Agilent L4421A
40-Channel Armature Multiplexer
Data Sheet
• LXI compliance includes
built-in Ethernet connectivity
• Fully-featured graphical
Web interface
• 40 2-wire latching
armature relays
• Thermocouple reference
junction for temperature
measurements
(reqs ext DMM)
• Relay counter
• Scan up to 100 ch/s
• 300 V, 1 A switch;
2 A carry current
• Software drivers for
most common programming
environments
40-channel multiplexer offers
high-performance signal
switching wherever your
application needs it
The Agilent L4421A is a
high-performance 40-channel
armature multiplexer that is
LXI Class C compliant. With
its small size and Ethernet
connectivity, this switch can
be placed wherever your
application needs it.
The L4421A is a versatile multi-
plexer for general purpose
scanning. The low thermal
offset characteristics and
built-in thermocouple reference
on the terminal block, make
it ideal for temperature mea-
surements with an external
DMM. The dense, multi-function
switching with 100 channel/
second scan rates addresses
a broad spectrum of data acqui-
sition, design verification and
functional test applications.
The Ethernet connection also
simplifies distributed data
acquisition so that you can
collect data from multiple
locations.
Four additional fused inputs
(44 channels total) can route up
to 1 A of current to an external
DMM, allowing for AC and DC
current measurements without
the need for external shunt
resistors.
Using this LXI instrument, you’ll
get all the benefits of an Ethernet
connection, instrument web
server, standard software drivers
and more. The LXI standard is
supported by multiple vendors,
enabling lower cost of test with
accelerated test integration and
development.
Switch features for flexible
and reliable connections
Connect one of many different
points to a single point or create
your own custom configuration
with multiple connections. When
configured as a multiplexer, the
L4421A features break-before-
make connections to ensure that
no two signals are connected
to each other during a scan.
The sequence feature defines
switch sequences and controls
complex signal routing to ensure
the order of switch closures.
Assign a sequence, give it a
name and then execute it with
the custom name you created.
External trigger capabilities
make it easy for you to time
and synchronize measurements
and other events. This can help
you determine when to begin
or end an acquisition.
The L4421A also includes a
relay counter to monitor and
help predict when relays are
nearing their end of life.
Easily route signals
to an external DMM
The L4421A switches support
signals up to 300 V and 1 A so
that no external signal condi-
tioning is required. The 34921T
features a built-in thermocouple
reference that allows for scanning
temperature measurements with
an external DMM. The analog
bus connector can be used to
easily route your multiplexed
signals to an external DMM.
Hardware handshake with an
external DMM is supported
through a Channel closed trigger
output and a Channel advance
trigger input.
System connections you can trust
The L4421A comes with 2 heavy
duty 50-pin Dsub connectors
that allow for simple, reliable
connection options. Each con-
nector uses 30 micro-inches
of gold to ensure a repeatable,
accurate measurement.
Flexible connection options
include:
• Detachable terminal blocks
with strain relief
• Low-cost, standard
50-pin Dsub connector
kits and cables
• Mass interconnect solutions
Ethernet connectivity enables
simple connection to the
network and remote access
to measurements
The Ethernet interface offers
high-speed connections that
allow for remote access and
control. You can set up a
private network to filter out
unwanted LAN traffic and
speed up the I/O throughput,
or take advantage of the remote
capabilities and distribute
your tests worldwide. Monitor,
troubleshoot, or debug your
2
Figure 1. L4421A 40-channel armature multiplexer with low thermal offset (bank 2)
application remotely. Ethernet
communication also can be
used with the support of
LAN sockets connections.
The optional GPIB interface
has many years of proven
reliability and can be used for
easy integration into existing
applications.
The L4421A ships with the
Agilent E2094N I/O Libraries
Suite making it easy for you to
configure and integrate instru-
ments into your system — even
if your system includes instru-
ments from multiple vendors.
Fully-featured graphical web
interface makes it easy to set-up
and troubleshoot your tests from
anywhere in the world
The built-in Web browser inter-
face provides remote access
and control of the instrument
via a Java-enabled browser
such as Internet Explorer.
Using the Web interface, you
can set up, troubleshoot, and
maintain your instrument
from remote locations.
• View and modify
instrument setup
• Open or close switches
• Send, receive and view
SCPI commands
• Define and execute
switch sequences
• View error queue
• Get status reports on
relay counts, firmware
revisions, and more
Additionally, since the Web
server is built into the instru-
ment, you can access it on any
operating system that supports
the Web browser without having
to install any special software.
Password protection and LAN
lockout are also provided to
limit access for additional
security.
Software for most popular
programming environments
Full support for standard
programming environments
ensures compatibility and
efficiency. You can use direct
I/O with the software you
already have and know, or
use standard IVI and LabVIEWTM
software drivers that provide
compatibility with the most
popular development
environments:
• Agilent T&M Toolkit for
Microsoft Visual Studio®.NET
and Agilent VEE Pro
• National Instruments
LabVIEW, LabWindows/CVI,
TestStand, and Switch
Manager
• Microsoft C/C++® and
Visual Basic®
3
Figure 2. The Web interface makes it easy to set up, troubleshoot and maintain
your test remotely
4
High-performance switching wherever your application needs it
Power button
Status LEDs
External trigger to
synchronize events
Optional GPIB Built-in Ethernet
Analog bus for
connection to
other devices
Easy connection options
with terminal blocks,
standard 50-pin
cables or connector kits
5
Specifications and Characteristics
Channels/configurations 40 2-wire
20 4-wire
4-current (1.5 A fused)
Switch type Armature Latching
Input characteristics (per channel)
Max volts (DC, AC RMS)1±300 V
Max current (DC, AC RMS)
Switch current 1 A
Carry current 2 A
Power (W, VA)460 W
Volt-Hertz limit 108
General specifications
Offset voltage2<3 uV
Initial closed channel resistance2< 1.5 Ω
DC Isolation (ch-ch, ch-earth) >10 GΩ
T/C cold junction accuracy2,6 < 0.8 °C
AC characteristics
Bandwidth at terminal block345 MHz
Crosstalk at terminal block (ch-ch)3
300 kHz -75 dB
1 MHz -75 dB
20 MHz -50 dB
45 MHz -40 dB
Capacitance at terminal block
HI-LO 150 pF
LO – earth 150 pF
General characteristics
Relay life typical
No load 100 M
10 V, 100 mA 10 M
Rated load = 100 k
Scanning speeds5100 ch/s
Open /close time, typical 4 ms/4 ms
Analog bus connection Yes
1DC or AC RMS voltage, channel-to-channel or channel-to-earth
2At analog bus connector
350 Ohm source, 50 Ohm load, differential measurements verified with 4-port network analyzer (Sdd21)
4Limited to 6 W of channel resistance power loss per module
5Speeds are with an external DMM with 4-1/2 digits, delay 0, display off, autozero off, and within bank
6Includes 0.5°C error temperature reference sensor and 0.3°C terminal block isothermal gradient error.
See User’s Guide for information on supported external reference sensors.
Measurement Accuracy For accuracy measurement specification, combine the DMM offset with the switch
offset. Bandwidth of the switch may offset the accuracy of the AC measurement.
Product Specifications
Command Execution Time in msec:
GPIB LAN
Open or Close 4.7 5.3
Init/*WAI 1.9 3
Close/Init/Open 12.4 14
Scanning rates with external DMM (includes switch, DMM measure time and I/O time with Agilent 34401A, 34410A, 34411A)
Scanning channels GPIB LAN (w/ VXI 11)
ch/s ch/s
Scanning DCV or Ohms 100 100
Scanning ACV 75 75
Scanning temperature 100 100
Scan triggering
Source Interval, external, software
Scan count 1 to 50,000 or continuous
Scan interval 0 to 99 hours; 1 ms step size
Channel delay 0 to 60 seconds per channel; 1 ms step size
External trig delay <2 ms.
External trig jitter <2 ms
Memory
States 5 instrument states with user label in non-volatile memory
General specifications
Power supply Universal 100 V to 240 V ±10%
Power line frequency 50 Hz to 60 Hz ±10% automatically sensed
Power consumption 15 VA
Operating Environment Full accuracy for 0°C to 55°C
Full accuracy to 80% R.H. at 40 °C
Pollution degree 1 of IEC 61010-1
Storage environment -40°C to 70°C
Dimensions (H x W x L) 40.9 x 212.3 x 379.3 mm
1.61 x 8.36 x 14.93 in
Weight 3.8 kg, 8.4 lbs
Safety conforms to CSA, UL/IEC/EN 61010-1
EMC conforms to IEC/EN 61326-1, CISPR 11
Warranty 1 year
6
Product Specifications (continued)
Software
Agilent connectivity Agilent I/O Libraries Suite 14 or greater (E2094N)
software included
Minimum system requirements
PC hardware Intel Pentium 100 MHz, 64 Mbyte RAM, 210 Mbyte disk space
Display 800x600, 256 colors, CD-ROM drive
Operating system1Windows®98 SE/NT/2000/XP
Computer interfaces
Standard LAN 10BaseT/100BaseTx
Optional IEEE 488.2 GPIB
Software driver support for programming languages
Software drivers IVI-C and IVI-COM for Windows NT®/2000/XP
LabVIEW
Compatible with programming tools and environments
Agilent VEE Pro
T&M Toolkit
(reqs Visual Studio.NET)
National Instruments TestStand
Measurement Studio
LabWindows/CVI
LabVIEW
Switch Executive
Microsoft Visual Studio.NET®
C/C++
Visual Basic 6®
1Load I/O Libraries Version M for Windows NT support or version 14.0 for Windows 98 SE support
Product Specifications (continued)
7
Ordering information
L4421A 40-chan armature multiplexer
Includes User’s guide on CD,
power cord, and Quick Start
package
Option -GPIB
Adds GPIB interface
Option 0B0
Deletes printed manual set,
full documentation included
on CD ROM
Option ABA
English printed manual set
Connection Options
Select terminal block for
discrete wiring, cables or
connector kits. Cables and
connector kits require 2 per
instrument.
34921T
Terminal block with temp
reference for 34921A and
L4421A 40-Ch Multiplexer
Y1135A
1.5 m 50-pin Dsub,
M/F twisted pair with
outer shield cable – 300 V
Y1136A
3 m 50-pin Dsub, M/F
twisted pair with outer
shield cable – 300 V
Y1139A
Solder cup connector kit
with female 50-pin Dsub
Other accessories
Y1160A
Rack mount kit for
L4400 series instruments-
racks 2 instruments side-by-side
on sliding tray
34307A
10-pack of J-type
thermocouples
34308A
5-pack of 10 k thermistors
For additional information
please visit:
http://www.agilent.com/find/L4421A
Related Agilent literature
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5988-6302EN
Agilent VEE Pro
5989-1441EN
Agilent W1140A-TKT
T&M Toolkit 2.0 with
Test Automation
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Agilent E2094N
I/O Libraries Suite 14
8
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Product specifications and descriptions in
this document subject to change without
notice.
Microsoft®and Windows®are U.S. registered
trademarks of Microsoft®Corporation
LabVIEWTM is a U.S. registered trademark of
National Instruments Corporation
© Agilent Technologies, Inc. 2006
Printed in the USA, March 14, 2006
5989-4825EN
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