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⟦0317c9cd8⟧ Wang Wps File
Length: 6842 (0x1aba)
Types: Wang Wps File
Notes: testfilosofi brev SHAPE
Names: »0436A «
Derivation
└─⟦0cbd6095b⟧ Bits:30006077 8" Wang WCS floppy, CR 0034A
└─ ⟦this⟧ »0436A «
WangText
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1981-01-21 gj/vhn
to: shnmo division
att.: mr. paul f. shey, contracting officer
cc.: lt. col. manfred stoltz, camps program manager
fm: christian rovsing a/s, denmark
gert jensen
our ref: cps/101/tlx/0172
subject: proposal for depot level test equipment
-----------------------------------------------------------------
ref: (a) Progress Review no. 2, june 19/20 1980 Minutes
of Meeting
In response to ref (a) action item cr hereby submits its
response.
1̲ ̲ ̲S̲C̲O̲P̲E̲
The scope of this paper is to propose an alternate
method to be used at the NATO Repair Depot on the CAMPS
Program.
2̲ ̲ ̲I̲N̲T̲R̲O̲D̲U̲C̲T̲I̲O̲N̲
The paper will briefly explain the test methods employed
by the CAMPS contractor in his factory, as well as
the possibilities for module test at a CAMPS installation.
Then the NATO Depot test philosophy will be discussed.
Finally the depot level test equipment proposed by
contractor will be described and a budgetary price
indicated.
3̲ ̲ ̲C̲O̲N̲T̲R̲A̲C̲T̲O̲R̲ ̲F̲A̲C̲T̲O̲R̲Y̲ ̲T̲E̲S̲T̲I̲N̲G̲
3.1 G̲E̲N̲E̲R̲A̲L̲
The printed circuit Boards (PCB) used on the CAMPS
program will be tested on at least two of the following
three test systems:
1. Generel Purpose Functional Tester (F L U K E)
2. In-Circuit Tester with "Forced Pulse Stimuli".
3. Dedicated CR 80 Test System.
3.2 G̲E̲N̲E̲R̲A̲L̲ ̲P̲U̲R̲P̲O̲S̲E̲ ̲F̲U̲N̲C̲T̲I̲O̲N̲A̲L̲ ̲T̲E̲S̲T̲
The FLUKE tester will test a number of the CR 80 modules
functionally to the extent these functions are accesable
from the edge connectors. The tester is capable of:
1) Performing a comparison with a known good PCB and
using a limited amount of functional stimuli programmed
for the PCB under test.
2) Performing test of PCB by means of external stimuli
and an expected output stored in the tester.
3.3 I̲N̲-̲C̲I̲R̲C̲U̲I̲T̲ ̲T̲E̲S̲T̲E̲R̲
As a result of the increase in circuit complexity of
the CR 80 PCB's the general purpose functional tester
is no longer sufficient as the only factory test equipment.
CR production department plans to purchase an in-circuit
tester to handle some of the more complex CR 80D microprocessor
based modules. This tester will have access to all
nodes of the circuit. By applying short duration, high
current pulses to the inputs of the various circuit
elements e.g. Flip Flops, gates, registers etc., the
output can be sampled and compared with a simple truth
table. The programmed input stimuli as well as the
truth table of the output is device dependent. Consequently,
programming is relatively simple compared with programming
a sequence of stimuli for a functionally complex circuit.
3.4 D̲E̲D̲I̲C̲A̲T̲E̲D̲ ̲C̲R̲ ̲8̲0̲ ̲T̲E̲S̲T̲ ̲S̲Y̲S̲T̲E̲M̲
In addition to the functional testers the production
Department is also using a "mini" CR 80 system as a
dedicated test system for PCB's with complex faults.
It is CR's experience that certain faults can only
be located when the PCB is exposed to the realtime
environment in an actual CR 80 computer. The test system
has a program library which will aid in trouble shooting
of hard-to-find faults. Test programs can easely be
altered or new ones generated to locate specific faults
in a particular board.
4̲ ̲ ̲S̲I̲T̲E̲ ̲T̲E̲S̲T̲I̲N̲G̲
The maintenance philosophy at the operational sites
is repair by module replacement. The off-line Maintenance
and Diagnostic Software supplied for each system will
be sufficiently exhaustive to ensure that the MTTR
will be below the maximum specified.
5̲ ̲ ̲D̲E̲P̲O̲T̲ ̲T̲E̲S̲T̲I̲N̲G̲,̲ ̲E̲X̲I̲S̲T̲I̲N̲G̲ ̲P̲H̲I̲L̲O̲S̲O̲P̲H̲Y̲
It is assumed that PCB fault finding to component level
is carried out at the NATO depot repair facility by
the use of a general purpose functional tester (GR
1795 HD). As part of the original proposal, contractor
offered as an option to generate test software to be
used for testing the CAMPS modules on the GR 1795 HD
tester.
Furthermore, it is assumed that Contractor produced
PCB's i.e. CAMPS central equipment modules, as well
as all subassemblies from peripherals i.e. VDU's printers,
discs etc. will be tested by the GR tester.
Assuming that the GR tester does not exercise the CAMPS
PCB's in real time some faults will not be identified
at the Depot. Depending on the extensiveness of the
test software these faults may amount to approx. 15
percent of the total PCB's failures. If these faults
are not found at the depot, the PCB in question will
be returned to an operational site as a spare containing
a not identified fault.
The CAMPS maintenance philosophy requires a verification
of the modules returned after repair. This verification
will take place in the off-line branch of the CAMPS
system. Since this effort will render the total installation
in a degreeded mode, a lengthy verification and possible
trouble shooting is not permissable.
Consequently, the depot repair system as described
above could lead to sites having spare CAMPS PCB's
with latent defects.
6̲ ̲ ̲D̲E̲P̲O̲T̲ ̲T̲E̲S̲T̲I̲N̲G̲,̲ ̲P̲R̲O̲P̲O̲S̲E̲D̲ ̲P̲H̲I̲L̲O̲S̲O̲P̲H̲Y̲
This section present two philosophies as alternatives
to the existing.
It should be emphasized, however, that the proposed
solutions will only cater for improving the testing
of CAMPS Central equipment subassemblies, i.e. contractor
produced. Subassemblies for peripherals will still
be tested by the GR tester or some other means provided
at the depot repair facility.
6.1 G̲R̲ ̲1̲7̲9̲5̲ ̲H̲D̲ ̲T̲E̲S̲T̲E̲R̲ ̲A̲N̲D̲ ̲C̲A̲M̲P̲S̲ ̲T̲E̲S̲T̲ ̲S̲Y̲S̲T̲E̲M̲
This philosophy assumes functional tests to be carried
out on all CAMPS PCB's using the GR 1795 HD Tester.
Associated test software will be produced by contractor
on request. Faults that can not be located by the GR
1795 HD tester will be found using the CAMPS test system.
The availability of the CAMPS Test System ensures that
the GR Tester does not have to cope with PCB's requiring
a time consuming fault finding process.
The CAMPS Test System will contain the Maintenance
and Diagnostic software normally available at a CAMPS
site in additon to special debugging software dedicated
to each PCB.
6.2 C̲A̲M̲P̲S̲ ̲T̲E̲S̲T̲ ̲S̲Y̲S̲T̲E̲M̲
This solution provides a CAMPS Test System only for
testing of CAMPS PCB's at the depot. The advantage
is that no effort needs to go into programming for
the GR tester, nor does the effort of testing CAMPS
PCB's add to the work-load of the GR Tester. Also the
cost of adaptors for the misc. CAMPS PCB's will be
saved.
7̲ ̲ ̲C̲O̲N̲C̲L̲U̲S̲I̲O̲N̲
The test philosophies described in this paper reflects
the rather limited knowledge Contractor has of the
NATO Depot Repair System contemplated for CAMPS.
It is felt that SHAPE and contractor should start a
dialog on this issue possibly based on the philosophies
described in this paper.
An estimated cost of a CAMPS Test Bed is D. kr. 1.200.000,-.
Based on further discussions with SHAPE contractor
will forward a technical and price proposal for a CAMPS
Test Bed.
