Bonfiglioli EM-ENC-03 Expansion Module Configuration and System Bus Integration Guide

Bonfiglioli Vectron EM-ENC-03 Expansion Module: Professional Installation and System Bus Integration Guide

The demand for expanding the functions of frequency converters is increasing in complex industrial automation drive systems. Bonfiglioli Vectron provides EM-ENC-03 expansion modules for its ACTION and ACTION Cube series inverters to supplement the functionality of standard equipment. This module not only integrates the second incremental speed sensor input, but also provides a system bus interface based on CAN High Speed, enabling the frequency converter to be seamlessly integrated into the CANopen network. This article will delve into the hardware installation steps, core parameter configuration, and communication mechanism of the module in the system bus, providing engineers with a practical technical reference.

Module Overview and Hardware Installation

The main function of the EM-ENC-03 expansion module is to add a CAN system bus interface (compliant with ISO-DIS 11898 standard, with a maximum communication rate of 1 MBaud) and an additional speed sensor input interface to the ACT/ACU series frequency converter. Before starting any installation work, safety regulations must be strictly followed.

1. Precautions for mechanical installation

The installation process must be carried out after the inverter is completely powered off and waiting for the DC bus capacitor to discharge completely. Operators need to have corresponding qualifications.

Remove the cover plate at the bottom of the frequency converter to expose the expansion card slot.

Insert the EM-ENC-03 module vertically into the slot and ensure that the buckle is in place.

Reinstall the bottom cover plate. After power on, the module is ready.

The manual emphasizes that do not touch the PCB board on the back of the module to prevent static electricity from damaging the components.

2. Electrical connections and pin definitions

The electrical connection of the module is mainly completed through two sockets:

X410A (speed sensor interface): Supports 5V push-pull signal (compliant with RS-422A/RS-485) or 10V-24V single ended signal. Pins 1-4 correspond to differential signal inputs A+, A -, B+, and B -, respectively.

X410B (System Bus Interface): Provides CAN bus connection. Pin 5 is CAN Low, pin 6 is CAN High, and pin 7 is CAN-GND.

Key configuration: Terminal resistor

The manual states that terminal matching is required at both ends of the bus. DIP switches S1 and S2 are integrated on the module for configuring bus terminals:

Passive terminal: S1=ON, S2=OFF.

Active terminal: S1=ON, S2=ON (recommended for long-distance wiring to improve signal edge characteristics).

Note: Active terminals can only be enabled on one node in the network.

System bus (CAN) core configuration

The core value of a module lies in its system bus functionality. Correctly configuring node addresses and communication rates is a prerequisite for network communication.

1. Node ID and baud rate settings

Node ID: Set through parameter 900. The effective range is 1-63. -1 is the default value, indicating that the system bus is disabled; 0 indicates that the frequency converter is defined as a master station. In a network, there can only be one master station.

Baud Rate: Set through parameter 903. This value must be consistent with all nodes in the network. The bus length is inversely proportional to the baud rate, for example: 50 kBaud corresponds to a maximum of 1000 meters, while 1000 kBaud only supports 25 meters.

2. Network Management (NMT) and Startup Sequence

The system bus follows the CANopen DS 301 standard. The master station is responsible for controlling the startup sequence of the slave stations.

After power on, all slave stations are in Pre Operational state, which only supports SDO parameter access and cannot exchange PDO process data.

After the master station sends the Start Remote Node command, the slave station switches to the Operational state and begins the process of data exchange.

Parameter 904 (Boot Up Delay) allows the master station to delay sending startup commands after initialization to ensure that all slave stations (especially external components that start slowly) are ready.

PDO and SDO: Detailed Explanation of Process Data and Parameter Channels

Understanding PDO (Process Data Object) and SDO (Service Data Object) is the core of using this module to implement data exchange.

1. SDO channel (parameter data)

SDO is used for reading and writing parameters of frequency converters. Each device supports two SDO channels:

SDO1: Used for the master station (such as PLC or master station frequency converter) to access slave station parameters through client SDO.

SDO2: Reserved connections for visualization tools or debugging software.

The manual emphasizes that SDO communication adopts "Expedited Transfer" and only supports uint/int/long data types. This means that all parameters mapped to these data types can be read and written through the network. For example, when accessing the system bus through the Profibus DP gateway, the reserved bytes in the communication channel (PKW) can be used to specify the node ID of the target slave station.

2. PDO channel (process data)

PDO is used for real-time exchange of dynamic data such as control words, status words, and frequency setpoint values. Each device supports 3 sets of TxPDO (transmit) and 3 sets of RxPDO (receive).

Identifier: By default, it follows the CANopen predefined connection set, for example, the identifier for TxPDO1 is 384+Node ID. Parameters 925, 927, etc. can be modified to resolve ID conflicts.

Transmission mode: Set through parameters 930-938. Supports time triggered (Cycle) and synchronous triggered (SYNC). In synchronous mode, all nodes simultaneously latch the input data and update the output data upon receiving the SYNC message sent by the master station, ensuring the synchronization of system control.

Timeout monitoring: Parameters 939, 941-945 are used to monitor the timeout of SYNC messages or RxPDO reception. Once the timeout occurs, the frequency converter will trigger a fault (such as F2200 system bus SYNC timeout) and safely shut down.

Virtual Links and Application Instances

This is one of the most powerful features of the EM-ENC-03 module. It allows users to map the internal functional blocks of the frequency converter (such as PID regulator output, frequency setpoint) to the input of another frequency converter through the system bus, without relying on PLC for relay.

1. Principle mechanism

The output data of each functional block is assigned a "Source Number". For example, the source number of the control word is 740, and the source number of the output frequency is 62. For the data received by RxPDO, the system will map it to a specific source number (such as RxPDO1 Byte 0 mapped to source number 700).

By setting the "input link" parameter of TxPDO (such as 950 TxPDO1 Word1) and entering the corresponding source number, the data of that source can be placed in a specific byte position in the PDO message. The receiver can complete the cross device 'virtual link' by configuring its functional block input parameters to point to the source number mapped by RxPDO.

2. Configuration Example

Assuming that the control word (source 740) of frequency converter 1 needs to be sent to frequency converter 2:

Inverter 1 (sender): Set parameter 950 (TxPDO1 Word1) to 740.

Inverter 2 (receiver): Set the control word parameter 99 (Control Word) to 704 (i.e. the source number of RxPDO1 Byte 0).

In this way, the control word of frequency converter 2 is synchronized with frequency converter 1, achieving master-slave control or synchronous start stop.

Speed sensor input and actual value monitoring

The second speed sensor input (speed sensor 2) provided by EM-ENC-03 enhances the redundancy and control accuracy of the system.

1. Configuration and selection

Operation Mode: Parameter 493. Support "Quadruple evaluation", which can identify the direction of rotation through A/B phase signals.

Division Marks: Parameter 494. It must be calculated based on the sensor model and motor speed to ensure that the input frequency does not exceed the limit value of 300kHz.

Level: Parameter 495. Optional "Push pull" or "Unipolar".

2. As an actual value source

Through parameter 766 (Actual Speed Source), users can choose speed sensor 1 (main body) or speed sensor 2 (expansion module) as the feedback source for speed closed-loop control. In addition, the signal from speed sensor 2 can also be used as a frequency reference source (reference frequency source 475 is set to 34 or 35) to achieve given control based on external speed measurement.

Fault diagnosis and system capacity planning

1. Common fault codes

The module will trigger specific fault codes to assist in diagnosis:

F2200: SYNC message timeout.

F2201-F2203: RxPDO1-3 data reception timeout.

F2210: CAN controller Bus Off. Triggered when the error counter overflows, the controller will automatically reinitialize afterwards.

2. Bus load planning

To ensure network stability, it is necessary to calculate the bus load rate. The manual provides calculation formulas and tables. In the worst case, a PDO message is about 140 bits. It is recommended to control the bus load rate below 80%, and if it exceeds 90%, it is considered a high-risk area.