iRTUe – Distributed I/O for Gateways & RTUs
iRTUe remote expansion units provide digital and analog I/Os with IEC 61850 GOOSE- IEC 61850 GOOSE (Generic Object Oriented Substation Events) communication (Publisher/subscriber)
- High speed processing time — type 1A class performance P2/3
- Flexible configuration of two I/O cards per unit with digital & analog inputs and relays
- Sate-of-the-art & secured technology for advanced automation functionalities like load shedding or interlocking
- Serial (EXP422) or double Ethernet port (copper or fiber) to connect to iRTUs/iGWs or any other third party master unit
- Multicast MAC addresses
- Time synchronization via PTP/IEEE1588 or NTP
- Use GGIO data models or custom SCL files
- Power quality measurements with the specialised iRTUe‑Q
Our remote I/O expansion units communicate with IEC 61850 GOOSE, allowing to extend and distribute the acquisition and command capabilities of IEC 61850 masters (GOOSE subscribers). We offer flexible I/O board configurations to fulfill any application requirement, making the iRTUe the perfect choice to both set-up and retrofit electrical communication networks.
Contemporary substation automation calls for advanced I/O modules to provide modern services such as interlocking or load shedding. These functionalities rely on state-of-the-art characteristics, which cannot be realised with serial communication media and old protocols. For this reason, the iRTUe executes IEC 61850 GOOSE messaging in a processing time under 3ms.
They connect via double Ethernet (RJ45, ST or SC) or serial (EXP422) port and are synchronized with IEEE 1588 (PTP) to ensure optimal time accuracy. This allows the iRTUe to communicate with any other equipment in the network: for instance RTUs, gateways, other iRTUe modules and third-party IEDs on the substation process bus.
iRTUe I/O Expansion Unit
- Serial (1) RS-422 port to connect to iRTU&iGW devices with ModbusRTU
- Ethernet (2) 10/100BaseTX ports, RJ45 or FX100 fiber optics with ST or SC connectors
- Up to 48 Digital Inputs, 16 Relays and 16 Analog Inputs
- Protocols IEC 61850 GOOSE messaging & Modbus RTU
Features & Functionalities
Time Synchronization via NTP and IEEE 1588 (PTP client)
Supports PRP, HSR and RSTP redundancy protocols
Time response under 3ms (type 1A class P2)
Freely distributable & configurable Inputs & Outputs
Multiple connection options
Made for advanced IEC 61850 substation automation schemes
iRTUe Substation Application
Example schema

Technical Features
IEC 61850 GOOSE
GOOSE communication works with enhanced retransmission mechanisms on a publisher/subscriber basis, allowing P2P communication between iRTUe and IEDs with a processing time under 3ms (performance class P2).
IEC 61850 GOOSE also features strong VLAN and priority tagging functionalities via IEEE 802.1Q to send messages efficiently across complex physical networks. Combined with a substation-wide Ethernet LAN, it enables flexible and sophisticated logic schemes for substation protection and automation, such as interlocking and load shedding.
Since these systems are based on software configurations rather than hardwired signal paths, they are more cost-effective, easily extendable and on demand reconfigurable, making them highly adaptive to changing substation configurations and network topologies.
The operational reliability of these schemes is significantly enhanced by GOOSE’s continuous and inherent supervision of the communication and the message’s data integrity.
With its strong IEC 61850 GOOSE capabilities, the iRTUe is the perfect I/O extension to employ these advantages.
Standards and Compliance
The diverse backgrounds of our partners and clients from all over the world have helped us gather state-of-the-art know-how and firsthand experience in a great variety of energy applications. This joined knowledge is the foundation of our optimized iRTU/GW family, which has a proven track record of being particularly effective and resistant for a diverse range of applications and harsh environments belonging to the energy industry.
As a result, the iRTUe meets the requirements of extensive standards, such as IEC61850‑3, IEC60870‑2–1 & IEC60255-26.
Inputs and Outputs
Digital Inputs & Outputs
Each input can be defined as input or as a counter and have an individually configured debounce filter. One iRTUe unit can provide up to 48 isolated digital inputs with a 2.5kVrms isolation and a 1 ms timestamp accuracy. The units come in standard input voltages of 24, 48, 125 or 220 Vdc.
On the output side, one unit can provide up to 16 dry contact electromechanical relay outputs. Their maximum breaking capacity 8A at 220Vac and 8, 0.3 and 0.12A at 30, 110 and 220Vdc respectively. Grouping relay outputs in blocks of 2.Isolation between solenoid and contacts: 6 kV.
Analog Inputs
One iRTUe unit can can provide up to 16 analog inputs with an isolation of 2.5kVrms. They are offered with a range of 4 20 mA and +/-10 Vdc and have an accuracy of 0.15%.
Power Quality Analysis
With 3 voltage and 3 current inputs, the iRTUe#Q family can measure all power quality parameters (frequencies, currents, phases etc.) and store the data in COMTRADE files.
Simple Configuration
iRTUe addresses, in both Modbus and GOOSE, can be easily configured using the side microswitches. For GOOSE, the default multicast group is set to zero (modifiable with iConf).
Models Overview
Each iRTUe auxiliary unit includes up to two I/O cards with rated input voltages of: 24 Vdc, 48 Vdc, 125 Vdc or 220Vdc (other ranges upon request). They can be assembled as follows:
iRTUe#D1D1: 48 Digital Inputs.
iRTUe#R1R1: 16 Relay Outputs.
iRTUe#A1A1: 16 Analog Inputs (0–20mA)
iRTUe#D1R1: 24 Digital Inputs + 8 Relay Outputs
iRTUe#D1A1: 24 Digital Inputs + 8 Analog Inputs (0–20mA)
iRTUe#R1A1: 24 Digital Outputs + 8 Analog Inputs (0–20mA)
iRTUe#Q: 3 voltage inputs at 110Vac through four pin 5.08mm terminal block connectors + 3 current inputs for 1A current transformers, via 6 pin 5.08mm terminal block connectors
iRTU#Q2: 3 combined inputs using an RJ45 connector, for passive smart sensors based on IEC 60044–7/8
Other configurations upon request
Specifications
General Characteristics
Power supply W : wide range, 32 — 250Vdc / 80 — 250Vac (2.5kVrms isolation) 24 : 19.5–60Vdc (2.5kVrms isolation) |
MTBF 177,000h (one hundred seventy seven thousand hours) |
Environmental Operating temperature : ‑25ºC to +70ºC IEC 60068–2‑1, IEC 60068–2‑2, IEC 60068–2‑3, IEC 60068–2‑14, IEC 60068–2‑30, IEC 60068–2‑38 |
Vibration & shock test IEC 60068–2‑6, IEC 60068–2‑7 |
Physical external dimensions: 173 x 78.4 x 137 mm (HxWxD) |
Configuration simple configuration with iConf tool |
CPU 32 bits microcontroller @ 40MHz |
Digital Inputs
Isolation 2.5 kVrms |
Activation ON when Vi>85%Vn | OFF when Vi<60%Vn | other levels upon request |
Connectors MVSTBR 2,5 9 pins — grouping digital inputs in isolated blocks of 8 inputs and one common terminal |
Relay Outputs
Isolation 6 kVrms |
Contact Dry |
Connectors MVSTBR 2,5 4 pins – grouping relay outputs in blocks of 2 |
Breaking Capacity 8A @ 220Vac – 8/0.3/0.12A @ 30/110/220Vdc |
Communication Features
Serial (1) RS-422 port to connect to iRTU&iGW devices with ModbusRTU |
Ethernet (2) 10/100BaseTX ports, RJ45 or FX100 fiber optics with ST or SC connectors |
Time Synchronization IEEE 1588 (PTP-Precise Time Protocol) client |
Protocols IEC 61850 GOOSE messaging or Modbus TCP/RTU |
IEC 61850 Logical Nodes GGIO predefined (future firmware upgrades will allow any SCL file) |
Time response under 3ms following the performance test in IEC 61850 (type 1A class P2) |
Analog Inputs
Isolation 2.5 kVrms |
Accuracy 0.15% after calibration |
Connectors MVSTBR 2,5 4 pins – grouping analog inputs in blocks of 2 |
Ranges 4–20mA (+/-20% tolerance), +/-10Vdc |
EMC Standards
IEC 60950–1, IEC 60255–5:2000, EC 60255–22:2000, EN 55022, IEC 61000–6‑4, IEC 61000–6‑5, IEC 61000–4‑2, IEC 61000–4‑3, IEC 61000–4‑4, IEC 61000–4‑5, IEC 61000–4‑6, IEC 61000–4‑8, IEC 61000–4‑9, IEC 61000–4‑10, IEC 61000–4‑12, IEC 61000–4‑16, IEC 61000–4‑17, IEC 61000–4‑18, IEC 61000–4‑29 |
iGrid Masters for iRTUe Units
iGW – The Perfect Master for iRTUe Units
The iGW is a powerful and reliable substation gateway, able to run either in standalone or redundant modes, carrying 4 serial ports and an (optional) embedded Ethernet switch for 2 additional Ethernet ports (total of 4).
iGWlite – The “Litest” Gateway for iRTUe
The iGWlite comes with 1 Ethernet, 1 RS485/RS422 and an optional RS-232 port (copper or fiber) or a 2G/3G/4G modem – taking little space on a DIN-Rail, but still employing the full iGrid protocol suite.
iRTU – The Gateway with Integrated I/Os
The iRTU is an intelligent and scalable bay controller with internal and configurable I/O capabilities for direct data acquisition, powerful protocol conversion (incl. IEC 61850), high-precision timestamping and an optional embedded Ethernet switch.
iRTUe References

Power Quality Analyzer & I/O Expansion Unit
- High-accuracy 3‑phase measurements
- 3 Current Inputs
- 3 Voltage Inputs
- Frequency and Power factor measurements
- Optional I/O card configurations
- EXP-422 serial connection
- iRTUeQ2: 3 combined inputs, using RJ45 connector, for passive smart sensors based on IEC 60044–7/8
Features & Functionalities
Measurements according to IEC 60044–8
Configurable Sag & Swell Alarms
Configurable Overcurrent Alarms
Submetering
Modbus RTU & IEC 61850 GOOSE
High-accuracy time synchronization via NTP
Multiple connection options
Super compact DIN-rail mounting
Any questions?
Common iRTUe Applications
Substation Automation
PLC & PAC I/O Expansion
RTU I/O Expansion
Gateway I/O Expansion
Power Quality Measurement
Generation Dispatch
Interlocking with GOOSE
Generation Control
Substation Data Acquisition and Control
Electricity Distribution Networks
Intelligent Load Shedding
Railway Data Collection
HV SAS with Modbus
In this substation automation project two different configurations of iRTUe units acquire data of four bays operating at 230kV and ten bays at 33kV. The iGW reports this data to the control center and to the iControl SCADA HMI via IEC 60870–5‑104.
MV Grid Automation with IEC 61850
In this project the iRTUe units help the iRTU collect data data via IEC 61850 in order to automate 9 medium voltage substations at the Sabiha Gökçen Airport (Turkey)
iGW-VM – unlimited control
The freely scalable iGW-VM supports all architectures using Windows or Linux, acting as a substation gateway, bay controller, RTU or communication front-end for SCADA systems. The iGW-VM is thus the perfect software choice for projects with a predetermined/preferred hardware or a large grid to cover (high number of datapoints).

iControl SCADA
High-performance SCADA for the visualization and control of substation data. It is able to run either in client/server or standalone modes, providing advanced functionalities such as hot-standby redundancy, automatic line coloring, events notification (via e‑mail and sms), SQL logging, and reports generation.
Substation Automation with IEC61850
HV Substations
MV Distribution Grids
Railway Automation
Protocol Conversion
Smart Metering
Wind Farm Generation
Hydroelectric Generation
Photovoltaics Generation
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