Ezi-SPEED Modbus-RTU

1. RS-485 based Modbus-RTU Control
Ezi-SPEED Modbus-RTU supports the Modbus-RTU protocol based on RS-485 communication, allowing for the construction of various control systems utilizing RS-485 in addition to input and output signalbased control. Modbus operates in a single master/multi-slave mode, where only the master can send commands, and each slave responds after executing the commands.


A single master controller can connect with up to 31 slaves (drives). The master controller can send commands to either a single slave or multiple slaves simultaneously
2. BLDC Motor Unit
General DC motors require regular maintenance as they use brushes and a commutator to rotate. In contrast BLDC (Brushless DC) motors have a long lifespan and excellent maintenance characteristics because they operate through a circuit composed of semiconductors without mechanical contacts. They incorporate permanent magnets in the rotor to enhance efficiency and maintain consistent torque characteristics across all speed ranges by automatically controlling motor current. Additionally, they utilize Hall IC for feedback control, allowing precise speed regulation from low to high speed.

[ Control Block Diagram ]


The BLDC motor has a constant torque from low speed to rated rotational speed. Therefore, it rotates at a stable speed no matter how the load changes in size. BLDC motor has continuous duty region (①) and limited duty region (②). Limited region can be used as the acceleration torque when starting the inertial stuff. However, in this region, if it’s used for more than 40 seconds, overload protection is protected and the motor stops.

[ Example of Torque Characteristics According to Speed of BLDC Motor ]

3. High Precision Speed Control(Speed Regulation 0.2%)
Ezi-SPEED compares the setting speed with the speed feedback signals from the motor at all time, and adjusts the motor current using vector control algorithm. So, even if the load changes, stable rotation is maintained from low speed to high speed. Inverter controlled AC induction motor does not perform feedback control, so the speed will be reduced significantly when load increases. Ezi-SPEED is recommended for applications that require stable speed.

Ezi-SPEED 120W



Inverter + AC Induction Motor 100W

* Load Factor: 95%
* Setting Speed: 1,500r/min
* Resolution of External Encoder for Measuring Velocity Ripple: 32,000P/R
4. Wide Speed Control Range(Speed Ratio : 1:80)
Ezi-SPEED has wide speed control range compared to AC induction motor with inverter. Because torque is not restricted at low speed, Ezi-SPEED is recommended for application that requires stable torque over from low to high speed.
Product Speed Control Range[r/min] Speed Ratio
Ezi-SPEED 50 ~ 4,000 1:80
Inverter + AC Induction Motor 200 ~ 2,400 1:12
* Speed range of Inverter + AC Induction Motor varies depending on model type.
5. Compact / Light Weight / High Power / High Efficiency
Unlike AC induction motors, BLDC motors use permanent magnets in the rotor so that it could prevent secondary loss from rotor. Therefore, BLDC motors has higher efficiency than inverter-controlled AC induction motor so that customers can save energy.


● Comparison of motor temperature after 4 hours continuous operation when load factor is 100% and Setting speed is 1,500 r/min.
6. Torque Limit Function
Ezi-SPEED provides this function to control the torque by limiting the current flowing through the motor. Torque limit function can be used to prevent excessive force.
7. Load Holding Function
Load holding function can be used for an electrical retention brake at stop without the need for a mechanical brake. So, this function is suitable for applications that perform work while stopping the transportation conveyors.
8. Operation by External I/O
A controller, such as a PLC, can perform operations such as starting, stopping, changing the direction of rotation, and multi-speed operation. Additionally, the speed can be adjusted by applying external DC voltage or by connecting a potentiometer.
9. 16-Speed Settings
16-speed operation can be done by setting operation data No. 0 to No. 15. Operation data can be configured using Ezi-SPEED Setting program or through RS-485 communication.
10. Ezi-SPEED Setting program
Ezi-SPEED Modbus-RTU can perform various functions using the separately provided Ezi-SPEED Setting program.
• Parameter Setting Function: Easily modify and save various parameters.
• Monitoring Function: Easily monitor the internal status of the drive and motor, including speed, load factor, I/O signals, alarms, and warnings.
• Testing Function: Easily test whether the drive and motor are operating correctly.
11. Protection Function
• Ezi-SPEED detects abnormal situations like overload, over voltage etc. When this happens, the operation is stopped and alarm is displayed.
• A regenerative resistor can be used when the deceleration time is short or when the large inertia load is used. Also the protection function can be activated for the excessive external force acting on the motor shaft.