Bonfiglioli Vectron EM-RES-01 Expansion Module Rotary Transformer Interface Configuration Guide

Bonfiglioli Vectron EM-RES-01 Expansion Module Rotary Transformer Interface Configuration Guide

In the field of industrial servo drive and synchronous motor control, precise detection of rotor position is the core prerequisite for ensuring efficient and smooth operation of motors. Although incremental encoders are widely used, their reliability often faces severe challenges in harsh environments such as high temperature, vibration, and oil pollution. As an electromagnetic position sensor, the rotary transformer (Resolver) has become the preferred feedback solution for heavy-duty servo and permanent magnet synchronous motor (PMSM) control due to its durability, anti pollution, and high temperature resistance.

The Bonfiglioli Vectron ACTION and ACTION Cube series frequency converters have introduced a rotary transformer interface through the EM-RES-01 expansion module for drive systems that originally only supported incremental encoders, while retaining analog input and CAN system bus functions, making standard frequency converters capable of high-precision and high reliability synchronous motor control applications.

Overview and Functional Positioning of EM-RES-01 Expansion Module

1.1 Module Core Functions

EM-RES-01 is an optional hardware expansion component designed by Bonfiglioli Vectron for the ACTION and ACTION Cube series frequency converters, supporting software versions 4.1.0 and higher for the ACTION series and all ACU series devices. This module achieves the following functional extensions by inserting it into the lower expansion slot of the frequency converter:

CAN system bus interface: compliant with ISO-DIS 11898 (CAN High Speed) standard, supporting a maximum communication rate of 1 MBaud

Resolver Interface: Excitation voltage output and SIN/COS signal input

Analog input (EM-S1INA): 12 bit resolution, configurable for ± 10V voltage or ± 20mA current input

Repetitive frequency output (EM-RFOUT): Simulate the Resolver signal into an incremental encoder signal output (A+/A -/B+/B -)

1.2 Positioning Differences between EM-IO Series and EM-RES-01

Functions EM-IO-01~04 EM-RES-01

CAN system bus support

Analog input support (1 channel) Support (1 channel)

Digital input/output support not supported

Analog output support (some models) not supported

Temperature monitoring (PTC/KTY) supported (02/03/04) not supported

The interface of the rotary transformer is not supported

Repetitive frequency output is not supported

Core value positioning: EM-RES-01 is a specialized extension module designed for closed-loop control of synchronous motors in the EM-IO series. It sacrifices universal I/O and integrates a complete rotary transformer interface, enabling standard ACTIVE/ACU frequency converters to drive permanent magnet synchronous motors and achieve high-precision speed and position control.

Technical specifications for rotary transformer interface

2.1 Electrical specifications

The rotary transformer interface of EM-RES-01 has the following key electrical parameters:

Parameter specification description

The excitation voltage (REF) 4V (effective value) is provided to the AC excitation of the primary winding of the rotary transformer

Excitation current Imax=60mA driving capability limit

SIN/COS input voltage 2V (effective value) feedback signal from the secondary winding of the rotary transformer

Input voltage withstand 30V overvoltage protection capability

Input impedance>95 Ω @ 5kHz/20kHz matched with rotary transformer

The maximum number of pole pairs is 24, which is suitable for multi pole rotating transformers

Maximum speed of 30000 rpm (pole pairs=1) High speed application capability

Phase offset of 7 ° (5kHz)/14 ° (10kHz)/26 ° (20kHz) varies with excitation frequency

2.2 Selection of Incentive Frequency

The excitation frequency of the rotary transformer can be selected through parameter 380 (Operation Mode):

Applicable scenarios for mode frequency

5 5 kHz long line transmission, low-speed application

10 kHz universal recommended settings

High speed applications with 20 kHz and low latency requirements

Selection tip: The selection of excitation frequency should take into account the cable length, specifications of the rotary transformer, and the maximum speed of the motor. The higher the frequency, the faster the signal update rate, but the greater the cable attenuation and phase shift.

2.3 Matching of pole pairs for rotary transformers

Parameter 381 (No. of Pole Pairs) is used to set the number of pole pairs for the rotary transformer, with a range of 1-24 and a factory value of 1.

Key constraint: For synchronous motor control, the ratio of the number of motor poles to the number of rotating transformer poles must be an integer. For example, a 4-pole pair motor paired with a 2-pole pair rotary transformer (ratio=2) is acceptable, but paired with a 3-pole pair rotary transformer (ratio=4/3) is not allowed. If the ratio is not an integer, the frequency converter will report fault F1423.

Wiring specifications for rotary transformers

3.1 Terminal Definition

The rotary transformer interface of EM-RES-01 is located at socket X410A (terminals 1-6):

Terminal signal description