Phoenix Contact INTERBUS IBS Modules: IBS RT 24 DIO 16/16-T

Technical Dossier

Product Details And Specifications

Phoenix Contact INTERBUS (IBS) Series: Comprehensive Module Range and Technical Overview

The Phoenix Contact INTERBUS (IBS) series represents one of the most widely deployed remote I/O and fieldbus communication platforms in global heavy industry. Installed across petrochemical complexes, nuclear power facilities, offshore platforms, and continuous-process refineries, the IBS architecture operates on a ring-topology serial bus protocol standardized under IEC 61158. Its deterministic data transmission, fault-isolation capability, and modular backplane design made it the preferred distributed I/O solution for process automation engineers throughout the 1990s and 2000s. The IBS RT 24 DIO 16/16-T is a representative remote terminal module providing 16 digital inputs and 16 digital outputs at 24 VDC logic level, designed for direct rail mounting in distributed control cabinets.

The Evolution of INTERBUS (IBS) Architecture

INTERBUS was introduced by Phoenix Contact in 1987 as a proprietary serial fieldbus, later ratified as IEC 61158 Type 8. The protocol uses a shift-register principle over a single ring cable, enabling deterministic cycle times independent of node count. Early generations (IBS ST 24 BK series) used parallel backplane wiring; subsequent inline (IL) and remote terminal (RT) generations consolidated wiring into compact DIN-rail modules with integrated bus connectors. The transition from INTERBUS to PROFINET and EtherNet/IP began around 2008, with Phoenix Contact releasing gateway bridges (IBS S7 300 DSC/I-T) to allow legacy IBS segments to coexist with modern Ethernet-based controllers. As of 2026, the full IBS series is in the mature/end-of-life phase. Phoenix Contact no longer manufactures new IBS remote terminal modules; however, installed base volumes in long-lifecycle industries (nuclear, refining, water treatment) sustain strong demand for certified replacement units and tested surplus stock.

INTERBUS (IBS) Full Catalog & Functionalities — SKU List

The following SKUs represent verified, commonly sourced modules within the Phoenix Contact INTERBUS ecosystem. Each entry reflects a distinct functional role within the IBS ring topology.

Remote Terminal / Digital I/O Modules

• IBS RT 24 DIO 16/16-T: 16 DI + 16 DO, 24 VDC, remote terminal, DIN rail mount
• IBS RT 24 DIO 8/8-T: 8 DI + 8 DO, 24 VDC, compact remote terminal for space-constrained panels
• IBS RT 24 DI 16-T: 16-channel digital input only remote terminal, 24 VDC sink/source
• IBS RT 24 DO 16-T: 16-channel digital output only remote terminal, 24 VDC, 0.5 A per channel
• IBS ST 24 BK-T: INTERBUS ST bus coupler/terminal block, 24 VDC, inline segment head
• IBS ST 24 DI 8-T: 8-channel digital input inline terminal, 24 VDC, IBS ST segment
• IBS ST 24 DO 8-T: 8-channel digital output inline terminal, 24 VDC, 0.5 A, IBS ST segment

Analog I/O Modules

• IBS RT 24 AI 4/SF: 4-channel analog input, 0–10 V / 4–20 mA selectable, 12-bit resolution
• IBS RT 24 AO 4/SF: 4-channel analog output, 0–10 V / 4–20 mA, 12-bit, remote terminal
• IBS ST 24 AI 4/SF: 4-channel analog input inline terminal, IBS ST segment compatible

Communication & Gateway Modules

• IBS S7 300 DSC/I-T: INTERBUS master for Siemens S7-300 rack, DP/IBS gateway function
• IBS S7 400 DSC/I-T: INTERBUS master for Siemens S7-400 rack, high-speed ring controller
• IBS PCI SC/I-T: PCI bus INTERBUS master card for PC-based control systems
• IBS CBL EF 1,5: INTERBUS remote bus cable, 1.5 mm², shielded, standard ring segment wiring

Power Supply & Segment Modules

• IBS IP 24 PWR/ZF-T: 24 VDC segment power supply module, integrated into IBS inline segment
• IBS ST 24 PWR/XC-T: Extended current power terminal for IBS ST segments, 4 A output

Sourcing Hard-to-Find & Obsolete INTERBUS (IBS) Parts

Quality Control for the INTERBUS (IBS) Range

INTERBUS modules present specific test challenges due to their ring-topology bus dependency: a single faulty node can disrupt the entire segment. DriveKNMS applies a multi-stage verification protocol for all IBS units. Each module undergoes visual inspection for backplane connector pin integrity, capacitor condition, and conformal coating status. Functional testing is performed by inserting the module into an active IBS ring segment driven by a Phoenix Contact IBS master controller, verifying correct device identification, process data exchange, and diagnostic register response. Digital I/O modules such as the IBS RT 24 DIO 16/16-T are tested under load conditions: all input channels are stimulated with 24 VDC signals and all output channels are verified against resistive loads at rated current. Analog modules are calibrated against a traceable reference source. Modules that pass all test stages are issued a DriveKNMS inspection record and shipped with ESD-protective packaging.