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Smart RTU solution

A remote terminal unit (RTU) is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system or SCADA (supervisory control and data acquisition system) by transmitting telemetry data to the system and employing messages to control the connected objects from the supervisory system.

The automation technology is rapidly advancing. New communication techniques, devices and standard protocol interfaces combined with the immense computing power of today’s hardware components open the way to new concepts in automation. At the same time, the growing demands of utility owners for more cost-effective control systems must be met.

Enilit RTU is our solution for automation. Modular and open structure of the Enilit RTU system sets a wide range applications:
Electric power generation plants Electricity transmission and distribution networks
Monitoring and control of chemical and petrochemical plants and pipelines Environmental technology with measured data acquisition and remote evaluation
Traffic control systems (railways, metro, tramways and etc.) Supply networks of municipal and regional public utilities (gas, electricity, water, sewage, district heating, etc.)
Data acquisition and control in building engineering systems (escalators, lighting, air conditioning, etc.)    
Enilit RTU - flexible and compatible solution

Enilit RTU offers cost effective solution for classic RTU functions. Gathering of direct-wired process information and transferring it to a higher level control system is one of the primary tasks of the remote terminal unit Enilit RTU. Also there are a lot of protection terminals, control, metering and other automation devices that need to be connected together in one system. Enilit RTU is able to communicate with various sub RTUs, IEDs and upper RTUs, SCADA control centres using all supported protocols at the same time. Each communication port can be configured for different protocol independently.

• Enilit RTU comes in two 19" wide and 6U high aluminum frame system racks. Connection between racks max. 15 m length.

• Main RACK:

- 2 x PS boards;

- 1 x CPU board;

- 12 x inputs / outputs boards;

• Extension with double RACK:

- 2 x PS boards;

- 16 x inputs / outputs boards;

• Dl, DO, Al or ST boards could be installed in any order according to the customer request. Any type of module is allowed to be inserted in any slot.

• Environmental working conditions (tested and certified):

- Dry heat: 70°C for 24 hrs;

- Damp heat: 95% RH and 40°C for 48 hrs.

Power supply PS module


• Two redundant power supply
modules can be installed;

• The second module works as a
redundant hot standby power supply, switching reaction time is immediate;


• Input range:

- PS 11 : 115V AC;

- PS 21 : 230V AC;

- PS 31 : 110V DC;

- PS 41 : 220V DC;

- PS 51 : 48V DC.




Central processor CPU module

• 64-bit Intel Atom microprocessor of 1.6 Ghz, 2 GB Dynamic memory DRAM;


• 32GB SSD disk (for software, databases, events, waveforms, parameters);


• 4 pcs. Ethernet-based 10/100 BaseTx ports (not switched - all 4 ports are able to work with different information network gateway and have unique MAC)


• 12 pcs. of RS232/RS485 COM ports (RJ45 interface):
- CPU 41 has 12 x RS485 ports;
- CPU 42 has 4 x RS232 + 8 x RS485 ports;
- CPU 43 has 8 x RS232 + 4 x R5485 ports;
- CPU 44 has 12 x RS232 ports.



Digital input DI module


• 24 pcs. optically isolated Dl with one common minus for each 8 inputs;


• Input types: digital input, BCD code, pulse counter;


• Each digital input can be configured as a single or double signal on the same Dl module;


• LED indication for each digital input status;


• Input range:

- Dl 11 : 24 Vdc (16 ... 30V);
- Dl 21 : 48 Vdc (34 ... 72V);
- Dl 31 : 110 Vdc (80 ... 150V);
- Dl 41 : 220 Vdc (150 ... 264V).


Digital output DO-31 module

• 24 pcs. single pole relays with one normally open (NO) contact;


• Each digital output channel can be configured as Latch Type Short or Long Pulse Type and can be executed in either Direct Execute or Select Before Operate Execute manner;


• Each digital output can be configured in a single or
double remote control or a set point output on the same module;


• LED indication for each digital output status;


• Contact ratings according to EN60947-5-1:
- AC15, 250 VAC, 3A;
- DC13, 24 VDC, 2A;
- DC13, 250 VDC, 0.2A.



Communication module ST-61


• Connector type ST glass fibre optic


• Six communication chanels can be used for RS serial type protocols as IEC 60870-5-101,

IEC 60870-5-103, DNP 3.0 serial, Modbus serial and other;

• Status LED indication for every channel;


• 1 pcs. of RS-485 port to connect to the CPU COM port via external cable.




Analog input AI-31 module


• 12 pcs. of independent optically isolated analog inputs;


• Input range (current or voltage are selectable for each input by the internal jumper position):
- Al 31 current: -20mA to +20mA;
- Al 31 voltage: -10V to 10V;


• lower and upper range limits for each analogue input can be defined separately;


• LED indication for each analog input status;


• 20 ms time tagging;


• 16 bits ADC.



Communication module PL-61


• Connector type plastic optic


• Six communication chanels can be used for RS serial type protocols as IEC 60870-5-101,

IEC 60870-5-103, DNP 3.0 serial, Modbus serial and other;

• Status LED indication for every channel;


• 1 pcs. of RS-485 port to connect to the CPU COM port via external cable.




Communication module CK-61

• Connector type RJ-45

• Six communication chanels can be used for RS serial type protocols as IEC 60870-5-101,

IEC 60870-5-103, DNP 3.0 serial, Modbus serial and other;

• Status LED indication for every channel;


• 1 pcs. of RS-485 port to connect to the CPU COM port via external cable.




Enilit CMS – unique and user-friendly software

Enilit CMS is the software, a hundred percent programmed by the engineers of UAB Enilit, for the configuration and management of Enilit RTU.


Windows based Enilit CMS tool enables to configure I/O features, Master, Slave protocols, PLC, Tags connections and also performs live diagnostics at local stations and remotely over TCP/IP.

The unique software Enilit CMS is the core tool which makes Enilit RTU most user-friendly and cost-efficient:

• The configuration of Enilit RTU is carried out on line on the device (no compilation, no upload, no restart) and no other software or cable is needed, which saves a lot of time during the commissioning or service.

• The built-in communication protocol analyzer, real time signal and command testing tool allows seeing on-line the data received and sent through Enilit RTU and to simulate each signal, command or measurement from Enilit RTU through each of protocols.

• Unlimited programmable logic (no TAG limitation).

Enilit CMS download
To download our Enilit CMS software you need to fill the request form. After a while you will get software download link in your email. Enilit CMS software runtime is limited to 24 hours, it will stop all communications, You will need to restart the application after communication stops. To order the software without limitation please write to 
Request of software download
Data concentrator / Protocol gateway
A wide range of supported protocols and hardware ports makes Enilit RTU useful in any situation where data concentrator or protocol gateway is needed. Protocol gateway monitors, manages and maintains the remote equipment.

The gateway includes the following features:

• Multi-protocol to access new and existing lEDs;

• Two-way data exchange using standard communications protocols;

• A gateway between energy protocols and OPC DA/UA for multi-vendor SCADA software;

• Unlimited multiple sessions (Server, Client or both) of:

- IEC 61850 (client) with PRP (IEC 62439-3 PRP-1);

- IEC 60870-5-101 (master and slave);

- IEC 60870-5-103 (master);

- IEC 60870-5-104 (client and server);

- DNP3 serial and TCP/IP (client and server);

- Modbus RTU/ASCII serial and TCP/IP (client and server);

- SPA-BUS (master);

- OPC DA2;

- other protocols on request;

• Parallel Redundancy Protocol (IEC 62439-3 PRP-1) supported as a standard without an extra "red box";

• A programmable PLC logic that complies with the RTU

IEC 61131-3 standard.

Programmable Logic Controller (PLC)

Enilit RTU can also perform as a Programmable Logic Controller (PLC). A soft logic automation tool ISaGRAF is used to provide PLC functionality. ISaGRAF is an industrial automation software technology for creating standalone controllers or distributed control systems. It is compliant to the standard IEC-61131-3 and gives great flexibility to adjust Enilit RTU hardware platform and operating system to meet any client's needs.

Redundant RTU solution
Hot-Standby redundancy is a default setting used in Enilit RTU.

The primary RTU and secondary RTU systems run simultaneously. The data is mirrored to the secondary RTU in real time so that both systems contain identical information. This method allows switching over fast from active to standby RTU because both of the RTUs have the same data. Even if the serial connection speed 115,200 kbs is used, it is possible to transfer about 500 events per second between the RTUs.

To support redundancy, RTUs must be connected with each other with minimum one LAN, RS-485 or RS-232 interface cable. These communication paths are used to exchange real time data between the active to the standby RTU.

It is possible to use a maximum of 4 redundant connections between RTUs.

• RS-485 or RS-232 (COM1-COM12);

• RS-485 or RS-232 (COM1-COM12);

• LAN (ETH1-ETH4);

• LAN (ETH1-ETH4).


Enilit RTU has been tested and certified in conformity with the following EC Directives:


EMC Directive 2014/30/EC

IEC EN 55022:2010;

IEC EN 55024:2010;

IEC EN 61000-3-2:2006;

IEC EN 61000-4-2:2009;

IEC EN 61000-4-4:2012;

IEC EN 61000-4-5:2006;

IEC EN 61000-4-6:2014;

IEC EN 61000-4-8:2010;

IEC EN 61000-4-16:2015;

IEC EN 61000-4-17:2008;

IEC EN 61000-4-18:2011;

IEC EN 61000-4-29:2004.

LVD Directive 2014/35/EC

IEC EN 60950-1:2006/A11:2009.

Environmental testing

IEC EN 60068-2-2:2007;

IEC EN 60068-2-78:2013;

(95% RH and 40°C for 48 hrs. & 70°C for 24 hrs).

Enilit CMS software IEC 61850 Ed.2

protocol implementation tested in KEMA DNV GL

Enilit CMS software IEC 60870-5-104 Ed.2

protocol implementation tested in KEMA DNV GL




First Power Supply:

Redundant Power Supply:

RS232/RS485 communication ports:

Fiber optic ports:

Binary I/O operating voltage:

Binary inputs:

Binary outputs:

Analog inputs:

You need to order following items for your application. Please send a copy to to order Enilit RTU.