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OPERATION
WARNING
To avoid electrical shock which could result in
iniurv or death. make sure
all
Dower is off and
&r&d
energy in external ciffi&try Is dischag-
ed before making any connections to the matrix
card.
CAUTION
Contamination will degrade the Performance of
tha matrix card. To avold contamination,
always
grasp the card by the handle and side edges.
Do not
touch the edge
connectors
of the card,
and do not touch the board surfaces or com-
ponents. On "rack and
panel" connectors
and
quick disconnect termlnal blocks, do not touch
areas adjacent to the electrical contacts.
2.5.1 Connections
Using Mass
Terminated
Cable (Model 70784TC)
The Model 7W78-MTC is a 36 conductor
cable terminated
with a "rack and panel" plug on each end. This cable is
used to connect the "COLUMNS"
or "ROWS" receptacle
on the rear panel of the card to external instrumentation
and test circuits. Figure 2-8 shows how two cables can be
used to connect rows and columns of the matrix card to
external "rack and panel" receptacles. The external recep
Lades can then be hard wired to other connectors or wired
directly to instrumentation
and DUTs.
Use the following
procedure
to connect the Model 7078
M'K
cable to the matrix card:
1. Install the matrix card in the Model 707 mainfrane
as
explained
in paragraph
2.3.
2. Place the plug of the cable on the appropriate
"rack and
panel" receptacle such that the large diameter keying
pin of the plug aligns with the large keyway of the recep
tade (see Figure 2-9).
3. Using a slotted screwdriver,
turn the locking
screw
clockwise until the plug is fully mated to the receptacle.
The same basic procedure
applies for connecting
the
cable plug to an external receptacle.
Receptade wuing
"Rack and panel" receptacles (Model 7UiSMTR) along with
recommended installation
tools are available from Keithley
(see Table 2-2). Perform the following
steps to wire a "rack
and panel" receptacle.
1. Remove 118" of insulation
from the wires that are to be
connected to the receptacle.
2. Using the Model 7U7SHcT crimping tool, connect a wire
cnmp tail to each of the wires.
3. Figure Z-10 provides contact identification
for "ROWS"
and "COLUMNS"
receptacles. Using this ilh~stration as
a guide, insert the wire crimp tails into the receptacle.
use the Model Xi78 CIT insertion tool to push each wire
crimp tail completely
into the receptacle.
Modified
Mass Terminated
Cable
Another way to use the Model 7UiSMTC cable is to remove
one of the plugs. Cutting the cable in half will provide hvo
10 foot cables. Each cable can then be mated to the "ROWS"
or "COLUMNS"
receptacle (see Figure 2-11). The wire end
of each cable can then be wired to another connector or
wired directly to instrumentation
or DUTs. The cable con-
tains twelve bundles of wires each of which corresponds
to a row or column. Each bundle contains three wires; a
bare wire (guard) and hvo insulated wires that have a uni-
que color combination
for identification
purposes. Table
2-3 provides the color combinations
for each bundle. For
example, with the cable connected to the "ROWS" recep-
tacle of the matrix card, Row E can be identified by locating
the bundle that has a red insulated
wire (H) and a blue
insulated
wire (L). The bare wire in the bundle is guard
G).
NOTE
If another "rack and panel" plug is to be attach-
ed to the unterminated
end of the cable, refer to
the connection
procedure
in paragraph
2.5.3.
The outer side of the foil shield is inslulated
while the in-
ner wrapping
is conductive (guard). When the cable is cut,
it is likely that the conductive
side of the bundle wrapp-
ing will become exposed. Thus, each bundle,
as well as
each bare wire, should be insulated
as follows:
1. Place a length of Teflona
tubing over each bare wire.
2. Place a length of shrink tubing over the bundle such
that the frayed end of the bundle wrapping
and part
of the Teflon@ tubing is covered.
3. Heat the shrink tubing.
2-9
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