Mark III Subsea Multiplex Control Pod | SLB

Mark III

Subsea multiplex control pod

Installation of a control pod used in our MUX systems being lowered into the ocean.
Installation of a control pod used in our MUX systems being lowered into the ocean.

The Mark III subsea multiplex (MUX) control pod consists of three major components.

  • Multiplex: The MUX uses pressure-compensated dielectric-filled chambers in the solenoids and transducers rather than 1-atm chambers. The modular design of the solenoid chambers, transducer chambers, and pilot accumulators provides additional barriers to seawater. The MUX is engineered for simplified maintenance of the solenoid valves. Rechargeable batteries for automatic functionality reduces battery replacement.
  • Subsea electronics module (SEM): The SEM has fewer cards and less wiring, providing increased functionality in a smaller size. The repackaged electronics improve heat dissipation. The SEM uses computerized driver modules, eliminating the pie connectors seen in previous-generation control pods.
  • Control panel: The control panel replaces hard-wire push-button panels with electronic, full-color touchscreens. Multiple screens display comprehensive information, including functions and alarms. Updated programming with enhanced graphics allows more-intuitive, user-friendly visual indicators. An upgraded communication system utilizing Ethernet technology via fiber optics provides more robust network management.


  • Touchscreen control panels with enhanced graphics and upgraded communication system
  • SEM with fewer cards, less wiring, and computerized driver modules
  • Solenoids and transducers with pressure-compensated dielectric-filled chambers
  • Power and communication signal that simultaneously and independently transmits to the SEM and riser control box
MARK III Subsea Multiplex Control Pod 3D Model