The proliferation of Ethernet networking technology from the office environment to industrial environments for use in real-time mission critical control applications requires a level of immunity to electromagnetic interference (EMI) well beyond what is currently delivered by commercial grade networking products. In fact even the EMI immunity requirements prescribed by IEC 61000-6-2 (Generic Standards – Immunity for Industrial Environments) are inadequate for many environments.
RuggedCom has responded to this challenge by developing Zero-Packet-Loss technology to provide error-free communications
for high EMI environments.
IEC 61850-3 and IEEE 1613 for Substations
One such environment is the electric utility substation where EMI levels can be significantly higher than those of the generic industrial environment defined in IEC 61000-6-2. In order to address this risk, both the IEC and IEEE have developed and issued new standards addressing EMI immunity requirements for communications networking equipment in electric utility substations.
IEC 61850-3 Communications Systems and Networks in Substations (Section 5.7)
IEEE 1613 - IEEE Standard Environmental and Testing Requirements for Communications Networking Devices in
Electric Power Substations
Both groups borrowed heavily from the respectivestandards used for Protective Relaying devices which are critical devices used for protection and control of the power system. Since more and more protection relays are utilizing Ethernet communications it was only natural that the communications also be made to comply with the same EMI immunity requirements.
In both cases the standards have a minimum requirement that the networking equipment operate without any physical damage, reset
or latch-up during the application of a variety of destructive EMI immunity type tests. IEC 61850 has multiple classifications of performance and requires that communications used for protection functions operate without error or delays. IEEE 1613 defines two classes of networking devices: Class 1 devices allow communications errors while Class 2 devices allow zero errors during the application of
EMI type tests.
Type Tests Required for Zero-Packet-Loss
Zero-Packet-Loss™
RuggedCom’s approach was to develop technology which would withstand all of the EMI type tests required by IEC 61850-3 without experiencing any communications loss or delays and also qualify as an IEEE 1613 Class 2 error free networking device. This technology is known as Zero-Packet-Loss™ technology and it is designed to provide the same level of EMI immunity performance and reliability as protective relaying devices.
Zero-Packet-Loss performance is tested by do the following:
A network simulator/analyzer (e.g. SmartBits) is used to generate communications traffic on all ports and at close to
100% frame rate (e.g. 99%).
Industry standard transient and EMI generators are used to perform the 15 destructive EMI type tests which simulate the many types of EMI phenomena found in substation environments.
As the type tests are performed the ingoing and outgoing communications packets are monitored.
To be Zero-Packet-Loss capable the device must experience zero communications errors, delays or losses during each type test
Testing for Zero-Packet-Loss Performance
RuggedCom Inc.
30 Whitmore Road, Woodbridge, Ontario, Canada, L4L 7Z4
Tel: +1 (905) 856-5288 I Fax: +1 (905) 856-1995 I Toll Free: +1 (888) 264-0006
