Keithley 7001, Инструкция по эксплуатации

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Maintenance
7-12
7.7.2 Non-volatile memory tests
The Model 7001 uses two kinds of non-volatile memo-
ry, a 24C16 EEPROM (Electrically Erasable Program-
mable Read-Only Memory) and battery backed RAM.
The EEPROM stores the IEEE-488 address, power-on
setup memories and other mainframe con
Þ guration
items. The battery backed RAM stores the scan list, for-
bidden channels, and relay card setup memories.
On initial power-up (or after replacing the battery or
memory parts) the Model 7001 may indicate a con
Þ gu-
ration error. Such messages should not occur after pro-
gramming setups.
The non-volatile memory test in this procedure stores
a CARD TYPE in the EEPROM and a SCAN LIST in the
battery backed RAM. Correct storage of these items af-
ter a few power line cycles provides a con
Þ dence test
that the non-volatile memory is functioning properly.
NOTE
This test instructed you to set the
CARD TYPE to “9990”. The CARD
TYPE setting will be changed if a
Model 701X card is inserted in a card
slot, and may result in an error mes-
sage. The test must be performed with
both card slots empty.
7.7.3 Built-in-tests
The following provides further details on the Built-In-
Tests. If these tests detect a fault, they will report the
following message at the conclusion of the test:
All tests complete *
Press ENTER to review or EXIT
To review the error, press ENTER. The display will
show the test which failed. For further information on
the failure, press INFO. Refer to the appropriate test
numbers below for further explanations. The following
discussions also suggest the most likely board failure
for each type of error. You may also
Þ nd it helpful to re-
fer to the schematic diagrams.
Test 100 (EPROM)
Failure of Test 100 suggests a digital board error.
All ROM bytes (except for the checksum bytes) are
read, a checksum is calculated and compared to the
stored checksum. A fault of this test indicates that one
or more ROM locations cannot be read properly. Check
U113 and associated logic.
Test 101 (RAM)
Failure of Test 101 suggests a digital board error.
This is an abbreviated version of power-on RAM test-
ing. Memory locations are written and read back. It is
highly unlikely that this test will ever fail --- a unit with
faulty RAM will probably fail the power-on memory
test or lock up intermittently. Check U110, U111, and
associated logic.
Test 102 (EEPROM)
Failure of Test 102 suggests a digital board error.
An attempt is made to read a byte of information from
the 24C16 con
Þ guration EEPROM (U106) and an ac-
knowledge signal is veri Þ ed. A fault in this test indi-
cates a problem with the 24C16 component or
associated signals. The test does not verify the validity
of con
Þ guration information stored in the EEPROM.
Check U106.
Test 103 (Digital I/O)
NOTE
With some Þ rmware revisions, the
digital output tests (103.1 through
103.4) will not pass if the built-in test
resistors are not present. (See para-
graph 4.9.1.)
Failure of Test 103 suggests a micro DIN board error.
Digital I/O on the Model 7001 consists of four open-
collector outputs, and one TTL-level input. Outputs
originate from the 68302 microprocessor PA4-PA7
(U107). PA4 drives OUT1, PA5 drives OUT2, etc. These
signals are buffered by a 2596 open collector driver
(U601 on the micro DIN board).
Digital input is buffered by protection circuitry (CR600,
CR609, R614, R615) and read by the 68302 at PB8.
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