BECKHOFF EL70x7 Stepper Terminal Maintenance Guide

Error A: Red constant light, Phase A output stage error: Temperature>100 ° C, short circuit, etc

Error B: Red constantly on, Phase B output stage error: Temperature>100 ° C, short circuit, etc

2.3 K-bus/E-bus diagnosis

When the terminal is connected to the K-bus (bus terminal), the K-BUS ERR LED of the power terminal will indicate an error with a specific flashing code (see the subsequent troubleshooting section of this article). When connected to the E-bus (EtherCAT terminal), the L/A LED flashes to indicate data communication.

CoE parameter configuration and key objects

All operational parameters of EL70x7 are configured through the CANopen over EtherCAT (CoE) object directory. The following are the most commonly used objects in on-site debugging.

3.1 Basic parameters of motor (0x8010)

Index Name Unit Description

0x8010:01 Maximum current 1 mA Maximum continuous coil current. EL7037 defaults to 5000mA (5A), but the actual terminal rating is limited.

0x8010:02 Reduced current 1 mA Reduced current at rest (energy-saving mode)

0x8010:03 Nominal voltage 10 mV motor rated voltage (non supply voltage). Used for model calculations.

0x8010:04 Motor coil resistance 10 m Ω Motor phase resistance

0x8010:05 Motor EMF 1 mV/(rad/s) Back electromotive force constant (for sensorless mode)

0x8010:06 Motor full steps - The number of motor full steps. Usually 200 (1.8 ° step angle)

0x8010:07 Encoder increments (4-fold) The number of pulses per fourth harmonic of the encoder per revolution. AS10xx motor comes standard with 1024 inc → 4096

3.2 Operation Mode and Function Selection (0x0012)

Description of allowed values for sub index names

0x8012:01 Operation mode 0=automatic, 1=direct speed, 3=position control, 4=extended speed, 5=extended position, 6=no sensor default 0 (automatic mode, automatically switched according to PDO)

0x8012:05 Speed range 0~5 corresponds to a maximum stride frequency of 1000~32000 full steps/s. Default 2000 full steps/s

0x8012:08 Feedback type 0=encoder, 1=internal counter position feedback source. Default internal counter

0x8012:09 Invert motor polarization 0/1 Reverse motor rotation direction

0x8012:0A Error on step loss 0/1 Do you consider step loss as an error

0x8012:0B Fan cartridge present 0/1 Notify that ZB8610 fan has been installed on the terminal

3.3 Positioning Interface Parameters (0x0020)

When using the Positioning interface mode, the following parameters are used for stroke control:

Index Name Range/Unit Description

0x8020:01 Velocity min. 0-10000 Minimum set speed (percentage of speed range)

0x8020:02 Velocity max. 0-10000 Maximum set speed

0x8020:03/04 Acceleration pos./neg. ms Forward/reverse acceleration time (from 0 to 100% speed)

0x8020:05/06 Deceleration pos./neg. ms forward/reverse deceleration time

0x8020:07 Emergency deceleration ms Emergency stop deceleration time

0x8020:08 Calibration position inc is the absolute position set after completing the zeroing process

0x8020:0B Target window inc Target window, within this range is considered 'arrived'

0x8020:0E Modulus factor inc Modulus factor (such as the increment corresponding to 360 °)

3.4 Controller Parameters (0x8014)

Index Name Description

0x8014:01 Feed forward (pos.) position feedforward

0x8014:02 Kp factor (pos.) position loop proportional gain

0x8014:03 Kp factor (velo.) Speed loop proportional gain (unit: 0.1 mA/(rad/s))

0x8014:04 Tn (velo.) velocity loop integral time constant (unit: 0.01 ms)

Detailed explanation and selection of operating modes

EL70x7 supports multiple operating modes, each suitable for different application scenarios and motor types.

4.1 Automatic mode (default)

The terminal automatically switches between speed and position controllers based on the selected predefined PDO allocation. Not applicable to extended mode. For applications that do not require magnetic field orientation control, this mode is recommended.

4.2 Velocity direct mode

Set the speed through the loop variable STM Velocity (0x7010:21), with a range of ± 32767 corresponding to ± 100% speed range.

Support internal counter or encoder feedback.

It can be controlled through TwinCAT NC or direct PLC.

4.3 Position controller mode

Set the target position in increments using STM Position (0x7010:11).

When using an internal counter, one revolution of AS10xx motor corresponds to an increment of 12800, which is 200 full steps x 64 micro steps.

When using an external encoder, one circle corresponds to 4 encoder lines (e.g. 1024 lines → 4096 increments).

4.4 Extended Velocity/Position Mode

Based on field oriented control (FOC), the stepper motor is controlled as a servo motor.

Only supports Beckhoff AS10xx series motors.

An encoder must be connected with a resolution of at least 4000 inches per revolution.

When enabled, commutation determination needs to be performed: the rear axle will be slightly swung forward and backward several times to determine the rotor position. During this period, the external load torque must be extremely small.

Advantages: Completely eliminate resonance, load adaptive current, high efficiency, and no step loss.

4.5 Velocity sensorless mode

By analyzing the back electromotive force, load adaptive current control can be achieved without the need for an encoder.