Bonfiglioli Vectron EM-RES-02 Expansion Module Installation and Configuration Guide

Bonfiglioli Vectron EM-RES-02 Expansion Module Installation and Configuration Guide

Module Overview and Applicable Scenarios

The EM-RES-02 expansion module launched by Bonfiglioli Vectron is a specialized hardware option for ACT and ACU series inverters, designed to supplement industrial drive systems with high-precision analog processing, rotary transformer (Resolver) signal resolution, and frequency signal regeneration functions. This module is fully supported by the ACU series and requires the ACT series firmware version to be no less than 4.1.0. In practical engineering, when the original drive system needs to be connected to a second bipolar analog signal, or when a third-party rotary transformer interface needs to be replaced, or when the rotary transformer signal needs to be converted into incremental pulse output for synchronous acquisition by the upper computer, EM-RES-02 provides an integrated and low latency solution.

Unlike conventional standalone signal converters, EM-RES-02 adopts a direct insertion chassis structure and is directly installed in the expansion slot below the frequency converter, without the need for additional external power supplies and signal conditioning boxes, significantly reducing the complexity of wiring inside the cabinet. Its core functions include:

Second bipolar analog input (EM-S1INA), switchable voltage (± 10V) or current (± 20mA) mode, with a resolution of 12 bits;

Rotating Transformer Input Interface (EM-RES), supporting excitation frequencies of 5/10/20kHz, compatible with up to 24 pairs of poles of rotating transformers, with a maximum measurable speed of 30000rpm;

Repetitive frequency output (EM-RFOUT) simulates the rotary signal as a 1024 line incremental encoder signal (A+/A -, B+/B -, R+/R -), making it easy to connect to external controllers or speed cards.

This article focuses on practical engineering installation, parametric configuration, and troubleshooting, combined with key details in the module technical manual, to provide on-site engineers with an actionable technical literature.

Safety regulations and preparation before installation

Before performing any mechanical or electrical operation, the following safety guidelines (based on EN 50178, IEC 60364, and BGV A2 standards) must be strictly followed:

Power outage and discharge: The main circuit of the frequency converter (power supply, DC bus, motor terminals) may still carry dangerous voltage after disconnecting the power supply, and must wait for at least a few minutes until the DC bus capacitor is completely discharged. Use a multimeter to confirm that the bus voltage is below 36V before operation.

Electrostatic protection: The back PCB of EM-RES-02 module is exposed and must not be touched to avoid damage to sensitive components caused by electrostatic discharge (ESD). Operators should wear grounding wristbands.

Wiring specification: All control signal lines (especially rotary differential lines) must use twisted pair shielded cables, with the shielding layer connected to the protective earth (PE) at both ends (frequency converter side and motor side) to suppress common mode interference.

Qualification requirements: Only professional personnel familiar with frequency converter installation and possessing electrical safety knowledge are allowed to implement.

Before installation, please confirm the inverter model and firmware version - if it is the ACT series, you need to check the software version through the operation panel or debugging software to ensure that it is ≥ 4.1.0; The ACU series does not have this restriction. Prepare small screwdrivers, wire strippers, and shielding crimping tools at the same time.

Mechanical installation steps

The EM-RES-02 module is designed as a plug-in structure and installed at the original cover plate position below the frequency converter. The specific process is as follows:

Remove the lower cover plate: Use a screwdriver to loosen and remove the plastic cover plate (marked as "1") at the bottom of the inverter, exposing the dedicated expansion interface socket (Slot).

Check module orientation: The metal shielding shell of the module is facing outward, and the PCB connector is facing towards the inside of the frequency converter. Pay attention to the positioning card slot at the front end of the module to ensure alignment with the guide rail.

Vertical insertion: Apply even force to press the module into the slot until a "click" sound is heard, indicating that it is locked in place. It is strictly prohibited to tilt or shake the insertion to avoid bending the needle.

Reset the cover plate: Reinstall the original lower cover plate to maintain the protection level and integrity of the cooling air duct.

After installation, power on the frequency converter and the module will automatically enter standby mode without the need for additional drivers or firmware upgrades. If there is an unrecognizable situation, check whether the pins are oxidized or bent.

Electrical connections and terminal definitions

EM-RES-02 provides two sockets: X410A (6 bits) and X410B (7 bits), corresponding to the rotary converter interface, analog input, and frequency output, respectively. The detailed allocation is shown in the following table:

Explanation of socket terminal number and signal name

X410A 1 REF+positive terminal of rotary excitation

X410A 2 REF - Rotary converter excitation negative terminal

X410A 3 SIN - Rotating sine signal negative

X410A 4 SIN+spiral sine signal positive

X410A 5 COS spiral cosine signal negative

X410A 6 COS+spiral cosine signal sine

X410A 7 RFOUT A+frequency output A-phase positive (RS-422)

X410B 1 RFOUT A-frequency output A-phase negative

X410B 2 RFOUT B+frequency output B phase positive

X410B 3 RFOUT B-frequency output B-phase negative

X410B 4 S1INA Analog Input (Voltage/Current)

X410B 5 RFOUT R+zero position reference signal positive

X410B 6 RFOUT R-zero reference signal negative

X410B 7 GND analog input ground (reference ground)

Key wiring points:

The rotary transformer cable adopts twisted pair shielding, and SIN+/SIN - and COS+/COS - are independently twisted, and the excitation line (REF+/REF -) also needs to be twisted. The shielding layer is grounded at both ends, with the grounding impedance as low as possible.

If the analog input adopts current type (4-20mA), the internal switch S3 of the module needs to be turned to the "ON" position (upward), and a 250 Ω resistor should be connected in parallel between terminal X410B. 4 and GND (built-in in the module, no external connection required). Set the voltage mode (± 10V) to "OFF" (downward), with an input impedance of 100k Ω.

The frequency output is differential RS-422/RS-485 level, with a maximum load current of ± 60mA and a minimum load impedance of 150 Ω. It can be directly connected to the PLC high-speed counting module or motion controller.

Detailed configuration of analog input (EM-S1INA)

5.1 Input Mode and Feature Settings

After selecting voltage or current through switch S3, the input-output characteristic curve needs to be defined by parameters. Using a two-point linear mapping, the two feature points (X1, Y1) and (X2, Y2) correspond to the input percentage and output percentage (relative to the maximum frequency or maximum percentage), respectively. The four key parameters are:

564 feature point X1 (default -98.00%): Input percentage of the first point;

565 feature point Y1 (default -10.000%): Output percentage of the first point;

566 feature point X2 (default 98.00%): Input percentage of the second point;

567 feature point Y2 (default 100.00%): Output percentage of the second point.

Among them, the input percentage is 100% at full scale (10V or 20mA), and the output percentage is 100% at 419 maximum frequency or 519 maximum reference percentage. For example, if the maximum frequency is set to 50Hz, then Y=100% corresponds to 50Hz.

5.2 Four working modes (parameter 562)

According to application requirements, the following feature transformations can be selected:

Mode 1- Bipolar: Direct mapping, allowing negative input to generate negative frequency (inversion).

Mode 11- Unipolar: Clamp the negative input to zero, suitable for situations where only forward rotation is required.

Mode 21- Monopolar 2... 10V/4... 20mA: Forcefully compresses the 0-20% input range to zero output, commonly used for industrial sensors with "active zeros" to ensure that the signal is not driven below the threshold.

Mode 101- Bipolar Absolute Value: Absolute value is taken for the output, negative input generates positive speed, but input polarity still affects direction judgment.

In practical engineering, if a 4-20mA signal is used and forward and reverse rotation is required, mode 1 can be combined with current type input. The characteristic point X1 is set to 20% (corresponding to 4mA), which corresponds to the negative maximum, and X2 is set to 100% (corresponding to 20mA), which corresponds to the positive maximum, with a linear transition in the middle.

5.3 Dead zone/hysteresis and filtering

560 Tolerance Band: default 2.00%, used to define the dead zone range near zero crossing to prevent speed jitter caused by signal noise. For example, 2% of the voltage signal corresponds to 0.2V, and the output remains at zero or minimum frequency when the input is within ± 0.2V.

561 filtering time constant: optional 0-5000ms (15 levels), using first-order low-pass filtering to smooth out reference value mutations caused by interference or measurement fluctuations. For tension control with fast response requirements, it is recommended to set it to below 4ms; For slow temperature regulation, it can be increased to several hundred milliseconds.

5.4 Fault Monitoring and Adjustment

Parameter 563 error/warning behavior configurable response to input signal too low (<1V or<2mA):

0: Do not monitor;

1: Only issue warnings;

2: Warning and slow down to stop the machine (according to stopping method 1);

3: Warning+malfunction, free parking.

This monitoring is independent of the enable status of the frequency converter and is particularly important for safety critical applications.

Due to component errors, it may be necessary to make 568 adjustments to the analog signal: first short-circuit the input to ground and select "Adjust 0V/0mA"; Connect to precise 10V (or 20mA) and select "Adjust 10V/20mA". Automatically saving adjustment values can greatly improve measurement accuracy.

Interface calibration and startup of rotary transformer

The interface of the rotary transformer is the core advantage of EM-RES-02, and its processing flow includes excitation frequency setting, pole pair matching, offset calibration, and speed source selection.

6.1 Basic parameter settings

380 working mode: Select excitation frequency (5kHz, 10kHz, 20kHz) that is consistent with the specifications of the rotary converter. The higher the frequency, the faster the position update rate, but the phase delay also increases (about 7 ° at 5kHz).

381 Rotary pole pairs: Set according to the rotary nameplate (1-24). It should be noted that if the number of motor pole pairs is P_motor and the number of rotary pole pairs is P_res, then P_motor/P_res must be integers, otherwise the mechanical absolute angle cannot be correctly resolved.

6.2 Offset Calibration Process

The offset parameter 382 (range -360 ° to+360 °) determines the phase relationship of the stator current vector relative to the rotor magnetic poles. Incorrect offset can cause the motor to fail to start, experience severe vibration, or overcurrent. The standard calibration steps are as follows:

Safety preparation: Release the load (disconnect the coupling), release the mechanical brake, set the upper limit of the frequency converter output frequency (417 switch frequency limit) to a low value (such as 5Hz), and set the current limit (728) to 10% of the rated current of the motor to prevent accidental runaway.

Check the rotation direction of the rotary transformer: manually rotate the motor shaft and observe the actual value of 219. Check the positive and negative of frequency sensor 2. If the displayed symbol is opposite to the direction of rotation, exchange the SIN+and SIN - connections of X410A.

Trial operation: Given a small positive speed reference (e.g. 2Hz), enable the frequency converter. Observe whether the motor rotates smoothly.

If the motor does not rotate or only shakes slightly: check whether the number of pole pairs (373) of the motor matches the number of pole pairs (381) of the rotary converter. If matched, power off and exchange any two-phase motor wires (such as U, V), as the direction of the motor magnetic field may be opposite to the direction of the rotation.

If the motor accelerates until the overclocking alarm (F1100) is triggered, it indicates that the offset difference is about 180 °. At this point, increase the 382 offset by 180 °/Pmotor (number of motor poles) and test drive again.

Fine adjustment: When the motor can stabilize at a given speed, fine tune the offset value online. Observing the actual value of 235 excitation forming voltage, this value should approach 0. If it is positive, increase the offset; If it is negative, reduce the offset. Step 2.5 ° each time until the absolute value of the excitation voltage is minimized. It is best to repeat this step for verification at 50% of the rated frequency.

Restore limiting: After tuning, restore 417 and 728 to their normal application values and perform a "SETUP" guided debugging (if used for the first time) to ensure that the current loop parameters match the transformer.

6.3 Selection of Speed Source

Parameter 766 determines the feedback source for the speed closed-loop based on the actual speed source. The default basic setting is "1- Speed Sensor 1" (i.e. the inverter body comes with an encoder or Hall sensor). If a rotary transformer is required as the main feedback, it should be set as "2- Speed Sensor 2".

Application of Repetitive Frequency Output (EM-RFOUT)

This output converts the rotated angle signal into differential orthogonal pulses, generating a fixed 1024 A/B pulses per revolution (i.e. 4096 lines after 4th multiplication), and outputs a zero position reference signal (R+/R -). This function facilitates the transmission of rotary signals to external PLCs, motion controllers, or synchronization cards, avoiding the need to purchase expensive third-party conversion modules.

In terms of electrical parameters, the output is at RS-422 level (maximum 5V), with overload and short circuit protection, and a maximum output frequency of 512kHz. When wiring, attention should be paid to terminal matching (usually a 120 Ω resistor), and the recommended cable length should not exceed 50 meters to ensure signal integrity.

Parameter List and Fault Diagnosis

8.1 Summary of Key Parameters

Parameter number name range description

219 frequency sensor 2 0.0~999.99Hz rotation actual frequency (proportional to speed)

220 speed sensor 2 0-60000rpm converted speed

253 Analog Input EM-SINA-100~+100% Current Input Percentage

380 Rotary Transformer Excitation Frequency Selection 5/10/20kHz

381 rotation pole pairs set from 1 to 24

382 offset angle -360.0~360.0 ° phase compensation

560 tolerance with 0-25% zero crossing dead zone

561 filtering time constant 0-5000ms optional range

562 analog input working mode 1/11/21/101 feature transformation

563 Error/Warning Behavior 0-3 Under Voltage Response

564-567 feature points X1/Y1/X2/Y2 ± 100% linear mapping

568 adjustment mode 0/1/2 calibration

766 actual speed source 1/2 feedback selection

8.2 Common fault codes

F1421: Rotation synchronization failed. Check whether the rotary signal is interfered with and whether the grounding of the shielding layer is reliable.

F1422: Counting error. Usually caused by insufficient signal amplitude or poor cable contact, the peak voltage measured for SIN/COS should be ≥ 2V (effective value).

F1423: Extreme logarithmic mismatch. Verify if the ratio of motor pole pairs (373) to variable pole pairs (381) is an integer.

F1424: Open circuit. Check if REF+/-, SIN+/-, COS+/- are disconnected.

If there are unlisted internal faults, it is recommended to contact Bonfiglioli technical support and attach a fault record.

Engineering Practice Suggestions

Grounding strategy: The main ground of the frequency converter, the shielding layer of the rotary transformer, and the module ground are grounded at one point in a star shape to avoid the formation of a ground loop.

Cable selection: It is recommended to use twisted pair shielded wire (such as Belden 8770) for the rotary signal line, with a cross-sectional area of 0.25-0.5mm ².

First power on: Measure whether the excitation voltage (REF terminal) is about 4Vrms without motor load, and confirm that the module excitation circuit is normal.

Backup parameters: After debugging, be sure to save all parameters (including those related to expansion modules) to external storage through the operation panel or software for quick recovery in the future.