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PDIM (Power Data Interface Module)

Surface power and real-time data acquisition for Sea-Bird CTDs and SBE 33 Deck Unit; two-way communication over single- or multi-conductor sea cable and ample power for auxiliary sensors.

The Power and Data Interface Module (PDIM) to provides power and real-time data acquisition for an SBE 19, 19plus, 19plus V2, 25, 25plus, or 49 CTD, or SBE 50 Pressure Sensor when connected to an SBE 33 deck unit. The SBE 33 remains at the surface while the PDIM is installed on or near the CTD (CTD refers to the listed CTDs as well as the SBE 50 Pressure Sensor). The system allows for two-way communication for the CTD over a single- or multi-conductor sea cable, and provides ample power for auxiliary sensors that may not otherwise be supportable by a battery-powered CTD.


Note when using SBE 50: Seasave does not support this system; real-time data can be viewed in Seaterm (terminal program). NMEA and/or Surface PAR data (if applicable) is output as raw data.
  • Surface power and real-time data acquisition for Sea-Bird CTDs; two-way communication over single- or multi-conductor sea cable to a SBE 33 Deck Unit, and ample power for auxiliary sensors integrated with the CTD.
  • PDIM’s aluminum housing rated to 6800 m.
  • Seasoft© V2 Windows software package (setup, real-time data acquisition, data processing).
  • Five-year limited warranty.


  • XSG or wet-pluggable MCBH connectors on PDIM and included cables.
Cable Compatibility Single / multi-core armored cable up to 10 km long with inner core resistance up to 350 ohms and armor used as return
Auxiliary Sensor Power Approximately 1 Amp, in addition to CTD power, is available at CTD for support of auxiliary sensors
Weight PDIM: 3.6 kg in air; 1.6 kg in water



 1. DPSK = differential phase shift keyed, FSK = frequency shift keyed.
 2. Seasave also supports acquisition of data from a NMEA device connected directly to the computer.


The list below includes (as applicable) the current product brochure, manual, and quick guide; software manual(s); and application notes.

For older SBE 36 - PDIM product manuals, organized by instrument firmware version, click here.

Title Type Publication Date PDF File
SBE 33 Manual Product Manual Monday, July 31, 2017 PDF icon 33_017.pdf
Family . Housing Connectors
PDIM . 1 – 6800 m (aluminum) 1 – XSG
      2 – MCBH

Example: PDIM.11 is a PDIM with 6800 m housing and XSG connectors. See table below for description of each selection:


Underwater Power/Data Interface Module - accessory for SBE 19/19plus/19plusV2/25/25plus CTDs. Converts surface power for use by CTD and provides two-way communication interface between CTD and Deck Unit via single-conductor armored cables up to 10,000 meters long. Includes Seasoft software and complete documentation. Requires use of SBE 33 or SBE 36 Deck Unit - ordered separately. Does not include interface cables or mounting hardware – ordered separately.

PDIM is required to interface SBE 36 Deck Unit with CTD. PDIM housing is anodized aluminum, & is rated to 6800 m. PDIM order includes sea cable extension cable & pigtail cable, dummy plugs, & jackscrew kit. To order PDIM mount kit & CTD interface cable, see SBE 36 Accessories & Spares above.

Note: PDIM can also be used with SBE 33 Carousel Deck Unit (when used without an SBE 32 Carousel Water Sampler), to provide same functionality as when used with SBE 36 Deck Unit.


PDIM.11 XSG connectors PDIM connector type (XSG or wet-pluggable MCBH) must match CTD connector type. Wet-pluggable connectors provide easy connectability in damp (e.g., rolling, slippery deck) or cold environments (XSG connectors may not seal well in extreme cold; we recommend connecting cables in warm ship’s lab rather than on deck for these conditions). Wet-pluggable connectors are not meant for literally plugging cables in submerged underwater; both our XSG connectors & wet-pluggable connectors must be mated in air.
PDIM.12 Wet-pluggable MCBH connectors
PDIM Spares & Accessories
17088 PDIM to SBE 19/25 cable, XSG connectors, 1.1 m (DN 30567) Connects PDIM to SBE 19, 19plus, 19plus V2, 25, 25plus, or 49 CTD, or SBE 50 Pressure Sensor (SBE 50 with 4-pin connector):
  • 17088 for PDIM & CTD with XSG connectors
  • 171792 for PDIM & CTD with wet-pluggable connectors
171792 PDIM to SBE 19/25 cable, Wet-pluggable connectors, 1.1 m (DN 32810)
50219 PDIM to SBE 19/25 cable, XSG connectors, 1.1 m (DN 30567) PDIM is either mounted to CTD main housing or to CTD cage, depending on number, size, & mounting requirements of auxiliary sensors included in system. Sea-Bird engineering determines appropriate mounting when written quote is requested. For preliminary cost estimate, assume more expensive mounting option (50219).
50154 Mounting hardware kit - PDIM or AFM (clamp on housing)


  • 80915 To PDIM (with XSG connector) (test sea cable), 10 m, DN 31314
  • 801363 To PDIM (with Wet-pluggable connector) (test sea cable), 2.4 m, DN 32695D
  • 17088 PDIM to SBE 19/25, XSG connectors, 1.1 m, DN 30567
  • 171792 PDIM to SBE 19/25, Wet-pluggable connectors, 1.1 m, DN 32810

Mount Kits

  • 50219 Mounting block set for PDIM (bolt to cage)
  • 50154 Mounting hardware kit - PDIM or AFM (clamp on CTD housing)