Bonfiglioli Vectron EM-ENC-03 Second Encoder Interface and System Bus Expansion Guide

Bonfiglioli Vectron EM-ENC-03 Second Encoder Interface and CAN System Bus Expansion Guide

In high-performance servo drive and multi axis synchronous control systems, redundant or dual channel speed feedback is often the key to achieving high-precision and high reliability control. The EM-ENC-03 expansion module provided by Bonfiglioli for the ACTION and ACTION Cube series inverters is a streamlined solution designed for this requirement. It integrates the second high-speed incremental encoder interface and CAN system bus function, enabling the frequency converter to connect to the distributed control network and simultaneously receive speed feedback signals from external encoders.

Chapter 1: EM-ENC-03 Hardware Architecture and Installation Points

EM-ENC-03, as a functional expansion component of the frequency converter, is installed in the lower slot of the device. Unlike the more feature rich EM-ENC-02, EM-ENC-03 focuses on two core functions: high-speed encoder input (second encoder) and CAN system bus (CANopen protocol stack).

1.1 Hardware functional modules

According to the instructions in Chapter 2 and Chapter 3 of the manual, EM-ENC-03 provides the following functions:

CAN system bus interface: compliant with ISO-DIS 11898 (CAN High Speed) standard, supporting a maximum transmission rate of 1 MBaud, used for real-time data exchange between frequency converters.

Speed sensor input (second encoder): differential/push-pull encoder interface, maximum input frequency of 300 kHz, supports quadruple frequency evaluation of A/B dual channel signals.

1.2 Mechanical Installation and Safe Operation

The installation process must strictly follow the following safety steps:

Safe power-off: The module installation can only be carried out after the frequency converter has completely cut off the power and waited for the DC bus capacitor to discharge (at least 3 minutes).

Module insertion: EM-ENC-03 is pre installed in the housing, and touching the exposed PCB board on the back is prohibited to prevent damage to components caused by electrostatic discharge (ESD). Align the module with the lower slot and insert it smoothly until it is fully seated.

Cover plate reset: After installation, the lower cover plate needs to be reinstalled in place. After powering on again, the module automatically enters the ready state.

1.3 Definition of Wiring Terminals

EM-ENC-03 provides two connection sockets (Chapter 3.3.2):

X410A (encoder input):

Terminal 1: Encoder A+signal

Terminal 2: Encoder A - Signal

Terminal 3: Encoder B+signal

Terminal 4: Encoder B - Signal

Terminals 5 and 7: Undefined (no function)

Terminal 6: Ground (GND)

X410B (CAN system bus):

Terminal 5: CAN_L (CAN low line)

Terminal 6: CAN-H (CAN high wire)

Terminal 7: CAN_GND (CAN signal ground)

Terminals 1-4: Undefined (no function)

Chapter 2: 300kHz High Speed Encoder Interface Configuration

The core function of EM-ENC-03 is its second high-speed encoder interface, which supports input frequencies up to 300 kHz and is suitable for closed-loop control applications with high-resolution encoders and high dynamic response.

2.1 Hardware signal compatibility and terminal resistance configuration

The encoder interface selects the working mode through the parameter Operation Mode Speed Sensor 2 493 (Chapter 5.1):

0 (Off): Speed measurement disabled

4 (Quadruple Evaluation): Quadruple Evaluation - Counting the four edges of the A/B signal can achieve the highest resolution speed measurement, recommended for high-precision speed closed-loop.

104 (Quadruple Evaluation Inverted): Same as Mode 4, but with the velocity value reversed (equivalent to exchanging A/B phase signals).

The interface is compatible with two signal types, which can be selected through the parameter Level 495 (Chapter 5.1.3):

Level=0 (push-pull/differential): A 5V differential signal (A+/A -, B+/B -) that complies with the RS-422A/RS-485 standard, with strong anti-interference ability and suitable for long-distance transmission.

Level=2 (single ended): 10V~24V single ended HTL signal, only using A+and B+terminals, suitable for traditional industrial encoders.

Terminal resistor configuration (DIP switch S3) (Chapter 5.1.1):

For 5V RS-422 differential signals, the built-in 150 Ω terminal resistor can be activated through DIP switch S3:

Both switches of S3 are placed in the ON position: activate the terminal resistor

Both switches of S3 are in the OFF position: the terminal resistor is not activated

Key warning: The two switches of S3 must be placed in the same position at the same time, otherwise it may cause damage to the components. For 24V single ended HTL signals, there is no need to activate terminal resistors.

2.2 Encoder line count calculation and parameterization

The number of lines (PPR pulses per revolution) of the encoder is set through the parameter Division Marks Speed Sensor 2 494 (range 1~8192, default 1024).

Maximum allowable line count calculation (Chapter 5.1.2):

The maximum number of lines is determined by the upper limit of the encoder input frequency (300 kHz) and the maximum motor speed:

Smax=three hundred thousand Hz×sixty s/min nmax

S