At attended high voltage substations, an RTU server acts as a middle level between field-level devices and upperlevel SCADA.
RTU server communicates with ENIP-2 over local-area network with either radial, or ring, or PRP topology. The latter two require ENIP-2 with double Ethernet ports, supporting RSTP and PRP.
The advantages of ENIP-2 with an Ethernet port:
— faster data transmission rates from control points to RTUs and upper level;
— integration into IEC 61850 substation automation systems;
— switchgear interlocking with GOOSE and logic expressions;
— remote access to devices on a serial line with Ethernet-to-serial conversion.
ENIP-2, ENMI and ENMV-1 are installed at substation control points. ENIP-2 with two Ethernet ports is connected to RTU with a ring network.
Two Ethernet switches complete the ring and connect ENCS-2 time sync module to RTU server.
IEC 61850-enabled ENIP-2 publishes and subscribes to GOOSE messages and, evaluating logic expressions, provides switchgear interlocking. RTU server collects data from the devices, stores it and retransmits it to SCADA. ENCS-2 synchronizes time on RTU server and ENIPs via SNTP.
ENMI-6 diagnostics panel monitors the status of all the components of the software and hardware complex - ENCS-3m, ENCS-2, ESM, ENMV-1, switches, UPS - via SNMP protocol. Diagnostic information is displayed on the intuitive screen forms of ENMI-6. Common error notification can be transferred to external systems through digital output.