ABB S900 I/O Module – ABB PLC‘s DCS’s Systems
S900 is a remote I/O system for mounting directly in the field and hazardous areas.
S900 provides all input and output modules needed for intrinsically safe field signal connection. The field signals are amplified in every S900 functional module, electrically isolated, and then output via an internal serial bus. A communication interface converts the digitized signals to adapt them to the standardized PROFIBUS DPV1 fieldbus protocol. Supervisory process control systems, DCS or SCADA systems use an intrinsically safe fieldbus to communicate with the communication interface.
A single fieldbus network suffices for configuring the individual fieldbus nodes, for cyclic data exchange, for all acyclic services, and for communication with HART®-compatible field instruments. All functional modules can be replaced easily and quickly in the installation or maintenance phase. The functional modules and the – optionally redundant – communication interfaces of systems placed in Zone 1 can be removed and plugged in while operation is running, without affecting the communication of the remaining modules. Only the primary power for the plug-in type power supply modules requires increased safety EEx-e.
Integrated encapsulated switch-off mechanisms allow for hotswapping, i.e. the power supply units can be replaced without interrupting the primary power. Due to its little space requirements and robust design and its environmentally ruggedized case, the I/O system S900 is the best, cost-saving so
Benefit
- Value for your money: Integrated galvanic isolated barrier function reduces the need for additional barriers
- Simplified maintenance thanks to auto-diagnostics and the availability of diagnostic data via the fieldbus or locally at the S900 I/O station
- Easy configuration using FDT/DTM or GSD files

Application
Ready-made, EExi/ATEX-certified high-grade steel housings and the CB220 Compact Box for assembly in the field provide a wide range of installation options.
Field housings – for wall-mounting in the case of installation in Zone1 with a system approval fully certified in accordance with ATEX. The stainless steel field housing is ready-wired and prepared
for wall-mounting. In addition, screen rails or terminals can be mounted. Together with the field housing, this brings the following advantages:
- Complete design, heat compensation, and documentation by ABB
- Elimination of additional marshalling units
- Thanks to the S900 modules, no external barriers are needed for the field circuits
- Simplified acceptance of the plant with regard to hazardous areas
CB220 compact box – S900 remote I/O in compact form with up to 4 I/O modules for decentralized use in a compact housing. This variant is suitable, for example, for use in applications such as temperature multiplexers and solenoid controls. The CB220 compact box additionally offers the following advantages:
- Compact design
- Easy field assembly
- Decentralized assembly makes it possible to cut down on wiring
Data
Distributed signal acquisition has become more and more accepted in the field of process engineering. With S900 ABB offers an eco-efficient remote I/O system with redundant networking capability.
Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Transmitter power supply, Analog Input 4…20 mA |
S900-AI910N | S900-AI910B | S900-AI910S |
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Transmitter power supply, Analog Input, HART 4…20 mA |
S900-AI930N | S900-AI930B | S900-AI930S |
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Passive Analog Input, HART 0/4…20 mA |
S900-AI931N | S900-AI931B | S900-AI931S |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Analog output 0/4…20 mA |
S900-AO910N | S900-AO910B | S900-AO910S |
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Analog output, isolated 0/4…20 mA isolated outputs channel by channel |
S900-AO920N | S900-AO920B | S900-AO920S |
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Analog output HART 0/4…20 mA |
S900-AO930N | S900-AO930B | S900-AO930S |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Digital Output for I.S. valves (4 channels) |
S900-DO910N | S900-DO910B | S900-DO910S |
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Digital Input or Output input for dry contact or NAMUR initiator output for low power I.S. valves (8 channels) |
S900-DX910N | S900-DX910B | S900-DX910S |
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Relay module for digital signals (6 channels) |
S900-DO930N | none | none |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Pt100, Pt1000, Ni100 in 2-/3-/4-technology thermocouples type B, E, J, K, L, N, R, S, T isolated inputs channel by channel |
S900-AI950N | S900-AI950B | S900-AI950S |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
input for dry contact or NAMUR initiator | S900-DP910N | S900-DP910B | S900-DP910S |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Communication Interface for PROFIBUS DP-V1 |
S900-CI920N | S900-CI920B | S900-CI920S |
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Intrinsically safe PROFIBUS-DP connector | standard connector | S900-BP910S | S900-BP910S |
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Fieldbus isolating repeater
separates an intrinsically safe RS485 fieldbus from a non intrinsically safe
Description | Ex Zone 1 |
RS485 fieldbus without bus termination mounted in DIN railmounted housing with IP20 protection |
S900-BI912S |
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RS485 fieldbus with bus termination mounted in DIN railmounted housing with IP20 protection |
S900-BI913S |
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Fieldbus isolating repeater RS485 / fiber optic ring Master/Slave | S900-BI924S (Master) S900-BI923S (Slave) |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Power supply filter One filter is necessary for powersupply with Catalog No. SA910S |
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S900-BP901S |
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CD-ROM / S900 Software-Tools / Documentation CD-ROM / DTM f0r fieldbus devices CD-ROM / SMART VISION CD-ROM / Fieldbus project tool >>see list 63 |
S900-CD910 | ||
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Field housing, stainless steel (1.43.01) | S900-FH660S-0000 (empty box) | ![]() |
S900-FH660S-xxxx Series (certified, incl. wiring) |
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S900-FH680S-0000 (empty box) | ![]() |
S900-FH680S-xxxx Series (certified, incl. wiring) | |
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Insert labels 320 pcs. |
S900-IL910 | S900-IL910 | S900-IL910 |
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Module housing IP20 protection for empty slots on the termination unit |
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S900-IP920S |
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Power Supply | S900-SA920N | S900-SA920B | S900-SA920S |
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Redundant Termination Unit for 16 I/O-modules redundant communication and power |
S900-TU921N | S900-TU921B | S900-TU921S |
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Description | Non Ex | Ex Zone 2 | Ex Zone 1 |
Power Supply, only for CB220 for 24 V DC |
S900-SA911N | S900-SA911B | S900-SA911S |
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Compact BoxThe compact box connects 4 I/O modules, 1 power supply and 1 communication module, IP66 (nema 4). | S900-CB220N | S900-CB220B | S900-CB220S |
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Modules and Communication Interfaces see tables above | ![]() |
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