The number of integrated outputs amounts to 10 and can be extended up to more than 100. The DTS system is basically equipped with 2 TCP/IP interfaces, USB and RS232, through which status, alarm or temperature data can be transferred to PC or PLC systems.
Equipped with an embedded communication module the EN.SURE DTS evaluation unit is accessible by Ethernet/ LAN, holds its own IP address and is compatible with DHCP.
The on-board storage facility of measurement data provides automatic buffering of network break downs. It can handle multiple protocols, so the DTS can be directly linked to PLC or SCADA systems and communicates in various industrial protocol standards providing measured data and customised alarm information.
Direct links to SCADA for customer specific protocol solutions
- LIOS EN.SURE can communicate in parallel with its proprietary protocol and one or more customer specific protocols like DNP3, IEC60870-5-104, IEC61850, XML WITSML, Modbus (Master/Slave) etc.
- Individual assignments for protocols and client addresses (IP) possible
The most common industrial protocols used in electrical systems worldwide are introduced in the following section. However, also other protocol standards are available or can be implemented for EN.SURE.
The MODBUS protocol was published by Modicon in 1979. It is a quite simple single master – multiple slave protocol widely used in general purpose SCADA applications. It provides binary (bit) and 16-bit integer data, but no floating point values, polled by the master, i.e. the slave cannot send data spontaneously. The protocol specification is openly published and royalty-free. In EN.SURE DTS, TCP/IP is used as transport layer.
IEC 60870-5 provides a communication profile for sending basic Telecontrol messages between systems. It was developed by the IEC Technical Committee 57 (Working Group 03) as a protocol standard for Telecontrol, Teleprotection, and associated telecommunications for electric power systems. The result of this work is IEC 60870-5. The protocol provides inter alia bit, integer and floating point data with or without time stamps. Data is transmitted from controlled stations (slaves) either by polling or spontaneously. For EN.SURE the IEC 60870-5-104 companion standard, defining standard TCP/IP connections as transport layer, is used.
DNP3 (Distributed Networking Protocol) is an open standard managed by the DNP User Group. Initially; the DNP3 protocol was developed by Westronic (now GE-Harris) in 1993. It is widely used in electrical systems worldwide, including North and South America, the UK, Southeast Asia, South Africa, Australia, and New Zealand. It has gained wider use beyond electrical utilities, e.g. for water supply as well. The DNP3 protocol is also referenced in IEEE Std. 1379-2000, which recommends a set of best practices for implementing modern SCADA Master-RTU/IED communication links.
The protocol provides bit, integer and floating point data and time stamps. Data is transmitted from the outstation (slave) either by polling or spontaneously. EN.SURE DTS uses TCP/IP as transport layer, but even in this mode the DNP3 protocol additionally uses its own protocol stack for synchronisation and error checking. This provides extra security.