SE Modicon M580 Brochure
Modicon M580 automation platform Modicon M580 Communication modules RTU communication Presentation RTU protocols and Telemetry systems provide a robust means of communication suitable for the process values, maintenance, and remote monitoring needs of infrastructures disseminated over a vast geographical area that may be difficult to access. RTU systems are designed to meet the needs of the water industry, the oil and gas sector, and other infrastructures, where remote monitoring and telecontrol are essential to the effective management of sites and substations spread over a wide geographical area. An RTU system consists of the following elements: b A Telemetry Supervisor (SCADA) in a central control room b A network infrastructure and a variety of suitable communication methods (LAN, WAN, modems, etc.) b A large number of RTU substations geographically distributed throughout the field
Presentation
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SCADA master station
TCP/IP, LAN/WAN, XdSL, or Serial networks PSTN (Public Switched Telephone Network) or GPRS/3G modem connections Radio modem connections
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Example of an RTU system architecture RTU communication protocols Currently, people working in the industrial Telemetry sectors use standard protocols for communication between control centers (SCADA) and RTU stations. The most commonly used protocols are as follows: b IEC 60870-5: IEC (International Electrotechnical Commission), in particular IEC 60870-5-101/104 (commonly known as IEC 101 or 104) b DNP3: Distributed Network Protocol version 3 DNP3 is the predominant protocol in North America, Australia, and South Africa whereas, in certain European countries, the IEC protocol is required by law. IEC is also commonly used in the Middle East. The geographical distribution of these protocols is as follows: b DNP3: North America, Australia, New Zealand, UK, Asia, South America, etc. b IEC 60870-5: Europe, Middle East, Asia, South America, etc. These protocols offer similar functions. They are both particularly suited to “transient communications” (modem, radio) and data exchanges with limited bandwidth for the following reasons: b They transfer data in a very robust manner between the SCADA system and the RTU devices b They are essentially “event-triggered” protocols (exchanges on changes of state, exchanges of time- and date-stamped events). They offer the following transmission modes: b Interrogation via polling b Data exchanges on changes of state (RBE: report by exception) b Unsolicited messaging (a slave station can start an exchange of data with the master station) Both protocols offer native data management and time- and date-stamped events: b Time synchronization between the master station and auxiliary stations via protocol functions b Time- and date-stamping of data and events b Automatic transfer of time- and date-stamped events between the RTU stations and SCADA (control room)
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