the power, pull the orange buckle to unlock, and do not forcefully break it; The modules are tightly spaced without any gaps;

Mechanical reinforcement: In high vibration scenarios, the length of the module string needs to be limited, and the distance between the fixed points of the guide rail is 5cm, using countersunk screws;

Installation posture: There is no mandatory restriction on posture, and a ventilation gap needs to be reserved for up and down;

Explosion proof supplement (ATEX): Explosion proof scenarios require installation in enclosures with an IP54 rating or higher. It is prohibited to plug or unplug terminals or connect wires when live.

2. Wiring system

Terminal type: screw free spring terminal, compatible with 0.08-2.5mm ² cable, stripping length 8-10mm;

Shielding requirements: Analog signal lines must use shielded twisted pair cables, with a single point grounding on the shielding layer;

Potential key (key for differential current input): Strictly control the common mode voltage Ucm, exceeding the limit will cause measurement distortion; The internal GND of 1/2 module can be connected to an external potential, while the GND of 4 modules can be short circuited to 0V from the power supply. It is strictly prohibited to mix high and low potential sensors.

3. LED status indication

All modules are equipped with a green RUN light+(some red ERROR fault lights), and the logic of the indicator lights is unified:

RUN off: Init/Boot status;

RUN flashing: Pre Op status;

RUN single flash: Safe On state;

RUN constantly on: Normal Op state;

ERROR red light on: corresponding to channel disconnection, over range, under range (voltage type part has no fault light, only process word alarm).

4. Special wiring instructions

Single ended/differential differentiation: Detailed definition of the wiring logic and reference potential difference between two types of inputs;

Sensor adaptation: distinguish the wiring scheme of two-wire/three wire/four wire current transmitters;

UL specification: When used in North America, a 4A fuse or NEC Class2 power supply is required for power supply, and it is prohibited to connect to telecommunications lines.

Definition of Analog Technology and NAMUR Standard

1. Interpretation of Basic Simulation Terminology

Full Scale (FSV): The nominal maximum signal value of the equipment, which serves as the benchmark for error calculation;

Measurement error: calculated as a percentage of full scale, including comprehensive errors such as temperature drift and noise;

Temperature coefficient (tK): unit ppm/K, used to calculate additional errors at different temperatures;

Single end/differential: Single end uses the internal GND of the module as a reference, and differential measures the difference between two signals, making it more resistant to interference;

Common mode voltage and dielectric strength: defining module withstand voltage and potential limits, are the core basis for wiring compliance.

2. Timing of AD conversion

Introduce the full chain delay of ADC sampling, filtering, and data processing, distinguish between sampling rate and signal delay, and divide them into two indicators: step response and linear delay.

3. NAMUR NE43 standard

Define the fault signal interval for the 4-20mA current circuit:

Effective measurement area: 3.8~20.5 mA;

Fault zone: ＜ 3.8mA or ＞ 20.5mA, corresponding to sensor disconnection or fault;

The EL31xx series is compatible with this standard and can automatically identify and report faults.

TwinCAT configuration and debugging

1. Preconditions

Install TwinCAT real-time driver on the network card to distinguish between correct and incorrect driver configurations;

Import/update ESI device description files, which can be upgraded online through the software's built-in ESI update tool;

Supports two modes: offline configuration (no hardware advance planning) and online scanning (hardware automatic recognition).

2. General configuration process

Create a new project and bind the EtherCAT master network card;

Scan online or manually add EL31xx terminals offline;

Choose PDO mode (Standard/Compact): Standard mode=Value+Status Word, Compact mode=Only Value, Simplify Bus Load;

CoE parameter configuration: filtering, range, offset, gain, channel mode (EL3174 switching voltage/current);

Variable mapping, compilation, activation, and startup.

3. Operation mode

FreeRun: default mode, triggered by a timer for sampling, affected by filters;

Synchron: Frame synchronization mode, turn off filtering, faster response speed;

DC synchronous mode: relying on distributed clocks, multiple modules synchronously collect data.

4. Filter configuration

Built in FIR (50/60Hz power frequency notch) and IIR digital filters, 50Hz mode power frequency attenuation>50dB, can be globally set through CoE.

5. TwinSAFE SC configuration

Introduce the safety channel configuration and process data mapping for EL3124-0090 and EL3174-0090 safety models, which can use standard analog signals for safety control systems.

6. Programming support

Compatible with IEC 61131-3 full programming languages (ST, LD, FBD, SFC, etc.), it can realize logic such as acquisition, threshold alarm, signal conversion, etc.

Fault diagnosis, maintenance, and firmware

1. Third level diagnostic method

Hardware LED: Quickly locate communication and channel faults;

Process data status word: Read over range, under range, disconnection, communication error;

CoE diagnostic register: reads raw ADC values, temperature, and detailed fault codes.

2. Common faults and troubleshooting

Communication abnormalities: network cable damage, insufficient E-Bus power supply, watchdog timeout, EtherCAT status abnormality;

Inaccurate measurement: common mode voltage exceeding the standard, poor shielding, improper filtering parameters, calibration offset;

Alarm constantly on: sensor disconnection, signal exceeding range, wiring error.

3. Firmware and device maintenance

Firmware classification: Controller firmware (. efw), FPGA firmware (. rbf), supports single/batch upgrades;

Parameter reset: restore factory settings through the CoE command;

Spare parts replacement: High revision versions can directly replace lower versions without the need for reconfiguration;

Long term storage: If not used for more than 5 years, the bus capacitor needs to be re energized before powering on.