Siemens 7SA511 Additional Functions and Features of the Relay, Secured Data Storage, Rear Port

7SA511 Line Protection Relay Chapter 2

2.5 Additional Functions and Features of the Relay

The rest of this chapter gives a general description about the remaining functions and features of the 7SA511 relay, as listed below:

Secured data storage

￿Serial data ports

Multiple parameter sets (optional)

2.5.1 Secured Data Storage

The 7SA511 relay provides all the data necessary to analyze the operational performance of the relay following a system fault. The recording functions, discussed below, are secured in case of a power interruption.

Real-time clock. A real-time clock with battery backup may be synchronized via a binary input or through a serial data port (see section 2.5.2). All events are recorded with a date and time tag.

Target history log. Operational records for the last three faults are recorded and stored in the relay’s memory. These records include the fault type, interrupted current, distance-to- fault, etc.

Target history for ungrounded systems. Relays with the optional isolated system ground fault detection function record the details for the last three ground faults in a

￿separate log.

Tripping statistics. For each pole of a circuit breaker, it is possible to record the cumulative total of tripping operations and interrupted current.

2.5.2 Serial Data Ports

A serial data port through which the relay can be programmed and operated is available on the operator panel. A second, optional port, used for data retrieval only, is available on the rear panel. In both cases, the data transmission protocol is in compliance with IEC 870-5.

Front Panel Port

The port on the operator panel is intended to be used with a locally attached personal computer (PC). It is accessible through the 25 pin connector on the operator panel. The attached PC can run DIGSI“or other appropriate software to communicate and exchange information with the relay. This interface is not electrically isolated from the monitored system and conforms to the EIA RS-232-C specification.

Rear Port

The optional port on the rear panel of the relay is intended for remote data retrieval by a substation control system. It is available as an optical fiber or hard-wired interface (relay models 7SA511*-**A5*-*B/C**). Consult the factory for details on the use of this feature.

July 27, 1995 2-13