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: