Application Scenarios

In an automotive welding line using an IRB 6640​ robot, precise repeatability of the welding gun position is critical. If the robot loses its position reference (e.g., due to a power failure or battery depletion), it would require a lengthy recalibration and homing sequence, halting production. The SMB3HAC048550-001​ board in the robot’s base or cabinet continuously tracks the exact multi-turn position of each axis motor. Even after a power cycle, the board’s battery-backed memory ensures the controller knows the robot’s absolute position, allowing it to resume welding within ±0.1 mm accuracy immediately, minimizing downtime.

 

Parameter

Main Parameters	Value/Description
Product Model​	SMB3HAC048550-001​
Manufacturer​	ABB
Part Number​	3HAC048550-001
Product Category​	Serial Measurement Board (SMB) / Robot Axis Board
Primary Function​	Resolver/Encoder Interface & Absolute Position Storage
Compatible Robots​	IRB 6640, IRB 6650, IRB 6660, IRB 7600 series (and other large 6-axis robots)
Feedback Type​	Resolver (Analog Sin/Cos) to Digital Conversion
Battery Backup​	Yes (Typically 3.6V Lithium, e.g., ER3A)
Communication Interface​	High-Speed Serial (DriveBus/Resolver Bus) to Axis Computer
Typical Fault Codes​	38101 (SMB Comm Fault), 38213 (Battery Low)
Mounting Location​	Inside Robot Base or Control Cabinet

 

 

Technical Principles and Innovative Values

• Innovation Point 1: Absolute Position Memory System.​ Unlike incremental encoders that lose position on power loss, the SMB board, in conjunction with ABB’s single-turn absolute motors, maintains a multi-turn count. The board’s non-volatile memory (powered by a backup battery) stores the revolution data, eliminating the need for mechanical homing switches and saving valuable production time during restarts.
• Innovation Point 2: High-Resolution Resolver Conversion.​ The board employs precision analog-to-digital converters (ADCs) and specialized ASICs to process the raw sine/cosine signals from the motor resolvers. This allows it to calculate the motor’s angular position with extremely high resolution (often exceeding 16 bits), which is fundamental to the robot’s sub-millimeter repeatability.
• Innovation Point 3: Multi-Axis Signal Consolidation.​ A single SMB board typically handles the feedback for multiple robot axes (e.g., 3 or 6 axes) through a serial communication scheme. This reduces the amount of wiring needed between the robot arm and the controller compared to parallel encoder systems, improving reliability and simplifying cable harness design.

 

Application Cases and Industry Value

• Case 1: Automotive Body Shop Recovery.​ A major automotive plant experienced a complete power outage, causing all 120 welding robots to lose power. Robots without a functioning SMB battery required a 45-minute manual recalibration per robot. However, the 80 robots equipped with properly maintained SMB3HAC048550-001​ boards (with good batteries) resumed production immediately after power restoration, saving over 60 hours of potential line downtime and preventing a significant production loss.
• Case 2: Foundry Robot Reliability Upgrade.​ A foundry using IRB 7600 robots for heavy casting handling was plagued by frequent resolver cable failures due to the harsh environment, leading to “Resolver Error” faults. By upgrading to a refurbished and tested SMB3HAC048550-001​ board with enhanced signal filtering capabilities, the plant reduced false-positive resolver alarms caused by electrical noise, increasing the Mean Time Between Failures (MTBF) for the robot’s drive system by 30%.