Keithley S46 User manual

www.keithley.com
A GREATER MEASURE OF CONFIDENCE
S46/S46T/S46L Microwave Switch System
Instruction Manual
S46-901-01 Rev. F / March 2011

S46/S46T/S46L Microwave Switch System
Instruction Manual
©2001-2011, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Document number: S46-901-01 Rev. F / March 2011
All Keithley Instruments product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders

Safety Precautions
11/07
The following safety precautions should be observed before using this product and any associated instrumentation. Although some
instruments and accessories would normally be used with nonhazardous voltages, there are situations where hazardous conditions may
be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required
to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before using the product. Refer
to the user documentation for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product warranty 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 ensuring 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 instrument.
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 described in the user documentation. 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, perform safe installations, and repair products. Only properly trained service
personnel may perform installation and service procedures.
Keithley Instruments 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 signals are Measurement Category I and must not be directly connected 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/Oconnections are for connection to Category I sources unless otherwise
marked or described in the user documentation.
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 30 V RMS, 42.4 V peak,
or 60 V DC 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
prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact.
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 V, 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 connecting sources to switching cards, install protective devices to limit fault current
and voltage to the card.
Before operating an instrument, ensure that the line cord is connected 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
disconnect device must be provided in close proximity to the equipment 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 jumpers,
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 common 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
equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information,
and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with the 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 applied to the device under test. Safe operation requires the use of a lid
interlock.
If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.
The symbol on an instrument means caution, risk of danger. The user should refer to the operating instructions located in the user
documentation in all cases where the symbol is marked on the instrument.
The symbol on an instrument means caution, risk of electric shock. Use standard safety precautions to avoid personal contact with
these voltages.
The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.
The symbol indicates a connection terminal to the equipment frame.
If this symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be properly
disposed of according to federal, state, and local laws.
The WARNING heading in the user documentation explains dangers that might result in personal injury or death. Always read the
associated information very carefully before performing the indicated procedure.
The CAUTION heading in the user documentation 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 Instruments. 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 selected parts should be purchased only through Keithley Instruments to maintain
accuracy and functionality of theproduct). If you are unsure aboutthe applicability ofa replacement component, calla KeithleyInstruments
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., a data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the
board becomes contaminated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.
!

Section Topic Page
1General Information ....................................................................... 1-1
Introduction................................................................................................. 1-1
Feature overview........................................................................................ 1-1
Manual addenda......................................................................................... 1-2
Specifications.............................................................................................. 1-2
Unpacking and inspection........................................................................... 1-2
Inspection for damage.......................................................................... 1-2
Shipment contents ............................................................................... 1-2
Repacking for shipment ....................................................................... 1-2
Available accessories................................................................................. 1-2
SMA cables and torque wrench ........................................................... 1-3
Relay kits.............................................................................................. 1-3
Replacement relays ............................................................................. 1-4
Connections................................................................................................ 1-4
Installation................................................................................................... 1-5
Rack mounting..................................................................................... 1-5
Foot mounting...................................................................................... 1-6
2Connections.................................................................................... 2-1
Introduction................................................................................................. 2-1
Handling precautions.................................................................................. 2-1
System configuration.................................................................................. 2-1
Layout .................................................................................................. 2-1
Simplified schematic ............................................................................ 2-3
Connections................................................................................................ 2-4
Signal connections............................................................................... 2-6
GPIB control connection ...................................................................... 2-6
Power connections............................................................................... 2-8
Ground connection............................................................................. 2-11
Switching considerations.......................................................................... 2-11
Connector integrity............................................................................. 2-11
Voltage standing wave ratio ............................................................... 2-12
Path isolation...................................................................................... 2-12
Insertion loss...................................................................................... 2-12
RFI/EMI.............................................................................................. 2-12
3Operation ........................................................................................ 3-1
Introduction................................................................................................. 3-1
Signal considerations ................................................................................. 3-1
Bus operation (GPIB) ................................................................................. 3-1
Bus connections................................................................................... 3-2
Primary address................................................................................... 3-2
Programming syntax............................................................................ 3-2
Response messages............................................................................ 3-5
GPIB commands ........................................................................................ 3-6
ROUTe commands............................................................................... 3-6
STATus commands .............................................................................. 3-9
SYSTem commands........................................................................... 3-11
Status model............................................................................................. 3-12
Table of Contents

Table of Contents S46/S46T/S46L Microwave Switch System Instruction Manual
ii Document number: S46-901-01 Rev. F / March 2011
Event register sets.............................................................................. 3-13
Enable registers.................................................................................. 3-14
Queues............................................................................................... 3-14
Status byte and SRQ.......................................................................... 3-16
Service Request Enable Register....................................................... 3-18
Serial polling and SRQ ....................................................................... 3-18
Clearing registers and queues .................................................................. 3-18
Programming enable registers.................................................................. 3-19
Reading registers................................................................................ 3-20
Common commands................................................................................. 3-20
Errors ........................................................................................................ 3-26
4Service Information ........................................................................4-1
Introduction ................................................................................................. 4-1
Handling and cleaning precautions..............................................................4-1
Handling precautions............................................................................ 4-1
Circuit board and connector cleaning ....................................................4-1
Coaxial switch performance verification...................................................... 4-2
Environmental conditions...................................................................... 4-2
Recommended equipment.................................................................... 4-2
Channel resistance tests ...................................................................... 4-2
RF performance verification.................................................................. 4-3
Replacing components.................................................................................4-4
Replacing relays................................................................................... 4-4
Mainframe replacement parts............................................................... 4-6
Replacement precautions..................................................................... 4-6
Soldering considerations ...................................................................... 4-6
Disassembly ..........................................................................................4-6
Ordering information ....................................................................................4-9
Factory service............................................................................................ 4-9
Index .................................................................................................. Index-1

Section 1
General Information
Introduction
This section contains general information about the S46/S46T/S46L Microwave Switch System.
The information is organized as follows:
•Feature overview
•Manual addenda
•Unpacking and inspection
•Available accessories
•Connections
•Installation
WARNING If the equipment is not used as recommended by the manufacturer,
the overall safety will be impaired.
If you have any questions after reviewing this information, please contact your local Keithley
Instruments representative or call Keithley Instruments corporate headquarters (toll-free inside the
U.S. and Canada only) at 1-888-KEITHLEY (1-888-534-8453), or from outside the U.S. at
[phone]. For worldwide contact numbers, visit the Keithley Instruments website at
www.keithley.com.
Feature overview
The System 46 (S46) is an IEEE-488 bus controlled 19-inch rack-mounted RF relay switch
controller instrument. The standard S46 configurations can accommodate eight SPDT
unterminated coaxial microwave relays and four multi-pole, unterminated, coaxial microwave
relays. Any of these multi-pole unterminated relays can be one of the following relay types: SP4T
or SP6T.
S46 switching systems can be used as multiplexers, matrices, independent relays, or a
combination of configurations. Additional features of the S46 are as follows:
• Can be populated with up to eight 2-pole RF relays and a maximum of four, 4-pole, or 6-pole
RF relays
• LED indicators for error, power, and relay status
• Operating range to 40 GHz (relay dependent)
The System 46T (S46T) is also an IEEE-488 bus controlled 19-inch rack-mounted RF relay switch
controller instrument. In addition to the unterminated configurations that the S46 provides, the
S46T also has provisions to accommodate four terminated multi-pole, coaxial microwave relays,
or up to four transfer switches (DPDT) as well, with frequency ranges up to 26.5 GHz.
The System 46L (S46L) is also an IEEE-488 bus controlled 19-inch rack-mounted RF relay switch
controller instrument. The S46L only supports terminated relays in order to achieve 10 m cycle
closures. It can support up to four SP6T and four SPDT terminated relays.

1-2 Document number: S46-901-01 Rev. F / March 2011
Section 1: General Information S46/S46T/S46L Microwave Switch System Instruction Manual
Manual addenda
Any improvements or changes concerning the S46/S46T/S46L Microwave Switch System will be
explained in an addendum included with the user documentation. Be sure to note these changes
and incorporate them into the documentation.
Specifications
Check the Keithley Instruments website (www.keithley.com/support) for latest version of the
product specifications.
Unpacking and inspection
Inspection for damage
The S46/S46T/S46L was carefully inspected electrically and mechanically before shipment. After
unpacking all items from the shipping carton, check for any obvious signs of physical damage that
may have occurred during transit. Report any damage to the shipping agent immediately. Save the
original packing carton for possible future shipment.
Shipment contents
The following items are included with every S46/S46T/S46L order:
• S46/S46T/S46L Microwave Switch System (includes power cord)
• Product Information CD-ROM (part number S46-950-01), which includes the S46/S46T/
S46L Microwave Switch System Instruction Manual (part number S46H-901-01) and other
product-related information
• Installation instructions (part number PA-778, PA-910, PA-913, or PA-1031) for the relay kits
(see Relay kits)
• Additional accessories as ordered
Repacking for shipment
Should it become necessary to return the S46/S46T/S46L for repair, carefully pack the instrument
in its original packing carton or the equivalent, and follow these instructions:
• Call the Repair Department at 1-800-552-1115 for a Return Material Authorization (RMA)
number.
• Advise as to the warranty status of the S46/S46T/S46L.
• Write ATTENTION REPAIR DEPARTMENT and the RMA number on the shipping label.
Available accessories
NOTE Check the Keithley Instruments website (www.keithley.com) for additional
accessories that may have been added to the Keithley product line for the S46/
S46T/S46L.

Document number: S46-901-01 Rev. F / March 2011 1-3
S46/S46T/S46L Microwave Switch System Instruction Manual Section 1: General Information
SMA cables and torque wrench
•S46-SMA-0.5: DC-18 GHz, low loss, semi-flex SMA-to-SMA cable assembly, 0.152 m
(6 in.) in length
•S46-SMA-1: DC-18 GHz, low loss, semi-flex SMA-to-SMA cable assembly, 0.305 m (12 in.)
in length
•S46-SMA-1.7: DC-18 GHz, low loss, semi-flex SMA-SMA cable assembly, 0.518 m
(20.4 in.)
•S46-SMA26-0.5: DC-26.5 GHz, low loss, semi-flex SMA-SMA cable assembly, 0.152 m
(6 in.)
•S46-SMA26-1: DC-26.5 GHz, low loss, semi-flex SMA-SMA cable assembly, 0.305 m
(12 in.)
•S46-SMA26-1.7: DC-26.5 GHz, low loss, semi-flex SMA-SMA cable assembly, 0.518 m
(20.4 in.)
•S46-TW: SMA cable torque wrench
Relay kits
Relays can be added to your test system by ordering relay kits from Keithley. Each kit includes a
relay, a cable assembly, any necessary hardware, and installation instructions. The installation
instructions are are also provided on the CD-ROM that is supplied with the S46/S46T/S46L.
S46 switch kits
•S46-SPDT-KIT: Standard-performance 18 GHz unterminated SPDT relay and control cable
assembly
•S46-SP4T-KIT: Standard-performance 18 GHz unterminated SP4T relay and control cable
assembly
•S46-SP6T-KIT: Standard-performance 18 GHz unterminated SP6T relay and control cable
assembly
•S46-SPDT-KIT-R: High-performance 18 GHz unterminated SPDT relay and control cable
assembly
•S46-SP4T-KIT-R: High-performance 18 GHz unterminated SP4T relay and control cable
assembly
•S46-SP6T-KIT-R: High-performance 18 GHz unterminated SP6T relay and control cable
assembly
•S46-SPDT-KIT-26: High-performance 26.5 GHz unterminated SPDT relay and control cable
assembly
•S46-SP4T-KIT-26: High-performance 26.5 GHz unterminated SP4T relay and control cable
assembly
•S46-SP6T-KIT-26: High-performance 26.5 GHz unterminated SP6T relay and control cable
assembly
•S46-SPDT-KIT-40: High-performance 40 GHz unterminated SPDT relay and control cable
assembly
•S46-SP4T-KIT-40: High-performance 40 GHz unterminated SP4T relay and control cable
assembly
•S46-SP6T-KIT-40: High-performance 40 GHz unterminated SP6T relay and control cable
assembly
S46T switch kits
•S46T-SPDT-KIT-26: High-performance 26.5 GHz unterminated SPDT relay, spacer block,
and control cable assembly

1-4 Document number: S46-901-01 Rev. F / March 2011
Section 1: General Information S46/S46T/S46L Microwave Switch System Instruction Manual
•S46T-SPDT-KIT-26T: High-performance 26.5 GHz terminated SPDT relay and control cable
assembly
•S46T-SP4T-KIT-26: High-performance 26.5 GHz unterminated SP4T relay, mounting plate,
and control cable assembly
•S46T-SP4T-KIT-26T: High-performance 26.5 GHz terminated SP4T relay and control cable
assembly
•S46T-SP6T-KIT-26: High-performance 26.5 GHz unterminated SP6T relay, mounting plate,
and control cable assembly,
•S46T-SP6T-KIT-26T: High-performance 26.5 GHz terminated SP6T relay and control cable
assembly
•S46T-SPDT-KIT: 18 GHz unterminated SPDT relay, spacer block, and control cable
assembly
•S46T-SPDT-KIT-T: 18 GHz terminated SPDT relay and control cable assembly
•S46T-MSPDT-KIT: Quantity 2, 18 GHz unterminated SPDT relays, mounting plate, and
control cable assembly (Note: Kit applicable only for relay A-D mounting locations)
•S46T-MSPDT-KIT-26: Quantity 2, 26 GHz unterminated SPDT relays, mounting plate, and
control cable assembly (Note: Kit applicable only for relay A-D mounting locations)
•S46T-SP4T-KIT: 18 GHz unterminated SP4T relay, mounting plate, and control cable
assembly
•S46T-SP4T-KIT-T: 18 GHz terminated SP4T relay and control cable assembly
•S46T-SP6T-KIT: 18 GHz unterminated SP6T relay, mounting plate, and control cable
assembly
•S46T-SP6T-KIT-T: 18 GHz terminated SP6T relay and control cable assembly
•S46T-XFER-KIT: 18 GHz transfer switch, mounting plate, and control cable assembly
•S46T-XFER-KIT-26: 26.5 GHz transfer switch, mounting plate, and control cable assembly
S46L switch kits
•S46L-SPDT-KIT-L: High-performance 20 GHz terminated SPDT relay, spacer block, and
control cable assembly
•S46L-SP6T-KIT-T: High-performance 18 GHz terminated SP6T relay and control cable
assembly
Replacement relays
NOTE The procedures for Replacing relays are provided in Section 4.
Defective relays can be replaced by ordering the appropriate relay kit.
Connections
Available S46/S46T/S46L connections include:
• Female SMA coaxial connectors for all front-panel input and output connections
• Power receptacle: Standard three-prong AC line connector on rear panel
• GPIB port (IEEE-488 connector) on rear panel

Document number: S46-901-01 Rev. F / March 2011 1-5
S46/S46T/S46L Microwave Switch System Instruction Manual Section 1: General Information
NOTE Refer to Section 2 for detailed connection information.
Installation
You can either mount the S46/S46T/S46L in a rack using the supplied rack-mounting hardware, or
operate it on a bench by installing the supplied feet, as described in Foot mounting.
Rack mounting
The S46/S46T/S46L can be mounted in a standard 19-inch rack. The hardware necessary to
install the instrument in a rack is supplied with the S46/S46T/S46L.
Rack-mount kit
The S46/S46T/S46L is supplied with a Model 4288-7 rack-mount kit, which mounts the instrument
in a standard 19-inch rack. This kit includes rear brackets to provide additional support for the
instrument.
Rack-mount procedure
WARNING Make sure the S46/S46T/S46L is turned off, the line cord is
disconnected, and it is not connected to any external circuitry.
The power supply cord must be used as the mains disconnecting
device. The plug should be located in close proximity to the user
and remain readily accessible at all times.
To install the S46/S46T/S46L in the rack:
1. Select a location in the rack. The instrument fills 3.5 inches of vertical space.
2. Using Figure 1-1 as a guide, install two retaining clips on the left front rail. Slide each
retaining clip over a mounting hole so that the captive nut is positioned on the inside of the
rack cabinet. Install two retaining clips on the right front rail using the same procedure.
Figure 1-1
Rack preparation
3. If installed, remove the four feet from the bottom of the S46/S46T/S46L. Retain these feet
for future use.
4. Position the S46/S46T/S46L in the rack, and loosely attach the front panel to the rack rails
using the four supplied dress screws.
1.75”
Left Front
Rack Rail
Retaining
Clips with
Nuts

1-6 Document number: S46-901-01 Rev. F / March 2011
Section 1: General Information S46/S46T/S46L Microwave Switch System Instruction Manual
5. Tighten the four dress screws.
6. Install and secure the rear brackets as described in the instructions supplied with the
rack-mount kit.
CAUTION Installation of the rear brackets is recommended to properly support the
S46/S46T/S46L.
Foot mounting
To operate the S46/S46T/S46L on a bench, attach the supplied rubber feet to the bottom of the
instrument. Each foot can be attached by removing the adhesive covering, and then pressing the
foot into place in a suitable location near each corner on the bottom case cover. These feet should
be removed before rack-mounting the instrument (see Rack mounting).

Section 2
Connections
Introduction
This section contains information about overall switch system configuration and connections and
is organized as follows:
• Handling precautions
• System configuration
• Connections
• Switching considerations
WARNING The procedures in this section are intended only for qualified
service personnel. Do not perform these procedures unless you
are qualified to do so. Failure to recognize and observe normal
safety precautions could result in personal injury or death.
Handling precautions
To maintain high-impedance isolation, be careful when handling the S46/S46T/S46L to avoid
contamination from foreign materials such as body oils. Such contamination can reduce isolation
resistance. To avoid possible contamination:
• Do not touch connector insulators.
• Operate the switch controller in a clean environment. If the instrument becomes
contaminated, it should be thoroughly cleaned as explained in Circuit board and connector
cleaning in Section 4.
System configuration
Layout
The S46, S46T, and S46L front panels are separately illustrated in Figure 2-1, and Figure 2-2
shows the rear panel for all three models.
All systems feature:
Connectors:
• Relay input and output connectors (see front panel)
• Power line receptacle (see rear panel)
• GPIB Control: IEEE-488 interface connector (see rear panel)

2-2 Document number: S46-901-01 Rev. F / March 2011
Section 2: Connections S46/S46T/S46L Microwave Switch System Instruction Manual
Indicators (see front panel):
• Relay state LEDs (one for each relay)
• Power LED
• ERR LED (communication error or failed power on self-test)
Figure 2-1
S46/S46T/S46L front panels
Status LEDs
2-pole relay
connections
StatusLEDs
4-pole, 6-pole, XFER, or MSPDT
relay connections
2-pole relay
connections
SP4T
SP3T
SP5T SP6T
S46 MICROWAVE SWITCH SYSTEM
PWR 1 3 5 1 3 5 1 3 5 1 3 5 R1 R3 R5 R7
ERR2 4 6 24 62 46 24 6R2R4R6R8
RA RB RC RD
RELAY 1 RELAY 2 RELAY 3 RELAY 4
NO C NC NO C NC NO C NC NO C NC
RELAY 5 RELAY 6 RELAY 7 RELAY 8
NO C NC NO C NC NO C NC NO C NC
RELAY A RELAY B RELAY C RELAY D
4-pole or 6-pole relay connections
System 46T
System 46
NO C NC
NO C NC
NO C NC
NO C NC
NO C NC
NO C NC
NO C NC
NO C NC
NO C NCNO C NCNO C NCNO C NC NO C NC NO C NC NO C NC NO C NC
Status LEDs
2-pole relay
connections
4-pole or 6-pole relay connections
System 46L

Document number: S46-901-01 Rev. F / March 2011 2-3
S46/S46T/S46L Microwave Switch System Instruction Manual Section 2: Connections
Figure 2-2
Rear panel (all models)
Simplified schematic
Figure 2-3 shows a simplified schematic diagram of the S46/S46T/S46L. Configuration is as
follows:
• RELAY 1 through RELAY 8 (for S46L, RELAY 1 through RELAY 4) are 2-pole relays, each
with two inputs (normally closed and normally open) and one common.
• RELAY A through RELAY D on the S46 and S46T can be 4-pole, 6-pole, or MSPDT relays,
each with a maximum of six inputs and one common. The number of inputs depends on
relay configuration, as shown by the dotted lines in the diagram. The S46T can also
accommodate up to four transfer switches. The S46L only supports SP6T relays.
1 42 816
Primary Address
DIP Switch IEEE-488
Connector
!
!42V MAX.
ANY CONDUCTOR
CAUTION:
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE FUSE WITH SAME TYPE AND RATING.
Line Fuse
Power Line
Receptac e
LINE FUSE
SLOWBLOW
1.6A, 25 V
LINE RATING
1 -24 VAC
5 , 6 Hz
8 VA MAX

2-4 Document number: S46-901-01 Rev. F / March 2011
Section 2: Connections S46/S46T/S46L Microwave Switch System Instruction Manual
Figure 2-3
Simplified schematic
Connections
Signal connections
RF input and output connections are made either to the RELAY 1 through RELAY 8 connectors, or
to the RELAY A through RELAY D connectors, as described below.
Unterminated SP4T, SP6T, XFER (26.5 GHz), and unterminated 40 GHz relays have female SMA
2.9 connectors. All others have female SMA connectors.
RELAY A to RELAY D
4-po e or 6-po e
RELAY 1 to RELAY 8
2-po e
Norma y
C osed
Norma y
Open Common
Connection
RELAY A to RELAY D
MSPDT switch
RELAY A to RELAY D
XFER switch
Norma y
C osed
Norma y
Open Common
Connection
Norma y
C osed
Norma y
Open Common
Connection
Top
Re ay
Bottom
Re ay
Input
Connections
2
3
4
5
6
1
Common
Connection
Input
Connections
2
1
()
(+)
Power
Termina s
Actuator
3
4
De-energized
Position
Energized
De-energized
RF Switching 13, 24
12, 34

Document number: S46-901-01 Rev. F / March 2011 2-5
S46/S46T/S46L Microwave Switch System Instruction Manual Section 2: Connections
Cables
Only use 50 Ωcables specified for operation at the system frequency (18 GHz, 26.5 GHz, or
40 GHz).
Relay configuration
The S46/S46T/S46L can be populated with relays as follows:
• RELAY A, B, C, and D can be populated with either 4-pole or 6-pole relays. The S46T can
also accommodate up to four transfer switches (DPDT), MSPDT, and unterminated SP4T
and SP6T relays. Make sure that you note the operational differences in these relays (see
Section 3). The S46L only supports SP6T relays.
• RELAY 1 through RELAY 8 (RELAY 1 through RELAY 4 for S46L) are populated with 2-pole
RF relays.
• Any or all relay locations can be populated.
Channel assignments
Table 2-1 summarizes relay channel assignments. See Section 3 for information about controlling
channels.
NOTE Regardless of the pole configuration of RELAY A, RELAY B starts numbering at
channel 7.
Input/output connections
Figure 2-4 shows input and output connections for both RELAY A through RELAY D and RELAY 1
through RELAY 8. RELAY A through RELAY B have up to six input connections and one output
connection (depending on relay pole configuration). RELAY 1 through RELAY 8 each have two
input connections and one output connection.
Table 2-1
Relay channel assignments
Relay Channels
RELAY A 1 through 6
RELAY B 7 through 12
RELAY C 13 through 18
RELAY D 19 through 24
RELAY 1 to 8 25 through 32

2-6 Document number: S46-901-01 Rev. F / March 2011
Section 2: Connections S46/S46T/S46L Microwave Switch System Instruction Manual
Figure 2-4
Relay input and output connections
Transfer switch (XFER)
Up to four transfer switches (DPDT) can be located in Relay positions A through D. The transfer
switch cross-connects two input ports with two output ports. When using transfer switches, make
sure that you note the operational differences of these switches (see Section 3).
GPIB control connection
The rear-panel, IEEE-488 (GPIB) control port is connected to the GPIB port of a computer
(controller) using a shielded IEEE-488 interface cable with metric mating screws. Figure 2-5 shows
the GPIB control connector, and Table 2-2 summarizes the GPIB control connector terminals.
RELAY 1 to 8 Connections RELAY A to D Connections
C = Common
1 to 4 = Inputs
C
2
6
53
4-po e
Terminated
1 to 4 = Inputs
1
3
2
4
XFER
Un-terminated
C = Common
1 to 6 = Inputs
6-po e
C
1
4
2
3
6
5
C = Common
1 to 4 = Inputs
C
1
4
32
4-po e MSPDT
C = Common
1 to 6 = Inputs
6-po e
C
1
4
2
3
6
5
Terminated
Un-terminated
NCNO C
NCNO C
NCNO C
NC = Norma y C osed
NO = Norma y Open
C = Common

Document number: S46-901-01 Rev. F / March 2011 2-7
S46/S46T/S46L Microwave Switch System Instruction Manual Section 2: Connections
Figure 2-5
GPIB control connector
Remember the following restrictions when attaching instruments to the GPIB:
• A maximum separation of 4 meters between any two instruments on the bus
• A maximum total cable length of 20 meters
• No more than 15 devices on the bus
• No two instruments can have the same address
If you cannot meet these requirements, the use of bus extenders is recommended.
CAUTION IEEE-488 common is connected to digital common. Maximum voltage
between digital common and earth ground is 0 V.
Connectors may be stacked to allow a number of parallel connections to one instrument. Two
screws located on a standard connector maintain secure connections between connectors.
NOTE To minimize interference caused by electromagnetic radiation, use shielded
IEEE-488 cables such as the Keithley Model 7007.
To connect devices to the GPIB:
1. Line up the cable connector with the IEEE-488 connector located on the rear panel of the
S46/S46T/S46L. The connector’s design allows installation to the port in only one position.
2. Secure the connector by tightening the screws firmly (do not overtighten).
3. Add any additional connectors to the port, as required.
4. Connect the free end of the cable to the controller.
5. Confirm that the primary address is set properly (see Section 3 for GPIB address
information).
1
12
13
24

2-8 Document number: S46-901-01 Rev. F / March 2011
Section 2: Connections S46/S46T/S46L Microwave Switch System Instruction Manual
GPIB primary address
On the rear panel, there are five GPIB DIP switches to set the GPIB primary address. The GPIB
address is set to 7 at the factory. Refer to Section 3 of this manual for information about setting the
primary address.
Power connections
Line voltage
The S46/S46T/S46L operates from a line voltage in the range of 100 V to 240 V at a frequency of
50 Hz or 60 Hz. Line voltage selection is automatic.
CAUTION Operating the S46/S46T/S46L on an incorrect line voltage may cause
damage, possibly voiding the warranty.
Table 2-2
GPIB control connector terminals
Contact number IEEE-488 designation Type
1DI01 Data
2DI02 Data
3DI03 Data
4DI04 Data
5 EOI (24)* Management
6 DAV Handshake
7 NRFD Handshake
8 NDAC Handshake
9 IFC Management
10 SRQ Management
11 ATN Management
12 SHIELD Ground
13 DI05 Data
14 DI06 Data
15 DI07 Data
16 DI08 Data
17 REN (24)* Management
18 Gnd (6)* Ground
19 Gnd (7)* Ground
20 Gnd (8)* Ground
21 Gnd 9)* Ground
22 Gnd (10)* Ground
23 Gnd (11)* Ground
24 Gnd, LOGIC Ground
* Numbers in parentheses refer to signal ground return of referenced
contact number. EOI and REN signal lines return on contact 24.