Communication between PCM600 and the protection relay - Arc protection - Motor protection - Feeder protection - Back-up protection - Engineering Manual - REX610 Protection and control - 1.2.1 - IEC - ANSI - 03.05.2023

REX610 Engineering Manual

The communication between the protection relay and PCM600 is independent of the used communication protocol within the substation or to the NCC.

Each protection relay has an Ethernet interface connector on the rear and a USB interface connector on the front. Both connectors can be used for communication with PCM600.

Communication over Ethernet (rear port) is done using either IEC 61850 or FTP/FTPS. Communication over the front port USB is done over Media Transfer Protocol (MTP).

When an Ethernet-based station protocol is used for rear port communication, the same Ethernet port and IP address can be used for PCM600 communication.

Two basic variants have to be considered for the connection between PCM600 and the protection relay.

  • Direct point-to-point link between PCM600 and the protection relay's front port. When communicating over the front port USB, IP is not relevant and by default this is seen as 0.0.0.0.
  • Indirect link via station LAN or from remote via network
  1. If needed, the IP address for the protection relay is set.
  2. A PC or workstation is set up for a direct link (point-to-point), or the PC or workstation is connected to the LAN/WAN network.
  3. The protection relays' IP addresses in the PCM600 project are configured for each protection relay to match the IP addresses of the physical IEDs (rear port).
  4. Technical keys of the IEDs in PCM600 project are configured for each protection relay to match the technical keys of the physical IEDs.

For successful protection relay engineering and usage, check the workstation firewall TCP and UDP port configurations, especially for IEC 61850, FTP and MTP. Other protocols are not used for engineering and/or they are optional.

Table 1. Ports that must be open in the firewall for different protocols
Protocol TCP port
File Transfer Protocol (FTP and FTPS) 20, 21
IEC 61850 102
Simple Network Time Protocol (SNTP) 123
Modbus TCP 502

If there is an abrupt disconnection (removing of the communication cable) during an ongoing FTP/FTPS session, it takes 15–20 minutes for a fresh session to be successfully established.