Reliable and secure teleprotection schemes - direct implementation in main protection

The paper discusses a new technique which permits end to end channel schemes to be configured, without the need to purchase costly discrete carrier equipment. The relays connect directly to MODEM or multiplexed links, via an EIA RS232 interface on the rear of each relay in the scheme. The new feature allows high performance permissive and blocking unit protection to be configured. Intertripping is supported too, with channel health monitoring and cyclic redundancy checks (CRC) on the received data for maximum message security.