AVTECH ELECTROSYSTEMS LTD. AV-1021-B User manual

INSTRUCTIONS
MODEL AV-1021-B
0 TO ±10 VOLTS, 10 MHz
GENERAL-PURPOSE
LAB PULSE GENERATOR
WITH IEEE 488.2 AND RS-232 CONTROL
SERIAL NUMBER 13991
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 9 7 5
[e-mail]
http //www.avtechpulse.com/
Tel [phone] (USA & Canada) or [phone] (Intl)
Fax [phone] (USA & Canada) or [phone] (Intl)
BOX 5120, LCD MERIVALE
OTTAWA, CANADA K2C3H5

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 2011/65/EU (RoHS)............................................................................................8
DIRECTIVE 2002/ 6/EC (WEEE)............................................................................................8
FIRMWARE LICENSING.........................................................................................................
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....................................................................................................1
TRIGGER MODES................................................................................................................ 22
PULSE WIDTH MODES........................................................................................................23
GATING MODES...................................................................................................................23
OPERATIONAL CHEC .................................................................................................24
PROGRAMMING YOUR PULSE GENERATOR............................................................28
3

KEY PROGRAMMING COMMANDS....................................................................................28
ALL PROGRAMMING COMMANDS.....................................................................................2
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 158R4 - LOW VOLTAGE POWER SUPPLY................................................................34
PCB 104F - KEYPAD / DISPLAY BOARD, 1/3....................................................................35
PCB 104F - KEYPAD / DISPLAY BOARD, 2/3....................................................................36
PCB 104F - KEYPAD / DISPLAY BOARD, 3/3....................................................................37
MAIN WIRING.......................................................................................................................38
PERFORMANCE CHEC SHEET.................................................................................39
Manual Reference /fileserver2/officefiles/instructword/av-1020/av-1021-b,ed9.odt.
Last modified April 29, 2020.
Copyright © 2020 Avtech Electrosystems Ltd, All Rights Reserved.
4

INTRODUCTION
The AV-1021-B is a high performance, GPIB and RS232-equipped instrument capable
of generating ±10V into 50Ω loads at repetition rates up to 5 MHz. The pulse width is
variable from 20 ns to 500 ms. The delay between the SYNC output and the main
output can be varied from 0 to ±0.5 seconds. Rise and fall times are fixed at less than
10 ns. Two logic-level outputs (normal and complemented) are also provided. These
may be set to operate at TTL or ECL logic levels.
The AV-1021-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. In the external
trigger mode, the output pulse width can be set by the pulse generator, or it can be set
to follow the input trigger’s pulse width. The AV-1021-B can generate single or double
pulse outputs.
The source resistance can be set at either 2 or 50Ω. In the 2Ω setting, the maximum
voltage available from the main output is ±10V. The pulse amplitude can be varied
between 0 and ±10V, as can the DC offset voltage. In the 50Ω setting the maximum
voltage available (into a 50Ω load) is ±5V. The 50Ω setting is useful for transmission
line backmatching.
The AV-1021-B features front panel keyboard and adjust knob control of the output
pulse parameters along with a four line by 40 character back-lit LCD display of the
output amplitude, polarity, pulse width, pulse repetition frequency, source resistance
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 and development laboratories.
AVAILABLE OPTIONS
-TR Option This reduces the rise and fall times of the main output from 10 ns to 5 ns.
-R5 Option This is the optional rack-mounting kit. The R5 rack-mount kit may also be
ordered separately.
5

SPECIFICATIONS
Model AV-1021-B
Outputs One main output,
One logic output,
One logic-complement output.
Logic output levels May be set to operate at TTL or ECL levels.
This setting applies to both the logic and logic-complement outputs.
Amplitude and peak output
(to 50 Ohms)1
Main output (when ZOUT=2Ω) < ±0.5 to ±10 V
Main output (when ZOUT=50Ω) < ±0.25 to ±5 V
Logic outputs (nominally) TTL 0 and +5V,
ECL -0.8V and -1.6V.
Pulse repetition frequency (PRF) 1 Hz to 5 MHz
Pulse width (FWHM) 20 ns to 0.5 sec, or DC
(subject to duty cycle limits)
Rise and fall times
(20%-80%)
Main ≤ 10 ns standard, 5 ns optional2
TTL ≤ 5 ns
ECL ≤ 2 ns
Adjustable DC offset10 to ±10 V for ZOUT=2Ω,
0 to ±5 V for ZOUT=50Ω
Parasitic DC offset < ±100 mV
Source impedance ZOUT Main output 2Ω or 50Ω, switchable.
This is the impedance in series with the output internally (not the load impedance).
Required load impedance ≥ 50Ω
Duty cycle (maximum) 70% (100% in PW DC mode).
Additionally, there must be at least 100 ns between the
trailing edge of one pulse and the leading edge of the next pulse.
This “dead-time” requirement will reduce the maximum duty cycle at high PRFs.
Waveform aberrations Overshoot and ringing are less than ≤ 15% at amplitudes of
1 V and higher with outputs terminating in 50Ω.
Propagation delay < 200 ns (Ext trig in to pulse out, with delay set to zero)
Trigger modes Internal trigger, external trigger (TTL level pulse, > 10 ns, 1 kΩ input impedance),
front-panel “Single Pulse” pushbutton, or single pulse trigger via computer command.
Trigger required (Gate in) TTL, synchronous or asynchronous, active high or low
Delay jitter ≤ ± 35ps ± 0.015% RMS (sync out to pulse out)
Delay 0 to ±1 sec (sync out to pulse out)
Sync output > +3 Volts, > 50 ns, will drive 50 Ohm loads
Double pulse mode spacing 1 us to 1 second (measured between the two leading edges of the pulse doublet). Must not
exceed one-half of the period. There must be at least (PW + 100 ns) of “dead time” (no pulsing)
between the trailing edge of the first pulse and the leading edge of the second pulse. For instance,
if the pulse width is 1 us, the programmed delay between leading edges must be greater than
1 us (the pulse width) + 1.1 us (the minimum dead time) = 2.1 us,
and the period must be greater than 4.2 us.
Signal connectors BNC. Main outputs and Sync are on the front panel.
Logic outputs & Gate & Trig inputs are on the rear.
GPIB and RS-232 control Included. See http //www.avtechpulse.com/gpib for details.
LabView Drivers Check http //www.avtechpulse.com/labview for availability and downloads
Ethernet port, for remote control
using VXI-11.3, ssh, telnet, & web
Included. Recommended as a modern alternative to GPIB / RS-232.
See http //www.avtechpulse.com/options/vxi for details.
Settings resolution The resolution of the timing parameters (pulse width, delay, period) varies, but is always better
than 0.15% of (|set value| + 20 ns).
The amplitude resolution is < 0.1% of the maximum amplitude.
Settings accuracy Typically ± 3% (plus ±0.1V or ± 2 ns) after 10 minute warmup. For high-accuracy applications
requiring traceable calibration, verify the output parameters with a calibrated oscilloscope.
Power requirement 100 - 240 Volts, 50 - 60 Hz
Dimensions, Weight, Chassis 100 x 430 x 375 mm (3.9” x 17” x 14.8”), 10 kg (22 lbs),
anodized aluminum with blue-gray plastic trim
Temperature range +5°C to +40°C
1) Peak output = amplitude + offset. The amplitude and offset can not be set to maximum at the same time, or the peak output rating will be exceeded.
2) Add the suffix -TR to the model number to specify the 5 ns rise time option.
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 (i[email protected]) if you require assistance.
EC DECLARATION OF CONFORMITY
We Avtech Electrosystems Ltd.
P.O. Box 5120, LCD Merivale
Ottawa, Ontario
Canada K2C 3H5
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 2006/95/EC.
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 2011/65/EU (RoHS)
We Avtech Electrosystems Ltd.
P.O. Box 5120, LCD Merivale
Ottawa, Ontario
Canada K2C 3H5
declare that, to the best of our knowledge, all electrical and electronic equipment (EEE)
sold by the company are in compliance with Directive 2011/65/EU of the European
Parliament and of the Council of 8 June 2011 on the restriction of the use of certain
hazardous substances in electrical and electronic equipment (also known as “RoHS
Recast”). In addition, this declaration of conformity is issued under the sole
responsibility of Avtech Electrosystems Ltd. Specifically, products manufactured do not
contain the substances listed in the table below in concentrations greater than the listed
maximum value.
Material/Substance Threshold level
Lead (Pb) < 1000 ppm (0.1% by mass)
Mercury (Hg) < 1000 ppm (0.1% by mass)
Hexavalent Chromium (Cr6+) < 1000 ppm (0.1% by mass)
Polybrominated Biphenyls (PBB) < 1000 ppm (0.1% by mass)
Polybrominated Diphenyl ethers (PBDE) < 1000 ppm (0.1% by mass)
Cadmium (Cd) < 100 ppm (0.01% by mass)
Bis(2-ethylhexyl) phthalate (DEHP) < 1000 ppm (0.1% by mass)
Butyl benzyl phthalate (BBP) < 1000 ppm (0.1% by mass)
Dibutyl phthalate (DBP) < 1000 ppm (0.1% by mass)
Diisobutyl phthalate (DIBP) < 1000 ppm (0.1% by mass)
DIRECTIVE 2002/96/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 2002/96/EC of the European Union and local
8

laws) on behalf of the customer, as provided for under Article 9 of Directive
2002/96/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 9) 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.
FIRMWARE LICENSING
Instruments with firmware versions 5.00 or higher use open-source software internally.
Some of this software requires that the source code be made available to the user as a
condition of its licensing. This source code is available upon request (contact
[email protected]om).
Earlier firmware versions do not contain any open source software.
9

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 397002-01
Israel SI 32,
220V, 50 Hz -AC19 Qualtek 398001-01
China GB 1002-1 / 2099-1,
220V, 50 Hz -AC22 Qualtek 399012-01
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
Fuses #1 and #2
(AC fuses)
Fuse #4
(DC fuse)
Fuse #
(DC fuse)
Fuse
Drawer
Pry out the fuse
drawer using a
screwdriver.
13

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 Not used.
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 is normally a delay of 10 seconds before anything is shown on the main
display, as the internal operating system boots up.
If the main menu does not appear after 30 seconds, turn off the instrument and
leave it off for at least 60 seconds before applying power again.
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.
3. OUT CONNECTOR . This BNC connector provides the main output signal, into load
impedances of 50Ω or higher. It can generate voltages of up to ±10V.
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 > 1kΩ with a pulse width of approximately 50 ns.
5. LOGIC Output . The signal on this output has approximately the timing parameters
as the main output (i.e. frequency, pulse width, and delay) but the amplitude is fixed
at either TTL logic levels (0 and +5V, approximately) or ECL logic levels
(-1.6V and -0.8V, approximately), depending on the settings. When using this
27
3
4
15
8
15
6

output, it is recommended that it be terminated with a 50Ω load.
6. LOGIC-Complement Output . The signal on this output is the logical complement of
the signal on the LOGIC output (item 4). That is, the high and low logic levels are
reversed.
7. LIQUID CRYSTAL DISPLAY (LCD) . This LCD is used in conjunction with the
keypad to change the instrument settings. Normally, the main menu is displayed,
which lists the key adjustable parameters and their current values. The
“Programming Manual for -B Instruments” describes the menus and submenus in
detail.
8. 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
Note: some connectors may be in different positions than shown above, depending on
the exact combination of options ordered.
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 Pomona Electronics 4119-50 BNC feed-thru 50 Ohm terminator is
suggested for this purpose.)
2
6 7
GATE
RS-232
GPIB
TRIG
17
8
931
45

When triggering externally, the instrument can be set such that the output pulse
width tracks the pulse width on this input, or the output pulse width can be set
independently.
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.
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. A user
name (“admin”) and a password (“default”, as shipped from the factory) are required
when logging into a serial terminal session. The internal controller attempts to auto-
sense the parity setting. It may be necessary to send a few return characters before
attempting a login in order to provide enough data to allow this auto-sensing to work.
(A standard Linux “agetty” process is used to implement serial control internally.) See
the “Programming Manual for -B Instruments” for more details on RS-232 control.
8. Network Connector . This Ethernet connector allows the instrument to be remotely
controlled using the VXI-11.3, ssh (secure shell), telnet, and http (web) protocols. See
the “Programming Manual for -B Instruments” for more details.
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, four output channels respond to the trigger OUT, SYNC, LOGIC,
and LOGIC-Complement.
OUT. This is the main output. The pulse width, amplitude, and offset are all
adjustable. The maximum output voltage is ±10V. (This voltage is reduced by a
factor of two if the output impedance is set at 50Ω, and a 50Ω load is used.)
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.
LOGIC. The signal on this output has approximately the timing parameters as
the main output (i.e. frequency, pulse width, and delay) but the amplitude is fixed
at either TTL logic levels (0 and +5V, approximately) or ECL logic levels
(-1.6V and -0.8V, approximately), depending on the settings. When using this
output, it is recommended that it be terminated with a 50Ω load.
LOGIC-Complement Output. The signal on this output is the logical complement
of the signal on the LOGIC output. That is, the high and low logic levels are
reversed.
These pulses are illustrated below, assuming internal triggering and a positive delay
19

If the delay is negative, the order of the SYNC and OUT pulses is reversed
20
SYNC OUT
(generated by the
internal oscillator)
50 ns, FIXED
MAIN OUTPUT
PULSE WIDTHDELAY > 0
AMPLITUDE, VARIABLE
2V, FIXED
OFFSET, VARIABLE
ZERO VOLTS
+5V (TTL) or -0.8V (ECL)
0V (TTL) or -1.6V (ECL)
LOGIC OUTPUT
+5V (TTL) or -0.8V (ECL)
0V (TTL) or -1.6V (ECL)
LOGIC OUTPUT
SYNC OUT
(generated by the
internal oscillator)
50 ns, FIXED
MAIN OUTPUT
PULSE WIDTH
DELAY < 0
AMPLITUDE, VARIABLE
3V, FIXED
OFFSET, VARIABLE
ZERO VOLTS
+5V (TTL) or -0.8V (ECL)
0V (TTL) or -1.6V (ECL)
LOGIC OUTPUT
+5V (TTL) or -0.8V (ECL)
0V (TTL) or -1.6V (ECL)
LOGIC OUTPUT