Avtech AVIR-1-B User manual

INSTRUCTIONS
MODEL AVIR-1-B
0 TO 200 VOLT
HIGH PERFORMANCE PULSE GENERATOR
WITH IEEE 488.2 AND RS-232 CONTROL
SERIAL NUMBER: ____________
A V T E C H E L E C T R O S Y S T E M S L T D .
N A N O S E C O N D W A V E F O R M E L E C T R O N I C S
S I N C E 1 7 5
P.O. BOX 265
OGDENSBURG, NY
U.S.A. 1366 -0265
TEL: [phone] (USA & Canada) or [phone] (Intl)
FAX: [phone] (USA & Canada) or [phone] (Intl)
[e-mail] - http://www.avtechpulse.com/
X
BOX 5120, LCD MERIVALE
OTTAWA, ONTARIO
CANADA K2C 3H4

WARRANTY
Avtech Electrosystems Ltd. warrants products of its manufacture to be free
from defects in material and workmanship under conditions of normal use. If,
within one year after delivery to the original owner, and after prepaid return by
the original owner, this Avtech product is found to be defective, Avtech shall at
its option repair or replace said defective item. This warranty does not apply to
units which have been dissembled, modified or subjected to conditions
exceeding the applicable specifications or ratings. This warranty is the extent
of the obligation assumed by Avtech with respect to this product and no other
warranty or guarantee is either expressed or implied.
TECHNICAL SUPPORT
Phone: [phone] (USA & Canada) or [phone] (International)
Fax: [phone] (USA & Canada) or [phone] (International)
E-mail: [e-mail]
World Wide Web: http://www.avtechpulse.com
2

TABLE OF CONTENTS
WARRANTY......................................................................................................................2
TECHNICAL SUPPORT....................................................................................................2
TABLE OF CONTENTS....................................................................................................3
INTRODUCTION...............................................................................................................5
AVAILABLE OPTIONS............................................................................................................5
SPECIFICATIONS.............................................................................................................6
REGULATORY NOTES....................................................................................................7
FCC PART 18..........................................................................................................................7
EC DECLARATION OF CONFORMITY..................................................................................7
DIRECTIVE 2002/95/EC (RoHS).............................................................................................8
DIRECTIVE 2002/9 /EC (WEEE)............................................................................................8
AC POWER SUPPLY REGULATORY NOTES.......................................................................9
INSTALLATION..............................................................................................................10
VISUAL CHECK.................................................................................................................... 10
POWER RATINGS................................................................................................................10
CONNECTION TO THE POWER SUPPLY...........................................................................10
PROTECTION FROM ELECTRIC SHOCK...........................................................................11
ENVIRONMENTAL CONDITIONS.........................................................................................12
LABVIEW DRIVERS..............................................................................................................12
FUSES.............................................................................................................................13
AC FUSE REPLACEMENT...................................................................................................13
DC FUSE REPLACEMENT...................................................................................................14
FUSE RATINGS....................................................................................................................14
FRONT PANEL CONTROLS..........................................................................................15
REAR PANEL CONTROLS............................................................................................17
GENERAL INFORMATION.............................................................................................19
BASIC PULSE CONTROL....................................................................................................19
TRIGGER MODES................................................................................................................20
GATING MODES................................................................................................................... 21
OPTIONAL FEATURES..................................................................................................22
RACK MOUNTING, -R5 OPTION..........................................................................................22
DC OFFSET, -OS OPTION...................................................................................................22
3

MONITOR OUTPUT, -M OPTION..........................................................................................22
ELECTRONIC AMPLITUDE CONTROL, -EA OPTION.........................................................22
PROTECTING YOUR INSTRUMENT.............................................................................23
TURN OFF INSTRUMENT WHEN NOT IN USE....................................................................23
DO NOT EXCEED 50 kHz.....................................................................................................23
USE A 50Ω LOAD.................................................................................................................23
OPERATIONAL CHECK.................................................................................................2
PROGRAMMING YOUR PULSE GENERATOR............................................................28
KEY PROGRAMMING COMMANDS.....................................................................................28
ALL PROGRAMMING COMMANDS......................................................................................29
MECHANICAL INFORMATION......................................................................................31
TOP COVER REMOVAL.......................................................................................................31
RACK MOUNTING................................................................................................................31
ELECTROMAGNETIC INTERFERENCE..............................................................................31
MAINTENANCE..............................................................................................................32
REGULAR MAINTENANCE...................................................................................................32
CLEANING............................................................................................................................ 32
WIRING DIAGRAMS.......................................................................................................33
WIRING OF AC POWER.......................................................................................................33
PCB 158J - LOW VOLTAGE DC POWER SUPPLY, 1/3......................................................34
PCB 158J - LOW VOLTAGE DC POWER SUPPLY, 2/3......................................................35
PCB 158J - LOW VOLTAGE DC POWER SUPPLY, 3/3......................................................3
PCB 1 8B - HIGH VOLTAGE DC POWER SUPPLY............................................................37
PCB 20 A - PRF LIMITER....................................................................................................38
PCB 104D - KEYPAD / DISPLAY BOARD, 1/3.....................................................................39
PCB 104D - KEYPAD / DISPLAY BOARD, 2/3.....................................................................40
PCB 104D - KEYPAD / DISPLAY BOARD, 3/3.....................................................................41
MAIN WIRING........................................................................................................................42
PERFORMANCE CHECKSHEET................................................................................... 3
Manual Reference: /fileserver2/officefiles/instructword/avir/AVIR-1-B,edition1.odt.
Last modified February 2 , 2012.
Copyright © 2012 Avtech Electrosystems Ltd, All Rights Reserved.
4

INTRODUCTION
The AVIR-1-B is a high performance, GPIB and RS232-equipped instrument capable of
generating 200V into 50Ω loads at repetition rates up to 20 kHz. The output pulse width
is variable from 2 to 5 ns. The sync delay is variable up to ±1 second. The rise time is
less than 1 ns (20%-80%), and the fall time is less than 1.8 ns (80%-20%).
Instruments with the "-P" model suffix can generate 0 to +200V, whereas instruments
with the "-N" model suffix can generate 0 to -200V. Instruments with the "-PN" suffix can
generate both polarities.
A 50 Ohm load is required for proper operation. The output stage may be damaged if
the output is not terminated into a 50Ω load.
The AVIR-1-B is a highly flexible instrument. Aside from the internal trigger source, it
can also be triggered or gated by external TTL-level signals. A front-panel pushbutton
or a computer command can also be used to trigger the instrument.
The AVIR-1-B features front panel keyboard and adjust knob control of the output pulse
parameters along with a four line by 40-character backlit LCD display of the output
amplitude, pulse width, pulse repetition frequency, and delay. The instrument includes
memory to store up to four complete instrument setups. The operator may use the front
panel or the computer interface to store a complete “snapshot” of all key instrument
settings, and recall this setup at a later time.
This instrument is intended for use in research, development, test and calibration
laboratories by qualified personnel.
AVAILABLE OPTIONS
The AVIR-1-B is available with several options:
-EA Option: the amplitude can be controlled by an externally generated 0 to +10V
analog control voltage.
-M Option: a monitor output is provided.
-OS Option: an externally generated DC offset can be added to the output.
-R5 Option: A rack mounting kit is available. The "-R5" rack mount kit may be installed
after first removing the one Phillips screw on the side panel adjacent to the front
handle.
-TNT Option: Adds a rear-panel Ethernet connector, providing Telnet-based remote
control from a network.
5

SPECIFICATIONS
Model: AVIR-1-B2
Amplitude3,4,5, : 0 to 200 Volts (50Ω load required)
Pulse width (FWHM)4: 2 - 5 ns
Max. rise time (20%-80%): 1 ns
Max. fall time (80%-20%): 1.8 ns
PRF: 0 to 50 kHz
Polarity6: Positive or negative or both (specify)
GPIB and
RS-232 control2:Standard on -B units.
LabView Drivers: -B units only: check http://www.avtechpulse.com/labview
for availability and downloads
Internet control:
(Telnet & Web)
Optional7.
See http://www.avtechpulse.com/options/tnt for details.
Propagation delay: ≤ 100 ns (Ext trig in to pulse out)
Jitter: ± 35ps ± 0.015% of sync delay (Ext trig in to pulse out)
DC offset or
bias insertion:
Optional8. Apply required DC offset or bias in the range of
± 50 Volts (250 mA max) to back panel solder terminal..
Trigger required: Ext trig mode: + 5 Volts, 50 ns or wider (TTL)
Sync delay: Sync out to pulse out, variable 0 to ± 500 ns
Sync output +3 Volts, 200 ns, will drive 50 Ohm loads
Connectors: Out: SMA, Trig/Sync, Gate (-B only): BNC
Power requirement: 100 - 240 Volts, 50 - 60 Hz
Dimensions: H x W x D: 100 × 430 × 375 mm (3. × 17 × 14.8”)
Chassis material: cast aluminum frame & handles, blue vinyl on aluminum cover plates
Rack-mount kit: Optional. To specify, add the -R5 suffix to the model number.
Temperature range: +5°C to +40°C
1) -C suffix indicates stand-alone lab instrument with internal clock and line powering.
2) -B suffix indicates IEEE-488.2 GPIB and RS-232 control of amplitude, pulse width, PRF and delay (see http://www.avtechpulse.com/gpib for details).
3) For electronic control (0 to +10V) of amplitude, suffix the model number with -EA. Includes standard front-panel controls. Not available on AVIR-4
models.
4) For 10-turn dial control of pulse width (or amplitude) suffix model number with -PWT (or -AT). Not applicable for -B units.
5) For operation at amplitudes of less than 10% of full-scale, best results will be obtained by setting the amplitude near full-scale and using external
attenuators on the output.
6) Indicate desired polarity by suffixing model number with -P or -N (i.e. positive or negative) or -PN for dual polarity option. Polarity reversal is
achieved by means of a two-position switch.
7) Add the suffix -TNT to the model number to specify the Internet control (Telnet and Web) option.
8) For DC offset option suffix model number with -OS.
) The maximum amplitude decreases by 15% for repetition rates above 30 kHz. The maximum amplitude also decreases by an additional 15% for
pulse widths below 3 ns.
6

REGULATORY NOTES
FCC PART 18
This device complies with part 18 of the FCC rules for non-consumer industrial,
scientific and medical (ISM) equipment.
This instrument is enclosed in a rugged metal chassis and uses a filtered power entry
module (where applicable). The main output signal is provided on a shielded connector
that is intended to be used with shielded coaxial cabling and a shielded load. Under
these conditions, the interference potential of this instrument is low.
If interference is observed, check that appropriate well-shielded cabling is used on the
output connectors. Contact Avtech ([e-mail]) for advice if you are unsure
of the most appropriate cabling. Also, check that your load is adequately shielded. It
may be necessary to enclose the load in a metal enclosure.
If any of the connectors on the instrument are unused, they should be covered with
shielded metal “dust caps” to reduce the interference potential.
This instrument does not normally require regular maintenance to minimize interference
potential. However, if loose hardware or connectors are noted, they should be
tightened. Contact Avtech ([e-mail]) if you require assistance.
EC DECLARATION OF CONFORMITY
We Avtech Electrosystems Ltd.
P.O. Box 5120, LCD Merivale
Ottawa, Ontario
Canada K2C 3H4
declare that this pulse generator meets the intent of Directive 2004/108/EG for
Electromagnetic Compatibility. Compliance pertains to the following specifications as
listed in the official Journal of the European Communities:
EN 50081-1 Emission
EN 50082-1 Immunity
7

and that this pulse generator meets the intent of the Low Voltage Directive 72/23/EEC
as amended by 3/68/EEC. Compliance pertains to the following specifications as
listed in the official Journal of the European Communities:
EN 61010-1:2001 Safety requirements for electrical equipment for
measurement, control, and laboratory use
DIRECTIVE 2002/ 5/EC (RoHS)
This instrument is exempt from Directive 2002/ 5/EC of the European Parliament and
of the Council of 27 January 2003 on the Restriction of the use of certain Hazardous
Substances (RoHS) in electrical and electronic equipment. Specifically, Avtech
instruments are considered "Monitoring and control instruments" (Category ) as
defined in Annex 1A of Directive 2002/ 6/EC. The Directive 2002/ 5/EC only applies to
Directive 2002/ 6/EC categories 1-7 and 10, as stated in the "Article 2 - Scope" section
of Directive 2002/ 5/EC.
DIRECTIVE 2002/ 6/EC (WEEE)
European customers who have purchased this equipment directly from Avtech will have
completed a “WEEE Responsibility Agreement” form, accepting responsibility for
WEEE compliance (as mandated in Directive 2002/ 6/EC of the European Union and
local laws) on behalf of the customer, as provided for under Article of Directive
2002/ 6/EC.
Customers who have purchased Avtech equipment through local representatives
should consult with the representative to determine who has responsibility for WEEE
compliance. Normally, such responsibilities with lie with the representative, unless
other arrangements (under Article ) have been made.
Requirements for WEEE compliance may include registration of products with local
governments, reporting of recycling activities to local governments, and financing of
recycling activities.
8

AC POWER SUPPLY REGULATORY NOTES
This instrument converts the AC input power to the +24V DC voltage that powers the
internal circuitry of this instrument using a Tamura AAD130SD-60-A switching power
supply. According to the manufacturer, the Tamura AAD130SD-60-A has the following
certifications:
UL60 50-1
IEC60 50 -1
CSA C22.2 No. 60 50- 1
EN60 50 -1
and is compliant with:
EN61000-3-2
EN61000-4-2 Level 2
EN61000-4-2 Level 3 (Air Only)
EN61000-4-4 Level 3
EN61000-4-5 Level 3
EN61000-4-11
CISPR 11 and 22 FCC Part 15 Class B (conducted)

INSTALLATION
VISUAL CHECK
After unpacking the instrument, examine to ensure that it has not been damaged in
shipment. Visually inspect all connectors, knobs, liquid crystal displays (LCDs), and the
handles. Confirm that a power cord, a GPIB cable, and two instrumentation manuals
(this manual and the “Programming Manual for -B Instruments”) are with the instrument.
If the instrument has been damaged, file a claim immediately with the company that
transported the instrument.
POWER RATINGS
This instrument is intended to operate from 100 - 240 V, 50 - 60 Hz.
The maximum power consumption is 57 Watts. Please see the “FUSES” section for
information about the appropriate AC and DC fuses.
This instrument is an “Installation Category II” instrument, intended for operation from a
normal single-phase supply.
CONNECTION TO THE POWER SUPPLY
An IEC-320 three-pronged recessed male socket is provided on the back panel for AC
power connection to the instrument. One end of the detachable power cord that is
supplied with the instrument plugs into this socket. The other end of the detachable
power cord plugs into the local mains supply. Use only the cable supplied with the
instrument. The mains supply must be earthed, and the cord used to connect the
instrument to the mains supply must provide an earth connection. (The supplied cord
does this.)
Warning: Failure to use a grounded outlet may result in injury or death due to
electric shock. This product uses a power cord with a ground connection. It must be
connected to a properly grounded outlet. The instrument chassis is connected to the
ground wire in the power cord.
The table below describes the power cord that is normally supplied with this instrument,
depending on the destination region:
10

Destination Region Description Option Manufacturer Part Number
United Kingdom, Hong Kong,
Singapore, Malaysia
BS 1363,
230V, 50 Hz -AC00 Qualtek 370001-E01
Australia, New Zealand AS 3112:2000,
230-240V, 50 Hz -AC01 Qualtek 374003-A01
Continental Europe, Korea,
Indonesia, Russia
European CEE 7/7
“Schuko” 230V, 50 Hz -AC02 Qualtek 364002-D01
North America, Taiwan NEMA 5-15,
120V, 60 Hz -AC03 Qualtek 312007-01
Switzerland SEV 1011,
230V, 50 Hz -AC06 Qualtek 378001-E01
South Africa, India SABS 164-1,
220-250V, 50 Hz -AC17 Volex 2131H 10 C3
Japan JIS 8303,
100V, 50-60 Hz -AC18 Qualtek 3 7002-01
Israel SI 32,
220V, 50 Hz -AC1 Qualtek 3 8001-01
China GB 1002-1,
220V, 50 Hz -AC22 Volex 2137H 10 C3
PROTECTION FROM ELECTRIC SHOCK
Operators of this instrument must be protected from electric shock at all times. The
owner must ensure that operators are prevented access and/or are insulated from
every connection point. In some cases, connections must be exposed to potential
human contact. Operators must be trained to protect themselves from the risk of
electric shock. This instrument is intended for use by qualified personnel who recognize
shock hazards and are familiar with safety precautions required to avoid possibly injury.
In particular, operators should:
1. Keep exposed high-voltage wiring to an absolute minimum.
2. Wherever possible, use shielded connectors and cabling.
3. Connect and disconnect loads and cables only when the instrument is turned off.
4. Keep in mind that all cables, connectors, oscilloscope probes, and loads must
have an appropriate voltage rating.
5. Do not attempt any repairs on the instrument, beyond the fuse replacement
procedures described in this manual. Contact Avtech technical support (see
page 2 for contact information) if the instrument requires servicing. Service is to
be performed solely by qualified service personnel.
11

ENVIRONMENTAL CONDITIONS
This instrument is intended for use under the following conditions:
1. indoor use;
2. altitude up to 2 000 m;
3. temperature 5 °C to 40 °C;
4. maximum relative humidity 80 % for temperatures up to 31 °C decreasing
linearly to 50 % relative humidity at 40 °C;
5. Mains supply voltage fluctuations up to ±10 % of the nominal voltage;
6. no pollution or only dry, non-conductive pollution.
LABVIEW DRIVERS
A LabVIEW driver for this instrument is available for download on the Avtech web site,
at http://www.avtechpulse.com/labview. A copy is also available in National
Instruments' Instrument Driver Library at http://www.natinst.com/.
12

FUSES
This instrument contains four fuses. All are accessible from the rear-panel. Two protect
the AC prime power input, and two protect the internal DC power supplies. The
locations of the fuses on the rear panel are shown in the figure below:
AC FUSE REPLACEMENT
To physically access the AC fuses, the power cord must be detached from the rear
panel of the instrument. The fuse drawer may then be extracted using a small flat-head
screwdriver, as shown below:
13
Fuses #1 and #2
(AC fuses)
Fuse #4
(DC fuse)
Fuse #3
(DC fuse)
Fuse
Drawer
Pry out the fuse
drawer using a
screwdriver

DC FUSE REPLACEMENT
The DC fuses may be replaced by inserting the tip of a flat-head screwdriver into the
fuse holder slot, and rotating the slot counter-clockwise. The fuse and its carrier will
then pop out.
FUSE RATINGS
The following table lists the required fuses:
Fuses
Nominal
Mains
Voltage
Rating Case Size
Recommended Replacement Part
Littelfuse Part
Number
Digi-Key Stock
Number
#1, #2 (AC) 100-240V 0.5A, 250V,
Time-Delay 5×20 mm 0218.500HXP F2416-ND
#3 (DC) N/A 1.6A, 250V,
Time-Delay 5×20 mm 021801.6HXP F2424-ND
#4 (DC) N/A 0.5A, 250V,
Time-Delay 5×20 mm 0218.500HXP F2416-ND
The recommended fuse manufacturer is Littelfuse (http://www.littelfuse.com).
Replacement fuses may be easily obtained from Digi-Key (http://www.digikey.com) and
other distributors.
14

FRONT PANEL CONTROLS
1. POWER Switch . This is the main power switch. When turning the instrument on,
there may be a delay of several seconds before the instrument appears to respond.
2. OVERLOAD Indicator . When the instrument is powered, this indicator is normally
green, indicating normal operation. If this indicator is yellow, an internal automatic
overload protection circuit has been tripped. If the unit is overloaded (by operating
at an exceedingly high duty cycle or by operating into a very low impedance), the
protective circuit will disable the output of the instrument and turn the indicator light
yellow. The light will stay yellow (i.e. output disabled) for about 5 seconds after
which the instrument will attempt to re-enable the output (i.e. light green) for about 1
second. If the overload condition persists, the output will be disabled again (i.e. light
yellow) for another 5 seconds. If the overload condition has been removed, the
instrument will resume normal operation.
This overload indicator may flash yellow briefly at start-up. This is not a cause for
concern.
Note that the output stage will safely withstand a short-circuited load condition.
3. OUT CONNECTO R . This BNC connector provides the main output signal, into load
impedances of 50Ω .
Caution: Voltages as high as ±200V may be present on the center conductor of
this output connector. Avoid touching this conductor. Connect to this connector
using standard coaxial cable, to ensure that the center conductor is not exposed.
4. SYNC OUT . This connector supplies a SYNC output that can be used to trigger
other equipment, particularly oscilloscopes. This signal leads (or lags) the main
output by a duration set by the "DELAY" controls and has an approximate amplitude
of +3 Volts to RL > 50Ω with a pulse width of approximately 100 ns.
5. LIQUID CRYSTAL DISPLAY (LCD) . This LCD is used in conjunction with the
keypad to change the instrument settings. Normally, the main menu is displayed,
15
2
3
4
5
6
1

which lists the key adjustable parameters and their current values. The
“Programming Manual for -B Instruments” describes the menus and submenus in
detail.
6. KEYPAD .
Control Name Function
MOVE This moves the arrow pointer on the display.
CHANGE This is used to enter the submenu, or to select the operating
mode, pointed to by the arrow pointer.
×10 If one of the adjustable numeric parameters is displayed, this
increases the setting by a factor of ten.
÷10 If one of the adjustable numeric parameters is displayed, this
decreases the setting by a factor of ten.
+/- If one of the adjustable numeric parameters is displayed, and
this parameter can be both positive or negative, this changes
the sign of the parameter.
EXTRA FINE This changes the step size of the ADJUST knob. In the extra-
fine mode, the step size is twenty times finer than in the normal
mode. This button switches between the two step sizes.
ADJUST This large knob adjusts the value of any displayed numeric
adjustable values, such as frequency, pulse width, etc. The
adjust step size is set by the "EXTRA FINE" button.
When the main menu is displayed, this knob can be used to
move the arrow pointer.
16

REAR PANEL CONTROLS
1. AC POWER INPUT . An IEC-320 C14 three-pronged recessed male socket is
provided on the back panel for AC power connection to the instrument. One end of
the detachable power cord that is supplied with the instrument plugs into this
socket.
2. AC FUSE DRAWER . The two fuses that protect the AC input are located in this
drawer. Please see the “FUSES” section of this manual for more information.
3. DC FUSES . These two fuses protect the internal DC power supplies. Please see the
“FUSES” sections of this manual for more information.
4. GATE . This TTL-level (0 and +5V) logic input can be used to gate the triggering of
the instrument. This input can be either active high or active low, depending on the
front panel settings or programming commands. (The instrument triggers normally
when this input is unconnected). When set to active high mode, this input is pulled-
down to ground by a 1 kΩ resistor. When set to active low mode, this input is pulled-
up to +5V by a 1 kΩ resistor.
5. TRIG . This TTL-level (0 and +5V) logic input can be used to trigger the instrument,
if the instrument is set to triggering externally. The instrument triggers on the rising
edge of this input. The input impedance of this input is 1 kΩ. (Depending on the
length of cable attached to this input, and the source driving it, it may be desirable
to add a coaxial 50 Ohm terminator to this input to provide a proper transmission
line termination. The Pasternack (www.pasternack.com) PE6008-50 BNC feed-thru
50 Ohm terminator is suggested for this purpose.)
6. GPIB Connector . A standard GPIB cable can be attached to this connector to allow
the instrument to be computer-controlled. See the “Programming Manual for -B
Instruments” for more details on GPIB control.
17
GATE
TRIG
AMP RS-232
GPIB
LAN
GRN=LNK
YEL=ACT
MON OS GND
2
3
6
1
45 8
7
10
11

7. RS-232 Connector. A standard serial cable with a 25-pin male connector can be
attached to this connector to allow the instrument to be computer-controlled. See the
“Programming Manual for -B Instruments” for more details on RS-232 control.
8. LAN Connector and Indicator . (Optional feature. Present on -TNT units only.) The
-TNT option "Internet-enables" Avtech pulse generators by adding this standard
Ethernet port to the rear panel, in addition to the IEEE-488.2 GPIB and RS-232 ports
normally found on "-B" units. Commands are sent using the standard Telnet protocol.
The SCPI-compliant command set is the same as that used for GPIB and RS-232
control. The -TNT option uses the Dynamic Host Configuration Protocol (DHCP) to
obtain its network address. A DHCP server must be present on the local network for
the -TNT option to operate properly.
. AMP Connector . (Optional feature. Present on "-EA" units only.) The output amplitude
can be set to track the voltage on this input. Zero Volts in corresponds to zero
amplitude output, and +10V in corresponds to maximum amplitude out. This mode is
activated by selecting "Ext Control" on the front-panel amplitude menu, or with the
"source:voltage external" command.
10.MON Connector . (Optional feature. Present on "-M" units only.) The monitor output
provides an attenuated replica (20 dB down) of the voltage on the main output. The
monitor output is designed to operate into a 50 Ohm load.
11.OS Connector . (Optional feature. Present on "-OS" units only.) The desired DC offset
is applied to this connector. Internally, it is connected to the output centre conductor
via a high quality RF inductor. Do not exceed ±50V, 250 mA. When not used, the OS
input should be connected to ground.
18

GENERAL INFORMATION
BASIC PULSE CONTROL
This instrument can be triggered by its own internal clock or by an external TTL trigger
signal. In either case, two output channels respond to the trigger: OUT and SYNC.
•OUT. This is the main output. The maximum output voltage is 200V.
•SYNC. The SYNC pulse is a fixed-width TTL-level reference pulse used to
trigger oscilloscopes or other measurement systems. When the delay is set to a
positive value the SYNC pulse precedes the OUT pulse. When the delay is set
to a negative value the SYNC pulse follows the OUT pulse.
These pulses are illustrated below, assuming internal triggering and a positive delay.
All waveforms are shown with positive amplitudes.
Figure A
If the delay is negative, the order of the SYNC and OUT pulses is reversed:
Figure B
1
SYNC OUT
(generated by the
internal oscillator)
100 ns, FIXED
MAIN OUTPUT
PULSE WIDTHDELAY > 0
AMPLITUDE,
VARIABLE
3V, FIXED
SYNC OUT
(generated by the
internal oscillator)
100 ns, FIXED
MAIN OUTPUT
PULSE WIDTH
DELAY < 0
AMPLITUDE,
VARIABLE
3V, FIXED

The next figure illustrates the relationship between the signal when an external TTL-
level trigger is used:
Figure C
As before, if the delay is negative, the order of the SYNC and OUT pulses is reversed.
In general, the delay, pulse width, and frequency (when in the internal mode), of the
OUT pulse can be varied with front panel controls or via the GPIB or RS-232 computer
interfaces.
TRIGGER MODES
This instrument has four trigger modes:
•Internal Trigger: the instrument controls the trigger frequency, and generates the
clock internally.
•External Trigger: the instrument is triggered by an external TTL-level clock on the
back-panel TRIG connector.
•Manual Trigger: the instrument is triggered by the front-panel “SINGLE PULSE”
pushbutton.
•Hold Trigger: the instrument is set to not trigger at all.
These modes can be selected using the front panel trigger menu, or by using the
appropriate programming commands. (See the “Programming Manual for -B
Instruments” for more details.)
20
SYNC OUT
100 ns, FIXED
MAIN OUTPUT
PULSE WIDTHDELAY > 0
AMPLITUDE,
VARIABLE
3V, FIXED
> 50 ns
TTL LEVELS
(0V and 3V-5V)
TRIG
(external input)
PROPAGATION DELAY (FIXED)