UART Bus Servo 25KG 1111

1. Features

Integrated design: brushed motor, reducer, 12‑bit magnetic absolute encoder, and controller
UART/TTL half‑duplex protocol up to 1 Mbps
Resolution 4096 counts/360° (0.088°); min control step 0.1°
Control range: ±180° (single‑turn) or ±368,640° / ±1024 turns (multi‑turn)
Power‑off position retention
Trapezoidal accel/decel trajectory for smooth motion
Auto power threshold detection with adaptive reduction
Three stop modes: Free / Lock / Damping
Five protections: temperature / voltage / stall / power / current
PC configuration tool; firmware upgradable

2. Model definition

Appearance	R：Dual-shaft	H：Single-shaft
Motor type	X：Brushless	P：Coreless	A/L：Cored
Dimension	6：31.5×21×27.6mm	8：40×40×20mm	18：63×34×47mm
Protocols	U：UART/TTL	R：RS-485	C：CAN
Voltage	[-]：7.4V	H：12V	W：24V
Position Sensor	[-]：Potentiometer	M:12-bit magnetic absolute encoder

Models available for order - RA8-U25(H)-M|HA8-U25(H)-M

3. Specifications

3.1 Basic Specifications

Item	Specification
Input Voltage	6.0-8.4V \| 9.0–12.6 V
Resolution	2048/360° (0.176°)
Baud Rate	9,600 bps–1 Mbps
Gear Material	All-metal copper-aluminum composite

3.2 Characteristics

Item	Specifications（7.4V\|12V）
Max Stall Torque	2.54 N·m (25 kg·cm)
Max Continuous Torque	0.88 N·m (9 kg·cm)
No‑load Speed	51 rpm (0.198 sec@60°)
Peak Current	3 A

3.3 Performance Graph

3.4 Overload Graph

4. Drawings and Installation Instructions

4.1 CAD Dimensional Drawing

4.2 Interface Definition

4.3 Wiring Diagram

Series Connection
Parallel Connection

4.4 Installation Instruction

Single-shaft
Dual-shaft

5. Development & Compatibility

The bus servo series adopts a unified hardware platform.

6. Protections

All protection parameters can be set and modified by our PC configuration tool.
The status flag bits are defined as follows: 1 represents Protection triggered，0 represents normal operation.

Warning

Modification towards any protection parameters may cause damage to the production.

7. Control & Modes

7.2 Communication Format

Transmit Packet Format
Response Packet Format

7.6 Single-Turn Position Control

7.7 Multi-Turn Position Control

Multi-turn Position Reset
Power-off Position Retention

8. Configuration Parameters

Number	Parameter Name	Write	Unit	Default
34	Servo ID	●	-	1
36	Baud Rate	●	bps	1Mbps
41	Protection Temp	●	ADC	70°C