Keithley 7709 User manual

Model 7709
User’s Guide
PA-771 Rev. B / 8-03
A GREATER MEASURE OF CONFIDENCE

Safety Precautions
The following safety precautions should be observed before using
this product and any associated instrumentation. Although some in-
struments and accessories would normally be used with non-haz-
ardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recog-
nize shock hazards and are familiar with the safety precautions re-
quired to avoid possible injury. Read and follow all installation,
operation, and maintenance information carefully before using the
product. Refer to the manual for complete product specifications.
If the product is used in a manner not specified, the protection pro-
vided by the product may be impaired.
The types of product users are:
Responsible body is the individual or group responsible for the use
and maintenance of equipment, for ensuring that the equipment is
operated within its specifications and operating limits, and for en-
suring that operators are adequately trained.
Operators use the product for its intended function. They must be
trained in electrical safety procedures and proper use of the instru-
ment. They must be protected from electric shock and contact with
hazardous live circuits.
Maintenance personnel perform routine procedures on the product
to keep it operating properly, for example, setting the line voltage
or replacing consumable materials. Maintenance procedures are de-
scribed in the manual. The procedures explicitly state if the operator
may perform them. Otherwise, they should be performed only by
service personnel.
Service personnel are trained to work on live circuits, and perform
safe installations and repairs of products. Only properly trained ser-
vice personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that
are rated Measurement Category I and Measurement Category II, as
described in the International Electrotechnical Commission (IEC)
Standard IEC 60664. Most measurement, control, and data I/O sig-
nals are Measurement Category I and must not be directly connect-
ed to mains voltage or to voltage sources with high transient over-
voltages. Measurement Category II connections require protection
for high transient over-voltages often associated with local AC
mains connections. Assume all measurement, control, and data I/O
connections are for connection to Category I sources unless other-
wise marked or described in the Manual.
Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present. A good safety practice is to expect
that hazardous voltage is present in any unknown circuit before
measuring.
Operators of this product must be protected from electric shock at
all times. The responsible body must ensure that operators are pre-
vented access and/or insulated from every connection point. In
some cases, connections must be exposed to potential human con-
tact. Product operators in these circumstances must be trained to
protect themselves from the risk of electric shock. If the circuit is
capable of operating at or above 1000 volts, no conductive part of
the circuit may be exposed.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When con-
necting sources to switching cards, install protective devices to lim-
it fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connect-
ed to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.
When installing equipment where access to the main power cord is
restricted, such as rack mounting, a separate main input power dis-
connect device must be provided, in close proximity to the equip-
ment and within easy reach of the operator.
For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge
any capacitors before: connecting or disconnecting cables or jump-
ers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the com-
mon side of the circuit under test or power line (earth) ground. Always
make measurements with dry hands while standing on a dry, insulated
surface capable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety of the equip-
ment may be impaired.
Do not exceed the maximum signal levels of the instruments and ac-
cessories, as defined in the specifications and operating informa-
tion, and as shown on the instrument or test fixture panels, or
switching card.
When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.
Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is ap-
plied to the device under test. Safe operation requires the use of a
lid interlock.
5/03

If a screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.
The symbol on an instrument indicates that the user should re-
fer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or mea-
sure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.
The symbol indicates a connection terminal to the equipment
frame.
The WARNING heading in a manual explains dangers that might
result in personal injury or death. Always read the associated infor-
mation very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and
all test cables.
To maintain protection from electric shock and fire, replacement
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Keithley Instru-
ments. Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that se-
lected parts should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument. Products that consist of a circuit board with no
case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to in-
structions. If the board becomes contaminated and operation is af-
fected, the board should be returned to the factory for proper
cleaning/servicing.
!

PA-771 Rev. B./ 8-03
Model 7709
User’s Guide
Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139
[phone]
Fax: [phone]
www.keithley.com
The information in this section is organized as follows:
•Card configuration – schematic on page 2.
•Rows 1 and 2 on page 4.
•Rows 3 through 6 on page 5.
•Matrix expansion on page 6.
•Basic matrix column expansion on page 6.
•Daisy-chaining matrix rows on page 8.
•Connections and wiring on page 9.
•D-shell connectors on page 10.
•Wiring on page 11.
•Row daisy-chain connections on page 15.
•Typical DUT connections on page 18.
•Connection log on page 21.
•Operation on page 22.
•Channel assignments on page 22.
•System channel operation on page 22.
•Multiple channel operation on page 24.
•Service on page 24.
•Performance verification on page 24.
•Replaceable parts on page 24.
•Specifications on page 29.

2
Introduction
The Model 7709 is a 2-pole, 6 × 8 matrix card with the following features:
• Two rows (1 and 2) connected to the backplane of the Model 27xx for 2-wire or 4-wire Ω measurements
(automatically pairs switches for four wire measurements).
• 50-pin female D-shell connector (DB-50) for matrix rows and columns.
• 25-pin female D-shell connector (DB-25) for matrix expansion. Used to “daisy-chain” matrix rows to the rows of a
second Model 7709.
• Temperature applications (RTD or thermistor).
NOTE The 7709 module can be used with Keithley Models 2700, 2701, and 2750. All references to the
Model 27xx apply to the Models 2700, 2701, and 2750.
WARNING Before operating the Model 27xx with an accessory card, verify that the card is properly
installed and the mounting screws are tightly fastened. If the mounting screws are not
properly connected, an electrical shock hazard may be present.
Card configuration – schematic
Figure 1 shows a simplified diagram of the Model 7709 matrix module. The matrix consists of 48 crosspoints. Each crosspoint
channel is a 2-pole switch that, when closed, connects a row to a column. As shown in Figure 1, closing channel 43 connects
Row 6 to Column 3.
Two switches (channels 49 and 50) are used to connect Rows 1 and 2 to the backplane of the Model 27xx multimeter. When
channel 50 is closed, Row 1 is connected to the INPUT of the DMM. When channel 49 is closed, Row 2 is connected to
SENSE of the DMM.
Devices under test (DUT) are to be connected to the matrix columns. Using 2-wire connections, up to eight DUT can be tested.
For 4-wire connections, up to four DUT can be tested. Rows 3 through 6 can be used to add one or more external sources to the
test system.
Although the Model 7709 relays are the latching type (relays hold their state even after power has been removed), all relay
states are set to open a few seconds after either a power cycle or an *RST command is issued.

3
Figure 1
Simplified schematic for Model 7709
HI
LO Input
HI
LO Sense
9 10111213 141516
17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32
33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48
50
49
12345 678
12345 678
Columns
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
HI
LO
Rows
1
2
3
4
5
6
HI
LO
HI LO
Matrix
Crosspoint
(1 of 48)
To DMM
Backplane
HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
Ch 43
Row 6
Column 3

4
Rows 1 and 2
System channel operation ( ROUT:CLOS command) is used to close Rows 1 and 2 channels to connect a DUT to the DMM.
With a 2-wire function selected (i.e., DCV), system channels 1 through 8 can be closed. When one of these channels is closed,
channel 50 automatically closes to connect Row 1 to the DMM Input. Figure 2 shows a DUT connected to column 3 of the
matrix. Closing system channel 3 connects the DUT to the DMM.
With a 4-wire function selected (i.e., Ω 4), system channels 1 through 4 can be closed. These four channels are paired to chan-
nels 13 through 16 (channel 1 paired to channel 13, channel 2 paired to channel 14, and so on). When one of these system
channels is closed, its paired channel, and channels 49 and 50 also close to connect the DUT to the DMM. As shown in
Figure 3, closing system channel 3 also closes channels 15, 49, and 50 to connect the DUT to the DMM.
Figure 2
2-wire DUT measurements using Model 27xx DMM
Figure 3
4-wire DUT measurements using Model 27xx DMM
HI
LO Input
HI
LO Sense
910 11 12 13 14 15 16
50
49
12345678
HI
LO
HI
LO
Col 1
HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8
Row 1
Row 2
DUT
DMM*
System channel 3 closed to connect DUT to DMM Input. Note that
backplane channel 50 closes automatically.
* 2-wire function
selected.
HI
LO Input
HI
LO Sense
910 11 12 13 14 15 16
50
49
12345678
HI
LO
HI
LO
Col 1
HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8
Row 1
Row 2
DUT
DMM*
System channel 3 closed to connect DUT to DMM Input and Sense.
Note that paired channel 15, and backplane channels 49 and 50
close automatically.
* 4-wire function
selected.

5
Rows 3 through 6
As shown in Figure 1, channels 17 through 48 are the channels for Rows 3 through 6. These channels can only be closed using
multiple channel operation ( ROUT:MULT:CLOS command). For system channel operation, these channels are invalid (cannot
be closed).
WARNING Multiple channel operation should only be performed by experienced test engineers who
recognize the dangers associated with multiple channel closures.
CAUTION When closing multiple channels, it is possible to connect incompatible test equipment
and/or DUTs causing high currents to flow. This can cause serious damage to test equip-
ment and DUTs.
Rows 3 through 6 are used to connect one or more external sources to the test system. An external source is typically used to
power DUT. To prevent overloading of the external source, each DUT can be powered separately. An example of this is shown
in Figure 4. The external source is connected to Row 3 and the power cables for the two DUTs are connected to Columns 1 and
2.
As shown in Figure 4, DUT 1 is tested by closing system channel 3 and multiple channel 17. To test DUT 2, the following
sequence would be used:
1. Open multiple channel 17 to remove power from DUT 1.
2. Close multiple channel 18 to apply power to DUT 2.
3. Close system channel 4 to connect DUT 2 to the DMM (channel 3 opens automatically).
Figure 4
Adding an external source to the test system
HI
LO Input
HI
LO Sense
910 11 12 13 14 15 16
50
49
12345678
HI
LO
Row 1
DUT
1
DMM*
Col 1
HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8
HI
LO
Row 2
HI
LO
Row 3
External
Source
DUT
2
Multiple channel 17 closed to power DUT 1.
System channel 3 closed to connect DUT 1 to DMM Input.
17 18 19 20 21 22 23 24 *2-wire
function
selected.

6
Matrix expansion
Basic matrix column expansion
The number of columns in a matrix test system can be increased by simply installing another Model 7709 in the mainframe.
For the Model 2700/2701 mainframe, adding a second Model 7709 increases the total number of columns to 16. For the
Model 2750, five installed Model 7709s provide 40 columns for DUT.
Figure 5 shows a two matrix module system to test 16 DUT. It is similar to the one in Figure 2 except that the second card
allows eight more DUT to be tested. As shown, system channel 3 of the second module is closed to connect DUT 11 to the
DMM Input.
Figure 5
Two matrix module test system
Figure 6 shows a two matrix module system that uses an external source. It is similar to the one in Figure 4 except that it allows
more DUT to be tested. The first matrix module is used to route the external source to the DUT, while the second module is
used to measure the DUT.
As shown in Figure 6, DUT 1 is tested by closing multiple channel 25 and system channel 1 of the two respective modules.
The other DUT is tested in a similar manner. DUT 2 is tested with channels 26 and 2 closed, DUT 3 is tested with channels 27
and 3 closed, and so on.
18
7709
#1
DMM
Input
DUT
8
DUT
7
DUT
6
DUT
5
DUT
4
DUT
1
DUT
2
DUT
3
8
7
6
5
4
3
2
1
System channel 3 of module #2 closed to connect DUT 11 to DMM Input.
Note: Each signal path shown in this illustration is actually a two conductor
path pair (HI and LO).
18
7709
#2
DMM
Input
DUT
16
DUT
15
DUT
14
DUT
13
DUT
12
DUT
9
DUT
10
DUT
11
8
7
6
5
4
3
2
1
1
6
1
6

7
Figure 6
Two matrix module test system using an external source
1
61818
7709
#1
7709
#2
External
Source
DMM
Input
DUT
8
DUT
7
DUT
6
DUT
5
DUT
4
DUT
1
DUT
2
DUT
3
32
87654321
31
3029
2827
26
25
Multiple channel 25 of module #1 closed to power DUT 1.
System channel 1 of module #2 closed to connect DUT 1 to DMM Input.
Note: Each signal path shown in this illustration is actually a two conductor
path pair (HI and LO).
1
6

8
Daisy-chaining matrix rows
In order to route one or more external sources to other matrix modules, the rows of the modules must be daisy-chained.
External cabling is used to connect the rows of the matrix modules together.
Figure 7 shows examples of row daisy-chained matrix systems. For the 6 × 16 matrix, daisy-chaining the two matrix modules
allows the external source to be routed to the second module. For the 6 × 40 matrix, daisy-chaining the five matrix modules
allows the external source to be routed to any of the 40 columns in the system.
NOTE Techniques to daisy-chain rows are explained in “Connections and wiring.”
Figure 7
Daisy-chained matrix modules
1
61818
(1) (8) (9) (16)
7709
#1 7709
#2 (17) (24)
7709
#3 (25) (32)
7709
#4 (33) (40)
7709
#5
181818
1
61818
(1) (8) (9) (16)
7709
#1 7709
#2
External
Source
6 ×16 Matrix:
6 ×40 Matrix (Model 2750):
6
30
Multiple channel 30 of module #2 closed
to connect external source to column 6 of
module #2.
28
4
Multiple channel 28 of module #5 closed to connect external
source to column 4 of module #5.
Notes:
The matrices in this illustration are simplified to show external source
connections to other matrix modules. Connections to the DMM are
not shown.
Each signal path shown in this illustration is actually a two conductor
path pair (HI and LO).
External
Source

9
Connections and wiring
WARNING The following information is intended for qualified service personnel. Do not make
matrix module connections unless qualified to do so.
To prevent electric shock that could result in serious injury or death, adhere to following
safety precautions:
• Before removing or installing a matrix module in the mainframe, make sure the mainframe is
turned off and disconnected from line power.
• Before making or breaking connections, make sure power is removed from all external
circuitry.
• Do not connect signals that may exceed the maximum specifications of the Model 7709 or
external wiring. Specifications for the Model 7709 are provided at the end of this section.
WARNING A connector cover must be installed on unused connectors. This includes unused con-
nectors on the Model 7709s and unused row daisy-chain cable connectors. Use two #4-40
screws and nuts to secure a connector cover to a cable connector.

10
D-shell connectors
Figure 8 shows the pin numbers for the Model 7709 rear panel connectors. The 50-pin D-shell is used for DUT and external
source connections. The 25-pin D-shell is used to daisy-chain the matrix rows of two or more Model 7709s. Terminal
identification for the female connector pins are contained in Table 1.
Figure 8
Rear view – Model 7709 D-shell pinouts
Table 1
D-shell pin identification
50-pin D-shell
(DB-50)
25-pin D-shell
(DB-25)
Pin
Matrix
terminal Pin
Matrix
terminal Pin
Matrix
terminal
1 Row 1 Hi 25 Col 2 Lo 1 Row 1 Hi
2 Row 2 Lo 26 Col 3 Hi 2 Row 2 Hi
3 — 27 Col 4 Lo 3 Row 3 Hi
4 Row 4 Lo 28 Col 5 Hi 4 —
5 — 29 Col 6 Lo 5 Row 4 Hi
6 Row 6 Lo 30 Col 7 Hi 6 Row 5 Hi
7 — 31 Col 8 Lo 7 —
8 Col 1 Lo 32, 33 — 8 Row 6 Hi
9 — 34 Row 1 Lo 9-13 —
10 Col 3 Lo 35 Row 3 Hi 14 Row 1 Lo
11 — 36 — 15 Row 2 Lo
12 Col 5 Lo 37 Row 5 Hi 16 Row 3 Lo
13 — 38-40 — 17 —
14 Col 7 Lo 41 Col 2 Hi 18 Row 4 Lo
15-17 — 42 — 19 Row 5 Lo
18 Row 2 Hi 43 Col 4 Hi 20 —
19 Row 3 Lo 44 — 21 Row 6 Lo
20 Row 4 Hi 45 Col 6 Hi 22-25 —
21 Row 5 Lo 46 —
22 Row 6 Hi 47 Col 8 Hi
23 — 48-50 —
24 Col 1 Hi
1
17
18
34
50
33
13 1
1425
50-Pin D-Shell Connector (Female) 25-Pin D-Shell Connector (Female)

11
Wiring
NOTE The Model 7709 is shipped with plastic connector covers installed on the D-shell connectors. Each
cover is secured to the connector by two screws. After removing a connector cover, retain it and
the screws for future use. Any unused D-shell connector must have the connector cover installed.
The Model 7709 is supplied with one 50-pin male IDC ribbon cable connector, and one 25-pin male IDC ribbon cable
connector. These ribbon cable connectors mate to the D-shell connectors of the switching module.
WARNING When using IDC ribbon cable connections, DO NOT exceed 42V anywhere in the test
system or at the front panel inputs of the Mo del 27xx. For higher voltage applications,
use larger wire (up to #20 AWG) and solder cup D-shell con nectors.
There are two connector kits that have connectors that can be used with the Model 7709:
• Model 7790 ribbon cable adapter kit — Contains one female DB-50, one male DB-50, and one male DB-25 IDC
ribbon cable connectors. The two male IDC connectors mate to the female connectors on the Model 7709.
• Model 7789 50/25-pin solder cup connector kit — Contains one male DB-50 and one male DB-25 solder cup
connectors. These connectors mate to the female connectors on the Model 7709.

12
DUT and external source connections
DUT and external sources are to be wired to a 50-pin male D-shell connector. An IDC D-shell ribbon cable connector or a D-
shell solder cup connector can be used.
IDC ribbon cable connections
WARNING When using IDC ribbon cable connections, DO NOT exceed 42V anywhere in the test
system or to the front panel inputs of the Model 27xx.
Connect an appropriate length of 50-conductor IDC ribbon cable to a 50-pin male D-shell IDC connector. Table 2 and Figure 9
provide terminal identification for the 50-pin ribbon cable connections.
The connector of the prepared ribbon cable assembly mates to the 50-pin D-shell connector of the Model 7790 as shown in
Figure 10. Make sure the connector cover for the 25-pin D-shell connector is installed if it is not going to be used.
Table 2
Terminal identification for 50-conductor IDC ribbon cable and 7709 DB-50 connector
Ribbon Cable*: Matrix DB-50 Ribbon Cable*: Matrix DB-50
Conductor Color Terminal Pin # Conductor Color Terminal Pin #
1 Brown Row 1 Hi 1 26 Blue — —
2 Red Row 1 Lo 34 27 Violet Col 3 Hi 26
3 Orange Row 2 Hi 18 28 Grey Col 3 Lo 10
4 Yellow Row 2 Lo 2 29 White Col 4 Hi 43
5 Green Row 3 Hi 35 30 Black Col 4 Lo 27
6 Blue Row 3 Lo 19 31 Brown — —
7 Violet — — 32 Red — —
8 Grey — — 33 Orange Col 5 Hi 28
9 White Row 4 Hi 20 34 Yellow Col 5 Lo 12
10 Black Row 4 Lo 4 35 Green Col 6 Hi 45
11 Brown Row 5 Hi 37 36 Blue Col 6 Lo 29
12 Red Row 5 Lo 21 37 Violet — —
13 Orange — — 38 Grey — —
14 Yellow — — 39 White Col 7 Hi 30
15 Green Row 6 Hi 22 40 Black Col 7 Lo 14
16 Blue Row 6 Lo 6 41 Brown Col 8 Hi 47
17 Violet — — 42 Red Col 8 Lo 31
18 Grey — — 43 Orange — —
19 White — — 44 Yellow — —
20 Black — — 45 Green — —
21 Brown Col 1 Hi 24 46 Blue — —
22 Red Col 1 Lo 8 47 Violet — —
23 Orange Col 2 Hi 41 48 Grey — —
24 Yellow Col 2 Lo 25 49 White — —
25 Green — — 50 Black — —
* 50-conductor IDC ribbon cable is available from Keithley.

13
Figure 9
Ribbon cable terminal identification
26 Blue
27 Violet 28 Grey
29 White HI Column 4
LO
30 Black
HI Column 3
LO
31 Brown 32 Red
33 Orange 34 Yellow
HI Column 5
LO
35 Green HI Column 6
LO
36 Blue
37 Violet
38 Grey
39 White HI Column 7
LO
40 Black
41 Brown HI Column 8
LO
42 Red
43 Orange
44 Yellow
45 Green
46 Blue
47 Violet
48 Grey
49 White 50 Black
1 Brown HI Row 1
LO
2 Red
3 Orange 4 Yellow HI Row 2
LO
HI Row 3
LO
6 Blue
7 Violet
8 Grey
9 White HI Row 4
LO
10 Black
11 Brown HI Row 5
LO
12 Red
13 Orange
14 Yellow
15 Green 16 Blue
17 Violet
18 Grey
19 White
20 Black
21 Brown 22 Red
23 Orange 24 Yellow
25 Green
HI Row 6
LO
5 Green
IDC Ribbon Cable —50-Conductor
50-Pin D-Shell
Male IDC
HI Column 1
LO
HI Column 2
LO

14
Figure 10
Connecting ribbon cable assembly
Solder cup cable connections
Make all connections to a 50-pin D-shell male solder cup connector using the correct wire size up to 20 AWG. Terminal
identification for the 50-pin D-shell connector is provided in Table 1 and Table 2. Make sure to add supplementary insulation
around the harness for voltages above 42V peak (Figure 11).
WARNING All solder cup wiring must be rated for the maximum voltage in the system. For
example, if 1000V is applied to the front terminals of the DMM, all matrix module
wiring must be rated for 1000V.
The connector cover for the 25-pin D-shell connector on the Model 7709 must be installed
if it is not going to be used. If the connector is left open, an electrical shock hazard may
be present.
Figure 11
Connecting solder cup cable assembly
Install plastic cover
over unused connector
using two #4-40 screws.
KEITHLEY
CONNECTOR COVER
Warning: When using ribbon cable,
DO NOT exceed 42 volts
anywhere in the test system
or at the front panel inputs
of the Model 2700/2750.
Supplementary
Insulation
Install plastic cover
over unused connector
using two #4-40 screws.
KEITHLEY
CONNECTOR COVER

15
Row daisy-chain connections
Row daisy-chain ribbon cable assembly
WARNING When using IDC ribbon cable, DO NOT exceed 42V anywhere in the test system or to
the front panel inputs of the Model 27xx.
A convenient method to daisy-chain the rows of two or more Model 7709s, is to use a 25-conductor ribbon cable assembly
with IDC ribbon cable connectors attached to it. For the Model 2700/2701, a two-connector ribbon cable assembly will daisy-
chain two matrix modules. For the Model 2750, a five-connector ribbon cable will daisy-chain five matrix modules.
Refer to Figure 12 and perform the following steps to build a row of daisy-chain cable:
1. Start with an appropriate length of 25-conductor IDC ribbon cable. For the Model 2700/2701, a 3 ½ ” length of cable is need-
ed. For the Model 2750, a 20 ¼ ” length is needed.
2. Mark the locations for the IDC connectors on the ribbon cable.
3. Starting at the left end of the cable, attach an IDC connector.
Figure 12
Row daisy-chain ribbon cable assembly
Model 2700/2701:
Model 2750:
25 Conductor IDC Ribbon Cable (KI part #15025):
Model 2700/2701  .5 inch length required.
Model 2750  20.25 length required.
25-pin Male D-shell IDC Connector:
Model 2700/2701  Two connectors required.
Model 2750  Five connectors required.
Required Parts:
Brown
Insulator
Brown
Insulator
2-1/8 in.
20-1/4 in.
2-1/8 in. 2-1/8 in. 5/8 in.
2-1/8 in.
-1/2 in.
11- /8 in.
5/8 in.

16
4. Route the cable over the back side of the connector and install the strain relief for the connector. Make sure the cable is
firmly clamped to the connector body. Figure 13 shows how the cable is routed through the strain reliefs of the connectors.
5. Repeat steps 3 and 4 to attach the rest of the IDC connectors at the marked locations.
Figure 14 shows the row of daisy-chain ribbon cables connected to the 25-pin D-shell connectors of the Model 7709s. Matrix
terminal identification for the 25-conductor ribbon cable is provided in Table 3.
WARNING A connector cover must be installed on unused connectors. This includes unused con-
nectors on the Model 7709s and unused row daisy-chain cable connectors. Use two #4-40
screws and nuts to secure a connector cover to a cable connector.
Figure 13
Row daisy-chain ribbon cable routing
Strain Relief
Male 25-Pin
IDC Connector
Ribbon Cable
Side View of Cable Assemblies:

17
Figure 14
Connecting row daisy-chain cables
Table 3
Terminal identification for 25-conductor IDC ribbon cable and 7709 DB-25 connector
Ribbon Cable*: Matrix DB-25 Ribbon Cable*: Matrix DB-25
Conductor Color Terminal Pin # Conductor Color Terminal Pin #
1 Brown Row 1 Hi 1 14 Yellow — —
2 Red Row 1 Lo 14 15 Green Row 6 Hi 8
3 Orange Row 2 Hi 2 16 Blue Row 6 Lo 21
4 Yellow Row 2 Lo 15 17 Violet — —
5 Green Row 3 Hi 3 18 Grey — —
6 Blue Row 3 Lo 16 19 White — —
7 Violet — — 20 Black — —
8 Grey — — 21 Brown — —
9 White Row 4 Hi 5 22 Red — —
10 Black Row 4 Lo 18 23 Orange — —
11 Brown Row 5 Hi 6 24 Yellow — —
12 Red Row 5 Lo 19 25 Green — —
13 Orange — —
*25-conductor IDC ribbon cable is available from Keithley, Part #15025.
7709
Slot 1
7709
Slot 2
7709
Slot 4
7709
Slot 5
7709
Slot
Rows 1-6
Columns 1-8
Columns 9-16
Columns 17-24
Columns 18- 2
Columns -40
Model 2750
7709
Slot 1
7709
Slot 2
Rows 1-6
Columns 1-8
Columns 9-16
Model 2700/2701
Row Daisy-Chain
Cable
Row Daisy-Chain
Cable