Self-Test Features; Start-Up Self-Tests; Run-Time Self-Tests - GE LPS-D Instruction Manual

1.7 SELF-TEST FEATURES

1.7 SELF-TEST FEATURES
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The most comprehensive testing of the LPS-D is performed during a power-up. Since the LPS-D is not per-
forming any protection activities at that time, tests (such as RAM tests) that would be disruptive to run-time pro-
cessing 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 so that each processor successfully completes its assigned self-tests
before the LPS-D begins protection activity.
During power-up, both microprocessors perform start-up self-tests on its 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-D verifies that the
PROM version numbers on both processor boards are compatible, and that the model number stored in non-
volatile memory agrees with the unit's 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-D discontinues start-up and does not reset. It
attempts to store the LPS-D status and initialize the KEYPAD/LCD DISPLAY and remote communications
hardware/software to communicating its status. The critical alarm output is energized.
If no failures are detected, the LPS-D completes initialization of its hardware and software; this includes read-
ing information from the serial non-volatile RAM (NVRAM) in the magnetic module, stored during the manufac-
turing process, to determine the current rating of the magnetic in the unit (1 A or 5 A). Next, the i960 processor
enables the outputs. As the final step, the LPS-D checks the results of all the 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-D initialization is completed satisfactorily the LPS-D begins acquiring and processing data.
Both of the processors have idle time when the LPS-D 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-D forces a reset to attempt to get the failed component working
again.
The LPS-D is able to distinguish between a start-up (power-up) and a reset caused automatically by an LPS-D
malfunction. The reset is a fault-tolerant feature of the LPS-D; 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-D. 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 on the display. Refer to Section 9.2.7: SERVICE SYSTEM STATUS FAIL-
URES on page 9–5 . To prevent continual resets in the case of a solid failure, both hardware and software per-
mit only four resets in a one-hour period. On the fifth reset, the LPS-D does not initialize, but attempts to
initialize the display, communications, and the critical-alarm output, 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.
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LPS-D Line Protection System
1 PRODUCT DESCRIPTION

1.7.1 START-UP SELF-TESTS

1.7.2 RUN-TIME SELF-TESTS

GE Power Management