KOLLMORGEN Digifas-7200 Digital Servo Amplifier Application Guide

Digifas ™  The 7200 series digital servo amplifier is a key driving component in the field of industrial automation, designed specifically for controlling synchronous servo motors. It is widely used in high-precision motion control systems such as machine tools, packaging machinery, and printing equipment. This article is based on the official product manual, combined with technical details and practical applications, to comprehensively analyze the functional characteristics, installation specifications, parameter configuration, and maintenance points of this series of amplifiers, aiming to provide systematic reference materials for engineers and technicians.

Product Overview and Series Classification

Digifas ™  The 7200 series adopts a fully digital design and supports direct connection to 400V three-phase industrial power grids without the need for additional transformers. It has the characteristics of compact structure, fast response, and high control accuracy. This series offers multiple versions to meet different control requirements:

Standard version: Equipped with simulated speed setting input, incremental position output, and controllable motor holding braking function, suitable for systems with external position control.

BIT CONNECT version: Integrated PLC interface, connected to a simple controller through 10 I/O channels, supports internal storage of motion datasets, and achieves position control function.

PULSE CONNECT version: Provides pulse direction interface, can be used as a stepper motor controller or slave station, supports cascaded position control.

PROFIBUS CONNECT version: compatible with the PROFIBUS-DP protocol and suitable for integrated bus control systems.

CAN CONNECT version: Supports CAN bus communication and is suitable for distributed motion control networks.

Each version offers optional options, such as the "- IL -" controllable torque limiting module and the "- BV -" forced air cooling module, to expand application flexibility.

Technical specifications and design features

2.1 Power Supply and Output Characteristics

Digifas ™  The 7200 series directly supports 3 × 80-400V AC power input, with a rated intermediate circuit voltage of 560V DC. The output current range covers 1.5A to 6A (effective value), and the peak current can reach twice the rated value. The IGBT output stage adopts a switching frequency of 8.33kHz, and the current controller bandwidth reaches 1kHz, ensuring fast dynamic response.

2.2 Control Interface and Signal Processing

The amplifier is equipped with differential analog setting input (± 10V, 14 bit resolution) and supports speed or torque control modes. All digital control inputs are isolated by optocouplers and compatible with 24V PLC levels. The system provides multiple grounding references (AGND, DGND, XGND, PGND) to achieve signal isolation and anti-interference.

2.3 Braking and Energy Feedback Processing

The built-in braking circuit is used to process the feedback energy of the motor, and automatically connects to the braking resistor when the intermediate circuit voltage exceeds 720V. The power of the braking resistor varies depending on the model (75W or 140W), and supports parallel connection of multiple amplifier intermediate circuits to share braking energy. In addition, the amplifier can directly control the 24V motor to maintain braking and has braking timing management function.

2.4 Environmental and Mechanical Requirements

The working environment temperature is 0-45 ℃ (rated value), and 45-55 ℃ needs to be downgraded for use. The protection level is IP20, suitable for installation in electrical cabinets. During installation, it is necessary to ensure vertical placement and leave sufficient space for heat dissipation. Long cables (>25m) require an external motor reactor (such as 3YL-06) to suppress capacitive reactive current.

Installation and wiring specifications

3.1 Safety Notice

Installation and commissioning must be carried out by professionals with electrical qualifications. Before operation, ensure that the power is completely disconnected and wait for at least 2 minutes after the power is cut off. Only when the voltage of the intermediate circuit is below 40V can the terminals be contacted. The amplifier contains static sensitive components, and the operator needs to take anti-static measures.

3.2 EMC and Grounding Design

To comply with the requirements of the EC EMC Directive (89/336/EEC), shielded cables must be used and large-area low impedance grounding must be implemented. The manual recommends using shielded terminal clips, metalized connector housings, and grounding motors, filters, control cabinet mounting plates, etc. to the same potential. The power line and signal line should be laid separately, with a recommended spacing of more than 20cm.

3.3 Wiring Examples and Multi Axis Systems

The manual provides standard wiring diagrams for different motor series (6SM27/37/47/57/77 and 6SM45/56), covering connections for main power supply, control signals, encoders, brakes, etc. In a multi axis system, each amplifier can share an intermediate circuit, but it needs to be grounded uniformly and the braking power should be configured reasonably.

Parameter setting and debugging process

4.1 Parameter Classification

Amplifier parameters are divided into the following categories:

General parameters: such as motor pole pairs, language, brake enable, position interface type (ROD/SSI), etc.

Current controller parameters: including effective current, peak current, I ² t threshold, proportional gain, and integration time.

Speed controller parameters: including proportional gain, integration time, set point ramp, limit switch function, phase compensation, etc.

Service functions: such as constant speed, constant current, reciprocating operation and other testing modes.

4.2 Debugging steps

Hardware inspection: Confirm that the motor matches the amplifier and that the wiring conforms to the drawing.

Power on: First connect the 24V auxiliary power supply, then connect the main power supply.

Software connection: Connect to the PC through the SubD9 interface and run the BS7200 operating software.

Parameter initialization: Set the number of poles, encoder type, braking parameters, etc. based on the motor model.

Controller tuning: Gradually adjust the parameters of the current loop and speed loop to optimize dynamic response.

Functional testing: Enable service functions such as limit switches and brake control to verify system behavior.

4.3 Status Monitoring and Diagnosis

The amplifier provides real-time status display, including:

Internal temperature, heat sink temperature

Intermediate circuit voltage, actual output current

Braking power, motor speed, mechanical angle

Run time statistics

Fault information is prompted through red LED and PC interface. Common faults include: undervoltage/overvoltage, output stage fault, brake short circuit, encoder error, etc. All faults will trigger the BTB relay to disconnect, cutting off the system enable.

Optional features and interface extensions

5.1 Incremental Encoder and SSI Interface

The standard version provides incremental (ROD) or SSI absolute value position output. ROD output supports 500-1024 pulses per revolution, with adjustable zero position; The SSI interface supports 12 bit single loop data, and the clock frequency can be selected from 200kHz or 1.5MHz.

5.2 Controllable torque limit (- IL - option)

This external module limits motor torque in real-time by simulating voltage (0-10V), making it suitable for scenarios such as tension control and flexible assembly. The module integrates a speed controller, which can accept two speed setting inputs and has the function of enabling and interlocking with the limit.

5.3 PC Operating Interface

Through BS7200 software, users can fully access parameter tables, monitor curves in real-time, and save/load configurations. The software supports MS-DOS system and requires at least 80386 processor, 1MB memory, and VGA display.

Maintenance, fault diagnosis, and disposal

6.1 Daily Maintenance

The amplifier is designed to be maintenance free, and unauthorized opening of the casing is prohibited. Surface cleaning can be done with isopropanol and should not be soaked or sprayed. After long-term storage (>1 year), the intermediate circuit capacitors need to undergo "reformation" treatment (by passing single-phase 230V AC for 30 minutes).

6.2 Common troubleshooting

The manual provides fault tree analysis, such as:

Communication failure: Check cable model, interface selection, and PC grounding.

Overvoltage fault: increase braking power, shorten deceleration ramp, parallel intermediate circuit.

Brake malfunction: Check for a short circuit in the brake coil or damage to the motor.

Output level fault: Check for motor cable short circuit, grounding or poor heat dissipation.

6.3 Scrapping and Recycling

The amplifier can be disassembled into components such as aluminum heat sinks, steel shells, electronic boards, etc., and should be disposed of by certified recycling companies to comply with environmental regulations.