R. STAHL IS1+
Remote I/O System
IS1+ Remote I/O System
Remote I/O for modern process plants, hazardous areas and digital infrastructure.
The R. STAHL IS1+ Remote I/O System is a market-leading automation platform designed to safely bring field signals, diagnostics and process data from hazardous areas into the control layer. Suitable for installation in Zone 1 environments, IS1+ helps reduce complex hardwiring, simplify expansion projects and support smarter plant operation.
As industrial systems become more connected, traditional point-to-point wiring can become expensive, space-consuming and difficult to maintain. IS1+ offers a more efficient approach by placing intelligent remote I/O closer to the process, where signals from sensors, valves, switches and instruments can be gathered and transmitted digitally through robust intrinsically safe networks.
The result is a cleaner control architecture, easier commissioning, improved diagnostics and a system built for long-term industrial use.
What is the IS1+ Remote I/O System?
IS1+ is a modular Remote I/O platform developed for hazardous areas and harsh industrial environments. It allows process signals to be collected in the field and sent back to the automation system using a range of communication protocols.
Rather than running large volumes of individual cables from every device back to the control room, IS1+ enables decentralised signal handling closer to production assets. This can significantly reduce installation effort, cabinet requirements and future modification costs.
R. STAHL has continuously developed the IS1+ platform, making it one of the most widely recognised Remote I/O solutions for hazardous area automation worldwide.
How the System Works
Remote I/O Installed in the Field
IS1+ stations are positioned close to instruments and equipment in hazardous areas. Signals from field devices are terminated locally and processed through the system’s modular I/O hardware.
Digital Communication Back to Control Systems
Once signals are collected, they are transmitted back to PLC, DCS or SCADA systems using supported industrial communication protocols. This allows central monitoring and control while reducing traditional wiring infrastructure.
Modular Expansion
The system can be configured with a wide range of analog, digital and temperature I/O modules, making it suitable for both small installations and large process plants.
Built-In Diagnostics
Integrated system diagnostics help identify faults, communication issues and device conditions early, helping maintenance teams respond faster and minimise downtime.
Key Advantages
Reduce Wiring and Installation Costs
By placing I/O closer to the process, IS1+ can dramatically reduce the amount of multicore field wiring required between plant areas and control rooms.
Save Valuable Cabinet Space
Less marshalling and termination hardware is needed, helping reduce cabinet size and control room footprint.
Flexible for Mixed Plant Environments
The IS1+ platform supports multiple communication protocols, making it suitable for sites operating a mix of old and new control systems.
Faster Commissioning
Simplified architecture and modular design help speed up installation, testing and startup activities.
Improve Plant Availability
Advanced diagnostics provide early warning of faults and support predictive maintenance strategies.
Long Service Life
Designed for demanding industrial use, IS1+ is built to support long-term operation even in harsh environments.
Built for Digitalisation and Modern Automation
The latest IS1+ generation supports advanced communication technologies designed for modern plants. This includes intrinsically safe Ethernet using 100BASE-TX-IS, allowing high-speed data communication directly in hazardous areas.
The platform is also well suited to modern automation concepts such as modular process systems, packaged skids and future-facing plant digitalisation strategies.
For users modernising existing assets or building new facilities, IS1+ provides a scalable and future-ready route forward.
Supported Communication Protocols
PROFINET
EtherNet / IP
PROFIBUS DP
Modbus TCP + RTU
HART-IP
OPC UA
Built for Harsh Industrial Environments
IS1+ is engineered for demanding operating conditions and can be used in ambient temperatures from -40°C to +75°C.
This makes it suitable for exposed outdoor installations, offshore applications, marine environments and process areas where long-term reliability is essential.
The robust modular design also helps support maintenance and future expansion throughout the system lifecycle.
Flexible Modules and System Components
The IS1+ platform includes a broad range of modules and accessories to support different automation requirements.
Available options include:
- Digital input modules
- Digital output modules
- Analog input modules
- Analog output modules
- Temperature input modules
- Power supply modules
- Communication modules
- Fibre optic options
- Field enclosures
- Device management tools
This modular approach allows each system to be tailored to the needs of the application.
Need Advice on Remote I/O for Hazardous Areas?
Speak with Exloc about the R. STAHL IS1+ system for upgrades, expansions or new hazardous area projects.
Communications modules for Zone 1 and Zone 2 or Division 1 and 2
| Protocols | Installation | Max. no. of I/O modules | Power supply | Type series |
|---|---|---|---|---|
| PROFIBUS DP or Modbus RTU | Zone 1 / Div. 1 | 8 | 24 V DC* / 120/230 V AC | 9440/22 |
| Modbus TCP or EtherNet/IP or PROFINET | Zone 1* / Div. 1 | 8 | 24 V DC | 9441/12 |
| PROFIBUS DP, PROFINET, EtherNet/IP and Modbus TCP | Zone 2 / Div. 2 | 16 | 24 V DC | 9442/35 |
| PROFIBUS DP, PROFINET, EtherNet/IP and Modbus TCP | Zone 1 | 16 | 24 V DC | 9442/32 |
* not for new projects
Zone 2 and Division 2 I/O modules, Ex i signals
| Function | Channels | Application | Type series |
|---|---|---|---|
| Analogue Universal Module HART | 8 | Analogue inputs/outputs: 0/4 … 20 mA with HART | 9468/33-08-10 |
| Temperature Input Module | 8 | Resistance thermometers (2-, 3-, 4-wire), THCs, potentiometers, joysticks | 9482/33-08-10 |
| Digital Input Output Module | 16 | Digital inputs/outputs: Contacts, proximity switches, low-power solenoid valves | 9470/33-16-10 |
| Digital Output Module | 8 | Solenoid valves 12.6 V / 30 mA | 9475/33-08-50 |
| Digital Output Module | 8 | Solenoid valves 17.5 V / 30 mA | 9475/33-08-60 |
Zone 2 and Division 2 I/O modules, non-Ex i signals
| Function | Channels | Application | Type series |
|---|---|---|---|
| Universal Module HART | 8 | Analogue and digital Ex ec inputs/outputs: 0/4 … 20 mA with HART, pnp contacts, digital output 24 V / 0.5 A; SIL2 output shutdown | 9469/35-08-12 |
| Digital Input Output Module NAMUR | 16 | Digital Ex ec inputs/outputs: Contacts, (pnp) proximity switches, low-power solenoid valves | 9471/35-16-11 |
| Digital Output Module 24 V | 16 | Digital Ex ec inputs/outputs: Contacts, (pnp) proximity switches, 24 V / 0.5 A solenoid valves; SIL2 output shutdown | 9472/35-16-12 |
| Digital Output Module Relais | 8 | Integrated NO relay contacts Ex ec for loads up to 250 V AC / 2 A | 9477/15-08-12 |
Zone 1 and Division 1 I/O modules, Ex i signals
| Function | Channels | Application | Type series |
|---|---|---|---|
| Analogue Universal Module HART | 8 | Analogue inputs/outputs: 0/4 … 20 mA with HART | 9468/32-08-10 |
| Temperature Input Module | 8 | Resistance thermometers (2-, 3-, 4-wire), THCs, potentiometers, joysticks | 9482/32-08-11 |
| Digital Input Output Module | 16 | Digital inputs/outputs: Contacts, proximity switches, low-power solenoid valves | 9470/32-16-10 |
| Digital Output Module | 4 | Solenoid valves 11.3 V / 40 mA; SIL2 output shutdown | 9475/32-04-12 |
| Digital Output Module | 4 | Solenoid valves 12.3 V / 75 mA; SIL2 output shutdown | 9475/32-04-22 |
| Digital Output Module | 4 | Hydraulic valves 12.3 V / 75 mA; SIL2 output shutdown | 9475/32-04-72 |
| Digital Output Module | 8 | Solenoid valves 12.6 V / 30 mA; SIL2 output shutdown | 9475/32-08-52 |
| Digital Output Module | 8 | Solenoid valves 17.5 V / 20 mA; SIL2 output shutdown | 9475/32-08-62 |
Zone 1 and Division 1 I/O modules, non-Ex i / pneumatic signals
| Function | Channels | Application | Type series |
|---|---|---|---|
| Digital Output Module Valve | 8 | Pneumatic control of valves via 3/2-way solenoid valves with 2.5 … 7 bar; SIL2 output shutdown | 9478/22-08-51 |
| Digital Output Module Relais | 6 | Integrated relay contacts for loads up to 250 V AC / 2 A | 9477/12-06-12 |
| Digital Output Module Relais | 8 | Integrated relay contacts for loads up to 60 V AC / 2 A | 9477/12-08-12 |
Zone 1 signal converter modules for non-Ex i signals
| Function | Channels | Application | Type series |
|---|---|---|---|
| mA-Isolating Repeater | 1 | For 4-wire transmitters, Ex i or Ex e connection to 9468 modules, incl. HART | 9164/13 |
| Electronic Relay | 1 | Switching of Ex e load, max. 253 V AC, 5 A with 9475 modules | 9174 |
| Relay Module | 1 | Switching of Ex e or Ex i load, max. 253 V AC, 125 V DC / 2 A with 9475 modules | 9177 |
