Underwater Servo Motors

The actuator supports RS422 (RS485 full duplex on 4 wires) and RS232 serial communication protocols at 19200 baud, 8, N, 1. Communication parameters are stored in EEPROM and are configurable. Status messages are broadcast at 10 Hz by default and can be adjusted to suit system integration requirements.

The actuator uses an absolute multi-turn encoder with 30-bit total resolution — 14-bit single-turn (16,383 counts/turn) plus a 16-bit turns counter. Because it is an absolute encoder, position information is retained across power cycles without requiring a homing sequence, which is critical for reliable subsea robotic operations.

The actuator delivers a nominal continuous torque of 19 ft. lbf (27 Nm) with a maximum continuous current draw of 2.9 A. At the standard 238:1 gear ratio, the maximum output shaft speed is 30 RPM. Position precision at the output shaft is 0.1 degrees, enabling fine-resolution control for subsea manipulators.

The actuator uses an MCBH8M SubConn 8-pin underwater connector, which is an industry-standard wet-mateable connector widely used in subsea and ROV applications. This connector provides reliable electrical connectivity in submerged environments and is compatible with standard ROV umbilical and tether wiring systems.

The actuator supports two primary operating modes: continuous spin (jog) mode for unrestricted rotation, and precise position control mode with 0.1-degree resolution at the output shaft. Two software-configurable virtual travel limit switches provide added operational safety. Mode parameters are stored in EEPROM for persistence across power cycles.

These motors are designed for underwater remotely operated vehicles (ROVs), deep-sea robotic manipulators, subsea valve and equipment actuation, ocean research instrumentation, and underwater inspection and cleaning systems. Their self-contained electronics and depth rating of 3000 msw make them applicable across offshore energy, marine research, and municipal water infrastructure sectors.