SEL Mirrored Bits® Communications

SEL MIRRORED BITS^® Communications

Low-Cost Relay-To-Relay Logic Communication

Features and Benefits

Eliminates expensive external communications equipment, wiring, and maintenance.
Provides EIGHT user-assignable "virtual" inputs and outputs.
Simplifies and consolidates pilot protection schemes.
Connects directly to serial communications channel.
Provides comprehensive channel performance data.

Technology Overview

MIRRORED BITS^® communications is an innovative, low-cost, relay-to-relay communications technology that exchanges the status of eight internal logic points called MIRRORED BITS, encoded in a digital message, from one device to another. This patented technology opens the door to numerous protection, control, and monitoring applications that would otherwise require more expensive external communications equipment wired through contacts and control inputs. Applications for MIRRORED BITS communications include line protection pilot schemes, remote device control and monitoring, relay crosstripping, and more.

Transmit MIRRORED BITS to Receive Example

Operational Overview

The received MIRRORED BITS (RMBs) of one relay follow the status, or "mirror" the status, of the respective transmit MIRRORED BITS (TMBs) sent from the other relay. Each of the relays in the scheme repeatedly sends and receives the digital message while continually monitoring and checking the received message integrity. An internal monitoring point asserts when a good signal is received and deasserts immediately upon detection of a bad message. Other elements are also available for channel alarming and availability.

Field-Proven Technology

Join other SEL customers who have used MIRRORED BITS communications since 1996 for fast, secure, and dependable communications. For technical and application information on MIRRORED BITS communications, use the following links:

Handheld SEL-4388 MIRRORED BITS^® Tester

The SEL-4388 gives engineers and technicians the power to accelerate commissioning and bench testing, and to improve cable identification, training, and maintenance. Learn More >>

MIRRORED BITS communications is a standard feature in the following products:

Line Protection, Automation, and Monitoring

Distribution and Feeder Protection, Automation, and Monitoring

Bay, Bus, and Transformer Protection, Automation, and Monitoring

Motor Protection, Automation, and Monitoring

SEL-710 Motor Protection Relay

Metering

SEL-734 Revenue Meter

Automation and SCADA

Testing

SEL products that aid in the implementation of this technology are:

2350 NE Hopkins Court - Pullman, WA 99163 – USA
Phone: +1.509.332.1890 - Fax: +1.509.332.7990