GE LPS-O, Инструкция по эксплуатации

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LPS-O Line Protection System GE Power Management
1.7 SELF-TEST FEATURES 1 PRODUCT DESCRIPTION
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1.7 SELF-TEST FEATURES 1.7.1 START-UP SELF-TESTS
The most comprehensive testing of the LPS-O is performed during power-up. Since the LPS-O is not engaged
in any protection activities at that time, tests (such as RAM tests) that would normally disrupt run-time process-
ing are performed.
Both processors participate in the start-up self-testing. The processors communicate their results to each other
so that any failures can be reported and to ensure each processor successfully completes its assigned self-
tests before the LPS-O begins protection activity.
During power-up, both microprocessors perform start-up self-tests on their associated hardware (including
Flash Memory, EPROM, local RAM, shared RAM, interrupt controller, timer chip, serial I/O ports, nonvolatile
memory, analog and digital I/O circuitry, and Keypad/LCD Display hardware). In addition, the LPS-O verifies
that the PROM version numbers on both processor boards are compatible and the Model Number stored in
nonvolatile memory agrees with the LPS-O configuration. The components tested at start-up are listed in Table
9–1: COMPONENTS TESTED DURING START-UP TESTS on page 9–2
.
In most cases, if any critical self-test failure is detected, the LPS-O discontinues start-up and does not reset. It
attempts to store the LPS-O status and to initialize the KEYPAD/LCD DISPLAY and remote communications
hardware/software for communicating the status. The critical alarm output is energized.
If no failures are detected, the LPS-O completes initialization of its hardware and software. This includes read-
ing information from the serial non-volatile RAM (NVRAM) in the magnetics module, stored during the manu-
facturing process, to determine the relay current rating (1 A or 5 A). Next, the i960 processor enables the
outputs. As the final step, the LPS-O checks the results of all tests to determine whether to turn on the green
status LED on the front panel.
The start-up procedure takes approximately one minute. As soon as the i960 CPU successfully completes its
PROM test and initializes the display hardware, the message INITIALIZING appears on the display. When all
LPS-O initialization is completed satisfactorily, the LPS-O begins acquiring and processing data.
1.7.2 RUN-TIME SELF-TESTS
Both of the processors have idle time when the LPS-O is not performing fault or post-fault processing. During
this idle time, each processor performs background self-tests that do not interfere with the foreground tasks’
use of serial and parallel ports and that do not inhibit interrupts to any processor. If any background self-test
fails, the test is repeated. For a component to be declared as failed, the test must fail three consecutive times.
In the case of most critical failures, the LPS-O forces a reset to attempt to get the failed component working
again.
The LPS-O is able to distinguish between a start-up (power-up) and a reset caused automatically by a LPS-O
malfunction. The reset is a fault-tolerant feature of the LPS-O; it is performed as an attempt to resume opera-
tion after an intermittent failure. The reset activities are identical to the start-up activities except that not all
start-up self-tests are performed. If the reset was caused by failure of a specific background self-test, then only
the start-up self-tests associated with that same hardware are performed.
A reset is not reported by the LPS-O. If the reset is successful, no failure status is recorded and the critical
alarm output is not energized. However, during the reset procedure, the red LED on the front panel is lit and a
failure code may appear on the display. Therefore, if the reset is not successful, the processor board is shut
down, leaving the error information displayed on the LCD screen. Refer to Section 9.3.7: SERVICE SYSTEM
STATUS FAILURES on page 9–6
for a complete list of error messages . To prevent continual resets in the case
of a solid failure, both hardware and software permit only four resets in a one-hour period. On the fifth reset,
the LPS-O does not initialize, but attempts to initialize the display, communications, and the critical-alarm out-
put, as in the case of a start-up with a critical self-test failure. The reset procedure takes approximately one
second, depending upon which start-up self-tests are to be run.