ABB RTAC-01 Pulse Encoder Interface Module

The ABB RTAC-01 Pulse Encoder Interface Module is a high-performance expansion module specifically designed for the ABB ACS 800 series of variable frequency drives (VFDs). It enables reliable connection between a digital pulse encoder and the drive, making it suitable for industrial applications requiring precise motor speed or position (angle) feedback, such as high-precision drive systems, positioning control, synchronization control, and closed-loop speed control. The RTAC-01 module offers flexible power supply options, multiple encoder signal connection methods, and robust diagnostic capabilities, making it a key component for enhancing the control accuracy and reliability of drive systems.

Designed to meet the demanding requirements of industrial environments, the module features good electromagnetic compatibility (EMC), electrical isolation, and high environmental adaptability. It is fully compatible with ACS 800 Standard Application Program version ASXR7000 or later. Its compact design and convenient installation method allow users to easily integrate it into existing drive systems for high-quality acquisition and processing of encoder signals.

II. Product Features

1. High-Precision Signal Interface

• Supports three-channel (A, B, Z) differential or single-ended encoder signal input.

• Maximum signal frequency of 200 kHz, meeting the needs of high-speed, high-precision applications.

• Speed feedback resolution up to 0.00305% (15-bit), with speed feedback accuracy of 50 ppm.

2. Flexible Power Supply Configuration

• Built-in switchable 15 V DC or 24 V DC encoder power supply with a maximum output power of 5 W.

• Supports external power supply for encoders with higher power requirements.

• The power output features short-circuit protection.

3. Strong Compatibility and Expandability

• Compatible with four common encoder output types: differential push-pull, single-ended push-pull, open collector (sinking), and open emitter (sourcing).

• Provides detailed wiring diagrams to support connections for different output types.

• Can be mounted externally on a DIN rail using the AIMA-01 I/O Module Adapter, increasing system I/O configuration flexibility.

4. Comprehensive Diagnostics and Status Indication

• The module panel is equipped with three diagnostic LEDs:

• CHA (Green) & CHB (Green): Indicate signal activity status on Channel A and Channel B, respectively.

• WD/INIT (Yellow): Indicates module initialization and communication status.

• Supports node address setting (for external adapter installation), facilitating multi-module system configuration.

5. Excellent Reliability and Safety

• All input channels are electrically isolated from the logic circuit, power supply, and ground, withstanding a test voltage of 1.5 kV AC for 1 minute.

• Complies with EMC standards EN 50081-2 and EN 50082-2, ensuring good noise immunity.

• All materials are UL/CSA certified, with an estimated minimum lifetime of 100,000 hours.

6. Easy Installation and Programming

• Can be directly inserted into SLOT 1 or SLOT 2 on the ACS 800 drive's RMIO board and secured with screws for grounding.

• Configured through drive parameters (Parameter Groups 50 and 98), requiring no additional specialized software.

• Provides clear terminal definitions and power consumption calculation guidance for easy engineering implementation.

  
  

III. Installation and Configuration Guide

1. Pre-Installation Preparation

• Safety First: All electrical installation and maintenance work must be performed by qualified electricians. Before any work, ensure the main power is disconnected, wait at least 5 minutes for the DC link capacitors to discharge, and verify the drive is completely discharged.

• Tools and Documentation: Prepare standard installation tools and have the relevant ACS 800 drive manuals (e.g., Hardware Manual, Firmware Manual) on hand for important information not covered in this manual.

• Compatibility Check: Ensure the drive's ACS 800 Standard Application Program is version ASXR7000 or later.

2. Module Installation Steps

• Slot Installation: Carefully insert the RTAC-01 module into the slot marked SLOT 1 or SLOT 2 on the RMIO board until the plastic retaining clips lock the module in place.

• Screw Fastening: Secure the module to the stand-offs using the two supplied M3×8 mm screws. Tighten the screws securely. This is essential not only for mechanical fixing but also for grounding the I/O cable shield and connecting the GND signals between the module and the RMIO board, which is crucial for meeting EMC requirements and proper module operation.

• External Adapter Installation: If using the AIMA-01 adapter, mount the module onto the adapter, set a unique Node ID (16–31) via rotary switch S1, and establish communication with the drive via fiber optic cables.

3. Encoder Wiring and Configuration

• Power Selection: Based on the encoder's rated voltage, select 15 V (default, connect terminals 4-5) or 24 V (connect terminals 5-6) output via the jumper on terminal block X1. If using an external power supply, remove this jumper and connect the external supply as shown in Figure 3-1.

• Signal Connection: Connect the encoder's A, B, and Z phase signals correctly to terminal block X2 according to the encoder output type (see manual Figures 3-3 to 3-6). Pay attention to the phase relationship: When the drive runs forward, the A-phase signal should lead the B-phase signal by 90 electrical degrees.

• Shield Handling: The encoder cable shield should be grounded at the RTAC module end (connected to SHLD terminals on X2). If the encoder itself is isolated from the motor and ground, the shield should also be connected to the encoder housing.

• Cabling Recommendation: Encoder cables should be routed away from power cables (e.g., motor cables) and should not run parallel to them to minimize interference.

4. Parameter Setting

• The module's functions are configured via drive parameters, primarily Parameter Group 50 (Encoder Interface) and Parameter Group 98 (Extension Module Configuration).

• Parameters that may need setting include: encoder pulses per revolution, signal type (differential/single-ended), filter settings, zero pulse enable, etc. Refer to the ACS 800 Firmware Manual for specific settings.

IV. Typical Applications and Advantages

1. Application Scenarios

• High-Precision Closed-Loop Speed Control: Used in applications like fans, pumps, and conveyors requiring stable speed, utilizing encoder feedback for more precise speed regulation compared to open-loop V/f control.

• Position Synchronization and Positioning: In equipment like winders, cutters, and material handling systems, using the Z-phase (zero marker) signal for precise homing or multi-axis synchronized operation.

• Servo-like Applications: Coupled with high-performance encoders, enables precise control of torque, speed, and position for high-end equipment like machine tools and robots.

• Replacement of Tachogenerators: Provides a digital speed feedback solution with higher precision and better noise immunity than analog tachogenerators.

2. User Advantages

• Enhanced System Performance: High-precision speed and position feedback significantly improve the dynamic response and control accuracy of the entire drive system.

• Increased Reliability: Differential signal transmission and good EMC design ensure stable and reliable signals in noisy industrial environments.

• Simplified System Design: Modular, plug-and-play design reduces the cost and risk associated with designing custom interface circuits.

• Easier Diagnostics and Maintenance: Clear LED status indicators and diagnostic information accessible via drive parameters simplify troubleshooting.

• Future Expandability: Support for external adapter installation provides flexibility for adding more I/O modules to the system later.

V. Safe Operation and Troubleshooting

1. Key Safe Operation Points

• Work on De-energized Equipment: Any installation, wiring, or maintenance must be performed only after the drive is completely disconnected from power and confirmed to be discharged.

• Qualified Personnel Only: Work should be carried out only by electrical personnel with appropriate qualifications.

• Follow Manuals: Strictly adhere to all safety instructions in this manual and the accompanying drive manuals.

2. Common Troubleshooting

• WD/INIT LED stays ON and does not go out:

• Slot Installation: Check if the 38-pin connector is properly inserted; try cycling the drive power OFF and ON; if the problem persists, there may be a hardware fault – contact an ABB service representative.

• Adapter Installation: Check if the drive is powered; verify the module Node ID setting; check that fiber optic cables are connected correctly (transmitter to receiver), are properly inserted, and are free from dirt or physical damage visually; try new fiber optic cables.

• No Speed Feedback or Incorrect Feedback:

• Check if CHA/CHB LEDs are flashing to confirm signal is present.

• Verify the encoder type matches the wiring diagram.

• Check if the encoder supply voltage is correct.

• Verify settings like encoder pulses per revolution in the drive parameters.

• Use an oscilloscope to check if the phase relationship between A and B signals meets requirements.

• Excessive Signal Noise:

• Check if the encoder cable shield is reliably grounded at the RTAC end.

• Ensure encoder cables are routed separately from power cables and avoid running parallel.

• Check if cable length exceeds the recommended maximum.

VI. Warranty and Support

ABB provides a warranty for the RTAC-01 module covering manufacturing defects. The warranty period is 12 months from the date of delivery, not exceeding 18 months. Extended warranty options may be available with certified start-up services; contact your local ABB distributor for details.

Important Disclaimer: The manufacturer is not liable for damage or failures due to transport, improper unpacking, misuse, abuse, improper installation, abnormal conditions (temperature, dust, corrosives), operation above rated capacities, or for any consequential or incidental damages. Product technical data and specifications are valid at the time of printing; ABB reserves the right to subsequent alterations.