Narrow Matrix Expansion; Wide Matrix Expansion - Keithley 7077 Instruction Manual

Operation
As shown in Figure 2-7, the backplane disconnect jumper is
positioned to connect the matrix row to the next higher and
lower switching matrix slot. To isolate the matrix row from
the backplane, remove the jumper. Refer to the Model 707
Switching Matrix Instruction Manual for more information
on configuring the Model 707 Switching Matrix backplane
disconnect jumpers.
The backplane used in the Model 707 and
708 Switching Matrices for the Model
7073 Matrix Cards is not used by any oth-
er switching matrix cards. This isolates
any Model 7077 Matrix Cards connected
through the backplane of a Model 707/708
Switching Matrix from Model 7073 Ma-
trix Cards.

2.5.2 Narrow matrix expansion

When shipped from the factory, the jumpers on the card are
positioned to connect the rows into the backplane of a Model
707 or 708 Switching Matrix. Therefore, each Model 7077
card installed next to another Model 7077 in the switching
matrix extends the matrix by 12 columns (see Table 2-3). For
example, three cards installed in slots 1, 2, and 3 of the Mod-
el 707 will result in an 8 × 36 matrix. Figure 2-9 shows three
matrix cards installed in slots 1, 2, and 3. Cards must be in-
stalled in adjacent slots for the rows to be connected together.
Similarly, if a Model 708 Switching Matrix is externally ex-
panded (three Model 708s connected through the back-
plane), installing the Model 7077 Matrix Card in each would
result in an 8 × 36 matrix. Refer to paragraph 2.5.5 for infor-
mation on external mainframe matrix expansion for the
Model 708 Switching Matrix.
A
ROWS
H
Figure 2-9
Narrow matrix expansion (8 × 36)
2-8
NOTE
1
12
7077
(Slot 1)
Table 2-3
Narrow matrix expansion*
Installed matrix cards
1 card
2 cards
3 cards
4 cards
5 cards
6 cards**
* For the Model 707 Switching Matrix, backplane jumpers must
be in position 1 (refer to Model 707 Switching Matrix Instruc-
tion Manual), and cards must be installed with no empty slots
between them. This will keep the circuit through the backplane
serial link closed.
**Not applicable to the Model 708 Switching Matrix due to the
master/slave configuration having a maximum of five cards.

2.5.3 Wide matrix expansion

Configure wide matrices by connecting the columns of one
Model 7077 card to the columns of another Model 7077
card. An example of a wide matrix (16 × 12) is shown in Fig-
ure 2-10. Note that the rows of the two cards are isolated
from each other. Isolate each matrix card's rows by removing
jumpers to isolate each card.
The most convenient method for connecting columns of two
cards together is to use 12 BNC to BNC cables (Keithley
Model 7051) and 12 BNC "T" female, male, female adapters
(Pomona Model 3285). Connect the "T" adapters to the 12
columns of one card, and then connect the BNC cables from
the adapters to the columns of the other card. The extra BNC
connector on each adapter will then allow column connec-
tion to instrumentation or DUTs.
COLUMNS
13 24
7077
(Slot 2)
Resulting matrix
8 × 12
8 × 24
8 × 36
8 × 48
8 × 60
8 × 72
25 36
7077
(Slot 3)