The requirement was to provide industrial Ethernet connectivity between the SEL IEDs in the newly added substations and Foxboro SCD5200 RTUs. The RTUs will be in turn connected to the existing Honeywell SCADA network using a telephone network through Bell-202 Modems.

The project included the addition of new RTUs. The RTUs were to be installed in a redundant setup consisting of Primary Control and Backup control units. Each IED needed to be connected to both control units in every RTU using Ethernet Fiber links, that way if the primary unit fails, the IEDs are still connected to the network via the Backup unit.

The RTUs had 10 BaseFL interfaces available, while the IEDs had 100 BaseFX interfaces, to overcome this communication problem we had to offer an Ethernet switch containing both interface types to facilitate transparent communication between the RTUs and the IEDs.

The existing RTUs were connected to their IEDs using media converters to a copper connection which violated the new SAMSS of Aramco to use only fiber connection for the level 1 of local control units. The new set-up eliminates the need for multiple media converters as the required interfaces are all provided in the same fiber switch to comply with Aramco standards. The new design included only 2 switches per RTU, one for the primary path and the other for the backup path. Therefore, the new design satisfied Aramco / Schneider redundancy requirement with minimum hardware and cost.

The supply of Industrial Substation rated Ethernet switches containing 100BASEFX ports for interfacing with the IEDs, as well as redundant 10BASEFL ports to interface with the RTUs.

The offered port flexibility overcame the communication problem between the RTU and IED (10 BaseFL to 100 BaseFX). In addition, it eliminated the need of using multiple media converters, as the offered solution contained the required interface on the same switch.

Provides Immunity to EMI and heavy electrical surges through a:

• Zero-Packet-Loss™ technology
• Meet IEEE 1613 (electric utility substations)
• Exceeds IEC 61850-3 (electric utility substations)

Designed to operate reliably in demanding environments:

• –40°C to +85°C operating temperature (no fans)
• Hazardous location certification: Class 1 Division

Advanced cyber security features with:

• Multilevel user passwords
• SSH/SSL (128-bit encryption)
• RADIUS centralized password management
• SNMPv3 authentication and 56-bit encryption

Offers a fully integrated in addition to an optional dual-redundant power supply.
Support advanced networking features:

• MSTP 802.1Q-2005 (formerly 802.1s)
• RSTP (802.1w) and Enhanced Rapid
• SNTP time synchronization (client and server)
• Industrial automation features such as Modbus to be connected directly to SCADA