Keithley 7707 User manual

Model 7707
User’s Guide
PA-770 Rev. B / 8-03
The Model 7707 can be used with Keithley
Models 2700, 2701, and 2750. All references
to the Model 27xx apply to the Models 2700,
2701, and 2750.
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-770 Rev. B/ 8-03
Model 7707
User’s Guide
Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139
[phone]
Fax: [phone]
www.keithley.com
The information in this packing list is organized as follows:
•Card configuration — schematic on page 2.
•Connections and wiring overview on page 4.
•D-shell connectors on page 4.
•Wiring on page 6.
•Connection log on page 11.
•Analog inputs on page 12.
•Operation on page 12.
•Typical analog input connections on page 14.
•Digital I/O on page 15.
•Digital outputs on page 15.
•Sink or source on page 16.
•Digital I/O protection on page 18.
•Output bit patterns on page 19.
•Setting digital outputs on page 22.
•Digital inputs on page 28.
•Input bit patterns on page 28.
•Reading digital inputs on page 30.
•CARD menu on page 42.
•Digital I/O command summary on page 45.
•Service on page 47.
•Performance verification on page 47.
•Replaceable parts on page 47.
•Specifications — 7707 Multiplexer-Digital I/O Module on page 52.
•Measurement considerations (digital outputs) on page 53.
NOTE The 7707 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.

2
Introduction
The Model 7707 is a 10-channel differential multiplexer card with the following features:
• 10 channels of analog input with 300V, 1A capacity; 60W, 125VA maximum.
• 32 digital input/output channels.
• 2-wire or 4-wire Ω measurement (automatically pairs switches for four wire measurements — n + 5).
• Temperature applications (RTD, thermistor).
• 50-pin male D-Shell connector (DB-50) for digital I/O channels 11 through 14.
• 25-pin female D-Shell connector (DB-25) for analog input channels 1 through 10.
WARNING Before operating the Model 27xx with an accessory card, verify 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 schematic diagram of the Model 7707 module. As shown, the Model 7707 has channels that are
grouped into two banks of five channels (10 channels total). Backplane isolation is provided for each bank. The first bank
contains channels 1 through 5 while the second bank contains channels 6 through 10. Each channel of the 10-channel
multiplexer card is wired with separate inputs for HI/LO providing fully isolated inputs.
NOTE Although the Model 7707 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.
Connections to DMM functions are provided through the card backplane connector for the following:
INPUT connections
SENSE ( Ω 4-wire) connections
Channel 15 (2W/4W configuration), Channel 16 (sense isolation), and Channel 17 (input isolation) are automatically
configured for normal system channel operation. When a 4-wire function is selected, the channels are paired as follows:
• CH1 and CH6
• CH2 and CH7
• CH3 and CH8
• CH4 and CH9
• CH5 and CH10
Dual independent multiplexers
Multiple channel operation ( ROUT:MULT:CLOS command) allows individual control of switching module channels. Multiple
channel operation allows the switching module to be configured as two independent multiplexers. The Model 7707 is normally
used as a single 1 × 10 multiplexer, but it can also be configured as two 1 × 5 multiplexers.
In Figure 1, the open position of channel 15 is shown. When channel 15 is closed, Multiplexer 1 (channels 1 through 5) is
isolated from Multiplexer 2 (channels 6 through 10).
For the dual multiplexer configuration, only channels 1 through 5 can be internally connected to the DMM of the Model 27xx.
Closing channel 17 allows channels 1 through 5 to be measured by the DMM.
When using the dual multiplexer configuration, channels 6 through 10 must be isolated from the sense terminals of the DMM
by keeping channel 16 open.

3
WARNING Multiple channel operation should only be performed by experienced test engineers who
recognize the dangers associated with multiple channel closures.
Digital I/O
As shown in Figure 1, channels 11, 12, 13, and 14 are digital I/O channels. Each digital I/O port can be configured as eight bits
of digital input or eight bits of digital output.
Figure 1
Simplified schematic for Model 7707
Note:
HI
LO
Sense
HI
LO
Input
To
27xx
DMM
Channel 17
(See Note)
Backplane
Isolat on
Channel 16
(See Note)
Backplane
Isolat on
B t
116
Channel 11
DIO
D g tal I/O
0
1
2
3
4
5
6
7
Channel 1 HI
LO
Channel 5
HI
LO
(Channels 24)
Channel 6
HI
LO
Channel 10
HI
LO
(Channels 79)
Channel 15
2-Pole / 4-Pole
(See Note)
Card Sense HI
LO
Card Input HI
LO
Channel 12
0
1
2
3
4
5
6
7
B t
1732
Channel 13
DIO
D g tal I/O
0
1
2
3
4
5
6
7
Channel 14
0
1
2
3
4
5
6
7
Channels 1517 n th s schemat c refer to the
des gnat ons used for control and not actual
ava lable channels.
These channels can be nd v dually controlled
us ng mult ple channel operat on(ROUT:MULT
commands). For more nformat on, refer to
Sect on 2 of the Model 27xx Users Manual.

4
Connections and wiring overview
WARNING All connection and wiring information is intended for qualified service personnel. Do
not make switching module connections unless qualified to do so.
To prevent electric shock that could result in serious injury or death, adhere to the
following safety precautions:
• Before removing or installing the switching module in the mainframe, make sure the
mainframe is turned off and disconnected from line power.
• Before making or breaking connections to the switching module, make sure power is removed
from all external circuitry.
• Do not connect signals that may exceed the maximum specifications of the Model 7707.
Specifications are provided at the end of this section.
D-shell connectors
Figure 2 shows the pin numbers for the Model 7707 rear panel connectors. The 50-pin D-shell is used to access digital input/
output channels, and the 25-pin D-shell is used to access analog input channels. Terminal identification for the D-shell
connector pins is provided in Table 1.
Figure 2
Rear view—Model 7707 pinouts
17
1
33
50
34
18
13 1
1425
50-pin D-shell connector (male) 25-pin D-shell connector (female)

5
Table 1
D-shell pin identification
50-pin D-shell (DB-50)
Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal
1 Gnd 11 Ch 13 Bit 3 21 Gnd 31 Ch 14 Bit 1 41 Protection K2
2 Ch 11 Bit 2 12 Ch 16 Bit 6 22 Ch 12 Bit 0 32 Ch 14 Bit 4 42 Gnd
3 Ch 11 Bit 5 13 Gnd 23 Ch 12 Bit 3 33 Ch 14 Bit 7 43 Ch 13 Bit 1
4 Protection K1 14 Gnd 24 Ch 12 Bit 6 34 Ch 11 Bit 0 44 Ch 13 Bit 4
5 Gnd 15 Ch 14 Bit 2 25 Gnd 35 Ch 11 Bit 3 45 Ch 13 Bit 7
6 Ch 12 Bit 1 16 Ch 14 Bit 5 26 Gnd 36 Ch 11 Bit 6 46 Gnd
7 Ch 12 Bit 4 17 Protection K4 27 Ch 13 Bit 2 37 Gnd 47 Ch 14 Bit 0
8 Ch 12 Bit 7 18 Ch 11 Bit 1 28 Ch 13 Bit 5 38 Gnd 48 Ch 14 Bit 3
9 Gnd 19 Ch 11 Bit 4 29 Protection K3 39 Ch 12 Bit 2 49 Ch 14 Bit 6
10 Ch 13 Bit 0 20 Ch 11 Bit 7 30 Gnd 40 Ch 12 Bit 5 50 Gnd
25-pin D-shell (DB-25)
Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal Pin
7707
Terminal
1 Ch 1 Hi 6 Ch 6 Hi 11 Sense Hi 16 Ch 3 Lo 21 Ch 8 Lo
2 Ch 2 Hi 7 Ch 7 Hi 12 Input Hi 17 Ch 4 Lo 22 Ch 9 Lo
3 Ch 3 Hi 8 Ch 8 Hi 13 — 18 Ch 5 Lo 23 Ch 10 Lo
4 Ch 4 Hi 9 Ch 9 Hi 14 Ch 1 Lo 19 Ch 6 Lo 24 Sense Lo
5 Ch 5 Hi 10 Ch 10 Hi 15 Ch 2 Lo 20 Ch 7 Lo 25 Input Lo

6
Wiring
NOTE The Model 7707 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 7707 is supplied with one 50-pin female 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 on the DB-25 (analog inputs), DO NOT
exceed 42V on any analog input in the test system (including the front panel inputs of
the Model 27xx). For higher voltage applications (up to 300V), use wire rated for the
application and add supplementary insulation to the wire harness ( Figure 6 ).
The DB-50 connector is used for digital I/O connections. DO NOT exceed 40V on any
digital terminal in the test system.
There are two connector kits that have connectors that can be used with the Model 7707:
• 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 female DB-50 and the male DB-25 mate to the D-shell connectors on the Model 7707.
• Model 7789 50/25-pin solder cup connector kit — Contains one male DB-50 and one male DB-25 solder cup
connectors. The male DB-25 mates to the 25-pin D-shell on the Model 7707.
IDC ribbon cable connections
WARNING When using IDC ribbon cable for analog inputs (DB-25), DO NOT exceed 42V on any
analog input (including front panel terminals). When using IDC ribbon cable for the
digital I/O (DB-50), DO NOT exceed 40V on any digital terminal.
Connect an appropriate length of 50-conductor IDC ribbon cable to a 50-pin female D-shell IDC connector, and connect an
appropriate length of 25-conductor IDC ribbon cable to a 25-pin male D-shell IDC connector. Table 2 and Figure 3 provide
terminal identification for the 50-pin ribbon cable connections. Table 3 and Figure 4 provide terminal identification for the
25-pin ribbon cable connections.
The connectors of the prepared ribbon cable assemblies mate to the 50- and 25-pin D-shell connectors of the Model 7707
(Figure 5). Make sure an unused D-shell connector has the connector cover installed.

7
Table 2
Terminal identification for 50-conductor IDC ribbon cable and 7707 DB-50 connector
Ribbon cable* 7707
Terminal
DB-50
Pin #
Ribbon cable* 7707
Terminal
DB-50
Pin #Conductor Color Conductor Color
1 Brown Gnd 1 26 Blue Gnd 42
2 Red Ch 11 Bit 0 34 27 Violet Gnd 26
3 Orange Ch 11 Bit 1 18 28 Grey Ch 13 Bit 0 10
4 Yellow Ch 11 Bit 2 2 29 White Ch 13 Bit 1 43
5 Green Ch 11 Bit 3 35 30 Black Ch 13 Bit 2 27
6 Blue Ch 11 Bit 4 19 31 Brown Ch 13 Bit 3 11
7 Violet Ch 11 Bit 5 3 32 Red Ch 13 Bit 4 44
8 Grey Ch 11 Bit 6 36 33 Orange Ch 13 Bit 5 28
9 White Ch 11 Bit 7 20 34 Yellow Ch 13 Bit 6 12
10 Black Protection K1 4 35 Green Ch 13 Bit 7 45
11 Brown Gnd 37 36 Blue Protection K3 29
12 Red Gnd 21 37 Violet Gnd 13
13 Orange Gnd 5 38 Grey Gnd 46
14 Yellow Gnd 38 39 White Gnd 30
15 Green Ch 12 Bit 0 22 40 Black Gnd 14
16 Blue Ch 12 Bit 1 6 41 Brown Ch 14 Bit 0 47
17 Violet Ch 12 Bit 2 39 42 Red Ch 14 Bit 1 31
18 Grey Ch 12 Bit 3 23 43 Orange Ch 14 Bit 2 15
19 White Ch 12 Bit 4 7 44 Yellow Ch 14 Bit 3 48
20 Black Ch 12 Bit 5 40 45 Green Ch 14 Bit 4 32
21 Brown Ch 12 Bit 6 24 46 Blue Ch 14 Bit 5 16
22 Red Ch 12 Bit 7 8 47 Violet Ch 14 Bit 6 49
23 Orange Protection K2 41 48 Grey Ch 14 Bit 7 33
24 Yellow Gnd 25 49 White Protection K4 17
25 Green Gnd 9 50 Black Gnd 50
* 50-conductor IDC ribbon cable is available from Keithley.

8
Figure 3
50-conductor ribbon cable terminal identification
26 Blue
27 Violet
28 Grey
29 White
30 Black
31 Brown 32 Red
33 Orange
34 Yellow
35 Green
36 Blue
37 Violet
38 Grey
39 White
40 Black
41 Brown
42 Red
43 Orange
44 Yellow
45 Green
46 Blue
47 Violet
48 Grey
49 White
50 Black
1 Brown
2 Red
3 Orange
4 Yellow
6 Blue
7 Violet
8 Grey
9 White
10 Black
11 Brown
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
5 Green
IDC Ribbon Cable 50-Conductor
50-pin D-shell
Female IDC
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Ground
Channel 11 Bit 0
Channel 11 Bit 1
Channel 11 Bit 2
Channel 11 Bit 3
Channel 11 Bit 4
Channel 11 Bit 5
Channel 11 Bit 6
Channel 11 Bit 7
Channel 12 Bit 0
Channel 12 Bit 1
Channel 12 Bit 2
Channel 12 Bit 3
Channel 12 Bit 4
Channel 12 Bit 5
Channel 12 Bit 6
Channel 12 Bit 7
Channel 13 Bit 0
Channel 13 Bit 1
Channel 13 Bit 2
Channel 13 Bit 3
Channel 13 Bit 4
Channel 13 Bit 5
Channel 13 Bit 6
Channel 13 Bit 7
Channel 14 Bit 0
Channel 14 Bit 1
Channel 14 Bit 2
Channel 14 Bit 3
Channel 14 Bit 4
Channel 14 Bit 5
Channel 14 Bit 6
Channel 15 Bit 7
Protection K1
Protection K2
Protection K3
Protection K4

9
Figure 4
25-conductor ribbon cable terminal identification
Table 3
Terminal identification for 25-conductor IDC ribbon cable and 7707 DB-25 connector
Ribbon cable* 7707
Terminal
DB-25
Pin #
Ribbon cable* 7707
Terminal
DB-25
Pin #Conductor Color Conductor Color
1 Brown Ch 1 Hi 1 14 Yellow Ch 7 Lo 20
2 Red Ch 1 Lo 14 15 Green Ch 8 Hi 8
3 Orange Ch 2 Hi 2 16 Blue Ch 8 Lo 21
4 Yellow Ch 2 Lo 15 17 Violet Ch 9 Hi 9
5 Green Ch 3 Hi 3 18 Grey Ch 9 Lo 22
6 Blue Ch 3 Lo 16 19 White Ch 10 Hi 10
7 Violet Ch 4 Hi 4 20 Black Ch 10 Lo 23
8 Grey Ch 4 Lo 17 21 Brown Sense Hi 11
9 White Ch 5 Hi 5 22 Red Sense Lo 24
10 Black Ch 5 Lo 18 23 Orange Input Hi 12
11 Brown Ch 6 Hi 6 24 Yellow Input Lo 25
12 Red Ch 6 Lo 19 25 Green — —
13 Orange Ch 7 Hi 7
* 25-conductor IDC ribbon cable is available from Keithley.
1 Brown HI Channel 1
LO
2 Red
3 Orange
4 Yellow
HI Channel 2
LO
HI Channel 3
LO
6 Blue
7 Violet
8 Grey
9 White HI Channel 5
LO
10 Black
11 Brown HI Channel 6
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 Channel 8
LO
5 Green
IDC Ribbon Cable —25-Conductor
HI Channel 4
LO
HI Channel 7
LO
HI Channel 9
LO
25-pin D-shell
Male IDC
HI Channel 10
LO
HI Sense
LO
HI Input
LO

10
Figure 5
Connecting ribbon cable assembly
Solder cup cable connections
Make all connections to D-shell male solder cup connectors 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. Terminal identification for the 25-pin D-shell connector is
provided in Table 1 and Table 3. Make sure to add supplementary insulation around the harness for voltages above 42V peak
(Figure 6).
WARNING For analog inputs (DB-25), all solder cup wiring must be rated for the maximum voltage
in the system. For example, if 300V is applied to the front terminals of the DMM, all
wiring for analog inputs must be rated for 300V.
For the digital I/O (DB-50), wiring must be rated for the maximum voltage applied to a
digital terminal (up to 40V).
A connector cover must be installed on an unused 50-pin D-shell connector. If the
connector is left open, an electrical shock hazard may be present.
Figure 6
Connecting solder cup cable assembly
WARNING: When using ribbon cable, on the DB-25, DO NOT
exceed 42 volts on any analog input in the test system
(including the front panel inputs of the Model 2700/2750).
The DB-50 connector is used for digital I/O connections.
DO NOT exceed 40V on any digital terminal in the test
system.
Install Plastic Cover
over unused connector
using two #4-40 screws.
KEITHLEY
CONNECTOR COVER
DB-50 DB-25
WARNING: When using a solder cup cable on the DB-25, use supplementary
insulation around the harness for voltages above 42V peak.
The DB-50 connector is used for digital I/O connections. DO NOT
exceed 40V on any digital terminal in the test system.
Install plastic cover
over unused connector
using two #4-40 screws.
KEITHLEY
CONNECTOR COVER
DB-50
Supplementary
Insulation
DB-25

11
Connection log
Make a copy of Table 4 and affix it to the cover of the Model 7707. Use this to record connection information and channel
descriptions as needed.
Table 4
Connection log Model 7707
Channel Color Description
INPUT H
L
SENSE H
L
CH1 H
L
CH2 H
L
CH3 H
L
CH4 H
L
CH5 H
L
CH6 H
L
CH7 H
L
CH8 H
L
CH9 H
L
CH10 H
L

12
Table 4 (cont)
Connection log Model 7707
Analog inputs
The following Model 7707 channels are used to measure analog input:
• Channels 1 through 10 are system measurement channels.
• Channel 15 is the 2-pole/4-pole selection relay.
• Channels 16 and 17 are the backplane isolation relays for sense and input respectively.
Operation
Operation to measure analog input is the same as operation for the Model 7700. The only exceptions are that the Model 7707
does not have any amps channels, and it does not have a cold junction for thermocouple temperature measurements.
Operation information for the Model 7700 switching module is provided in the Model 27xx User’s Manual. Section 2 covers
basic open/close operation, while the “Scanning” section covers scanning.
I/O
Line
Ch 11 Ch 12 Ch 13 Ch 14
In Out Color In Out Color In Out Color In Out Color
Bit 0 (B0) 0 1 (B8) 0 1 (B16) 0 1 (B24) 0 1
Bit 1 (B1) 0 1 (B9) 0 1 (B17) 0 1 (B25) 0 1
Bit 2 (B2) 0 1 (B10) 0 1 (B18) 0 1 (B26) 0 1
Bit 3 (B3) 0 1 (B11) 0 1 (B19) 0 1 (B27) 0 1
Bit 4 (B4) 0 1 (B12) 0 1 (B20) 0 1 (B28) 0 1
Bit 5 (B5) 0 1 (B13) 0 1 (B21) 0 1 (B29) 0 1
Bit 6 (B6) 0 1 (B14) 0 1 (B22) 0 1 (B30) 0 1
Bit 7 (B7) 0 1 (B15) 0 1 (B23) 0 1 (B31) 0 1
K1 K2 K3 K4
0 = low, 1 = high

13
Amps measurements
The 7707 module does not support amps measurements. System channel operation cannot be used to close channels while an
amps function (DCI or ICI) is selected.
If an amps function (DCI or ACI) is selected and you attempt to close a system channel, the message “NO AMPS CHAN” will
be displayed briefly. For remote programming, error -222 (Parameter data out of range) is generated. Example:
SYST:PRES ‘ Restores system preset defaults.
SENS:FUNC ‘CURR:DC’ ‘ Selects DCI function.
ROUT:CLOS (@101) ‘ Attempts to close system channel 101 – Generates error -222.
If a system channel is already closed and you attempt to select the DCI or ACI function, the message “INVALID FUNC” will
be displayed briefly. For remote programming, error -221 (Settings conflict) is generated. Example:
SYST:PRES ‘ Restores system preset defaults.
ROUT:CLOS (@101) ‘ Closes system channel 101.
SENS:FUNC ‘CURR:DC’ ‘ Attempts to select DCI function – Generates error -221.
Making amps measurements – In order to perform amps measurements, you must use the front panel inputs of the 27xx
mainframe. You can still use the 7707 module for other aspects of the test, but you must use multiple channel operation to close
channels. Example:
NOTE In order to use the front panel inputs, make sure the INPUT switch is in the out (F) position.
SYST:PRES ‘ Restores system preset defaults.
ROUT:MULT:CLOS (@101) ‘ Closes channel 101.
SENS:FUNC ‘CURR:DC’ ‘ Selects DCI function – Legal operation.
Dual independent multiplexers
Multiple channel operation can be used to configure the Model 7707 as two independent 1 × 5 multiplexers by closing
channel 15 (Figure 1). This isolates channels 1 through 5 from channels 6 through 10.
WARNING Multiple channel operation should only be performed by experienced test engineers who
recognize the dangers associated with multiple channel closures.

14
Typical analog input connections
The following examples show typical connections for the following types of measurements:
• Ω 2-Wire resistance and thermistor connections, Figure 7.
• Ω 4-Wire resistance and RTD connections, Figure 8.
• Voltage connections (AC or DC), Figure 9.
Figure 7
2-wire resistance and thermistor connections
Figure 8
4-wire resistance and RTD connections
Channel 1
HI
LO
Channel 10
HI
LO
(Channels 2–9) Resistors or
Thermistors
Channel 1
HI
LO
Channel 5
HI
LO
(Channels 2–4)
Channel 6
HI
LO
Channel 10
HI
LO
(Channels 7–9)
Resistor or
4-Wire RTD
Resistor or
4-Wire RTD

15
Figure 9
Voltage connections (AC or DC)
Digital I/O
The Model 7707 has four digital input/output channels (11, 12, 13, and 14). Each I/O channel can be set as either a digital
input port or a digital output port. As shown in Figure 10, each port has 8 lines (bits 0 through 7).
When an I/O channel is used as an input port, the state (high or low) of each input line (bit) can be read. When an I/O channel
is used as an output port, each line (bit) can be set high or low to control external circuitry.
Figure 10
Block diagram of digital I/O channels
Digital outputs
Digital outputs are used to control logic devices, indicators, fixtures, switches, solenoids, loads, relays, etc. With one I/O
channel set as an output port, eight output lines (bits) are available. With two channels set as output ports, 16 output lines (bits)
are available. With three channels set as output ports, 24 output lines (bits) are available. And finally, with all four channels set
as output ports, 32 output lines (bits) are available.
Channel 1
HI
LO
Channel 10
HI
LO
(Channels 2–9)
+
+
DC Voltage AC Voltage
Port 1
(In or Out)
Port 2
(In or Out)
Port 3
(In or Out)
Port 4
(In or Out)
Bit
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
1-16
Channel 11
Channel 12
Bit
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
17-32
Channel 13
Channel 14

16
An output line can be set high to ≈ 4.3V or low to 0V (digital ground). Output lines are set as follows:
• Logic ‘0’ sets output line low to 0V (digital ground).
• Logic ‘1’ sets output line high to ≈ 4.3V.
NOTE A digital I/O channel must first be configured as an output port before its output lines can be set
high or low. See Setting digital outputs on page 22, for details.
Sink or source
A digital output line (bit) can be used as a sink for an external source (up to 40V), or as a ≈4.3 V source for a low-current
device.
Sink mode
As a sink, current provided by an external source flows into the module when the output line is set low (logic ‘0’). Using an
output line as a sink provides control for high voltage (up to 40V) and/or high current (up to 100mA) devices, such as relays,
solenoids, and other loads. Figure 11, Figure 12, and Figure 13 show how to use an output line as a sink.
CAUTION Do not apply more than +40V to the K1, K2, K3, and K4 pins of the module. For the
output lines, do not exceed the maximum sink current. The maximum sink current for
an output line is 100mA. Exceeding these limits may cause damage to the instrument
that is not covered by the warranty.
Figure 11
Typical digital output—sink mode (with K1 protection)
Output
Control
(Ch 11 Bit 0)
Model 7707
Ch 11 Bit 0
Ground
User Supplied Circuitry
–
K1
Flyback
Diode
Zener
Clamp
K1 Protection Circuit
40V
External Source
Vmax = 40v
Imax = 100mA
Channel 11 set as
output port.
Relay
Flyback
Diode
–
External Source
≤40V
+
Equivalent Circuit
+
* Logic ‘1’
position shown.
Transistor
Switch*
Note: Setting output line low (logic ‘0’) closes
transistor switch to energize relay coil.

17
Figure 12
Typical digital output—sink mode (without K1 protection)
Figure 13
Typical digital output—sink mode (external flyback diode protection used)
Output
Control
(Ch 11 Bit 0)
Model 7707
Ch 11 Bit 0
Ground
User Supplied Circuitry
–
K1
Flyback
Diode
Zener
Clamp
K1 Protection Circuit
40V
External Source
Vmax = 40v
Imax = 100mA
Channel 11 set as
output port
+
Note: Setting output line low (logic ‘0’) closes transistor
switch to energize relay coil.
Model 7707
User Supplied Circuitry
–
Ch 11 Bit 0
Ground
Channel 11 set
as output port
Output
Control
(Ch 11 Bit 0)
Flyback
Diode
+External Source
Vmax = 40V
Imax = 100mA
Note: Setting output line low (logic ‘0’) closes
transistor switch to energize relay coil.