BNC 525 User manual

Operating Manual Version 1.0
Model 525
Pulse Generator
Berkeley Nucleonics Corporation
2955 Kerner Blvd.
San Rafael, CA 94901
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Web: www.berkeleynucleonics.com

Contents
PULSE GENERATOR ................................................................................................................................................................ 1
1INTRODUCTION .............................................................................................................................................................. 4
1.1 TECHNICAL SUPPORT.............................................................................................................................................................4
1.2 WARRANTY.........................................................................................................................................................................4
1.3 PACKAGE CONTENTS .............................................................................................................................................................4
2SAFETY ISSUES................................................................................................................................................................ 5
3CERTIFICATE OF CONFORMANCE.................................................................................................................................... 6
4FRONT & BACK PANEL OVERVIEW.................................................................................................................................. 7
4.1 FRONT PANEL......................................................................................................................................................................7
4.1.1 Indicators.................................................................................................................................................................7
4.1.2 Run/Stop/Power Button ..........................................................................................................................................7
4.2 BACK PANEL........................................................................................................................................................................7
4.2.1 Indicators.................................................................................................................................................................7
4.2.2 BNC Output Connectors...........................................................................................................................................8
4.2.3 USB ..........................................................................................................................................................................8
4.2.4 Run/Stop/Power Button ..........................................................................................................................................8
4.2.5 Gate/Trigger Input...................................................................................................................................................8
4.2.6 Clock In /Clock Out...................................................................................................................................................8
5PULSE CONCEPTS AND PULSE GENERATOR OPERATIONS ............................................................................................... 9
5.1 COUNTER ARCHITECTURE OVERVIEW .......................................................................................................................................9
5.2 SYSTEM TIMER FUNCTIONS ....................................................................................................................................................9
5.3 CHANNEL TIMER FUNCTIONS ..................................................................................................................................................9
5.4 DIGITAL OUTPUT MULTIPLEXER ............................................................................................................................................10
5.5 DEPENDENT &INDEPENDENT TIMING EVENTS (SYNC FUNCTION) ................................................................................................10
5.6 NAVIGATING THE 525.........................................................................................................................................................10
5.7 ENABLING SYSTEM OUTPUT .................................................................................................................................................10
6525 SETUP .....................................................................................................................................................................11
6.1 OVERVIEW ........................................................................................................................................................................11
6.2 POWER ............................................................................................................................................................................11
6.3 COMMUNICATION ..............................................................................................................................................................11
6.4 USB ................................................................................................................................................................................11
6.4.1 Driver Installation (Windows XP)...........................................................................................................................11
6.4.2 Driver Installation (Windows 7 and Greater) ........................................................................................................12
7525 APPLICATION ..........................................................................................................................................................13
7.1 525 APPLICATION OVERVIEW...............................................................................................................................................13
7.2 BASIC OPERATION ..............................................................................................................................................................14
7.2.1 System Section.......................................................................................................................................................14
7.2.2 Channels Section....................................................................................................................................................15
7.2.3 Options Section......................................................................................................................................................16
7.3 COMMAND TERMINAL.........................................................................................................................................................17
7.4 PARAMETER STORAGE.........................................................................................................................................................18
7.4.1 Saving Custom Settings to a Bin ............................................................................................................................18
7.4.2 Recalling Custom Settings from a Bin....................................................................................................................18
8OPERATING THE 525......................................................................................................................................................19
8.1 NORMAL INTERNAL RATE GENERATOR OPERATION...................................................................................................................19
8.1.1 Continuous Mode ..................................................................................................................................................19
8.1.2 Single Shot Mode...................................................................................................................................................20
8.1.3 System Burst Mode Function.................................................................................................................................20

8.1.4 System Duty Cycle Function...................................................................................................................................20
8.2 CHANNEL TIMER OVERVIEW .................................................................................................................................................20
8.2.1 Channel Normal Function ......................................................................................................................................21
8.2.2 Channel Single Shot Function ................................................................................................................................21
8.2.3 Channel Burst Mode ..............................................................................................................................................21
8.2.4 Channel Duty Cycle Mode......................................................................................................................................22
8.3 EXTERNAL INPUT OVERVIEW.................................................................................................................................................22
8.3.1 Generate a Pulse on Every Trigger Input ...............................................................................................................22
8.3.2 Using the External Gate to Control the System .....................................................................................................22
8.3.3 Using the External Gate to Control the Channel....................................................................................................23
8.3.4 Using the External Re-Arm ....................................................................................................................................23
8.4 OUTPUT EXAMPLES ............................................................................................................................................................24
9PROGRAMMING THE 525 ..............................................................................................................................................25
9.1 PERSONAL COMPUTER TO 525 COMMUNICATION ....................................................................................................................25
9.2 USB INTERFACE OVERVIEW..................................................................................................................................................25
9.3 PROGRAMMING COMMAND TYPES AND FORMAT .....................................................................................................................25
9.3.1 Line Termination....................................................................................................................................................26
9.3.2 IEEE 488.2 Common Command Format.................................................................................................................26
9.3.3 SCPI Command Keywords ......................................................................................................................................26
9.3.4 SCPI Command Format..........................................................................................................................................26
9.3.5 SCPI Keyword Separator ........................................................................................................................................27
9.3.6 SCPI Optional Keywords.........................................................................................................................................27
9.3.7 SCPI Parameter Types............................................................................................................................................27
9.3.8 Error Codes ............................................................................................................................................................27
9.3.9 Programming Examples ........................................................................................................................................28
9.4 525 SCPI COMMAND SUMMARY..........................................................................................................................................29
9.5 IEEE 488.2 COMMON COMMANDS ......................................................................................................................................33
10 APPENDIX A –SPECIFICATIONS..................................................................................................................................34
10.1 525 SPECIFICATIONS...........................................................................................................................................................34
11 APPENDIX D –TZ50 (IMPEDANCE MATCH OPTION) ...................................................................................................37
11.1 TZ50 OVERVIEW ...............................................................................................................................................................37
11.1.1 TZ50 Specifications ................................................................................................................................................37
11.1.2 Terminating Into 50 Ohms.....................................................................................................................................37
11.1.3 Terminating Into High Impedance.........................................................................................................................38
12 APPENDIX E –SAFETY SYMBOLS ................................................................................................................................39
12.1 SAFETY MARKING SYMBOLS .................................................................................................................................................39

1 Introduction
This manual is a reference designed to familiarize you with the BNC Model 525 Series Pulse Generator and is
arranged so that you can easily find the information you‟re looking for. Generally, each topic has its own section and
no section assumes that you‟ve read anything else in the manual.
Technical specifications including electrical ratings and weight are included within the manual. See the Table of
Contents to locate the specifications and other product information. The following classifications are standard
across all BNC Test and Measurement products.
Indoor use only
Ordinary Protection: This product is NOT protected against the harmful ingress of moisture.
Class 1 Equipment (grounded type)
Main supply voltage fluctuations are not to exceed +/-10% of the nominal supply voltage.
Pollution Degree II
Installation (overvoltage) Category II for transient overvoltage events
Maximum Relative Humidity: 0-80% RH, non-condensing
Operating temperature range of 0 oC to 40 oC
Storage and transportation temperature of -40 oC to 70 oC
Maximum altitude: 2000 m (6562 ft.)
This equipment is suitable for continuous operation.
Cleaning Instructions: Light dusting with cloth damp with water and/or usage of compressed air is all that is
needed.
1.1 Technical Support
For questions or comments about operating the Model 525 our technical staff can be reached via one of the
following methods:
• Phone - [phone]
• Fax - [phone]
• Email – [e-mail]
• Internet - www.berkeleynucleonics.com
1.2 Warranty
In addition to a 30-day money back guarantee, the model 525 has a two-year limited warranty from the date of
delivery. This warranty covers defects in materials and workmanship. If repairs are required during the warranty
period, contact the factory for component replacement or shipping instructions. Include the serial number of the
instrument. This warranty is void if the unit is repaired or altered by others than those authorized by Berkeley
Nucleonics Corporation.
1.3 Package Contents
The box you receive should contain the following:
•Model 525 Digital Delay / Pulse Generator
•USB Cord
•Disk that includes:
Operating Manual
Software Drivers
Application Software
Contact BNC [phone] if any parts are missing.

2 Safety Issues
Normal use of test equipment presents a certain amount of danger due to electrical shock because it may be
necessary for testing to be performed where voltage is exposed.
An electrical shock causing 10 milliamps of current to pass through the heart will stop most human
heartbeats. Voltage as low as 35 VDC or 35 VRMS AC should be considered dangerous and hazardous, as it
can produce a lethal current under certain conditions. Higher voltages pose an even greater threat because
such voltage can easily produce a lethal current. Your normal work habits should include all accepted
practices that will prevent contact with exposed high voltage and steer current away from your heart in case
of accidental contact with a high voltage. You will significantly reduce the risk factor if you know and observe
the following safety precautions:
If possible, familiarize yourself with the equipment being tested and the location of its high-voltage
points. However, remember that high voltage may appear at unexpected points in defective
equipment.
Do not expose high voltage needlessly. Remove housing and covers only when necessary. Turn off
equipment while making test connections in high- voltage circuits. Discharge high-voltage
capacitors after shutting down power.
When testing AC powered equipment, remember that AC line voltage is usually present on power
input circuits, such as the on-off switch, fuses, power transformer, etc.
Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work
surface on which to place equipment. Make certain such surfaces are not damp or wet.
Use the time-proven “one hand in the pocket” technique while handling an instrument probe. Be
particularly careful to avoid contact with metal objects that could provide a good ground return path.
Never work alone. Someone should always be nearby to render aid if necessary. Training in
CPR first aid is highly recommended.

3 Certificate of Conformance

4 Front & Back Panel Overview
4.1 Front Panel
4.1.1 Indicators
A total of up to 9 separate LED indicators are included on the front panel of the 525. The following details the
type of indication they represent.
Power
Indicates the unit is powered on.
Channel A-F
Indicates which channels are in the enabled state.
Active
Ext In
Indicates the unit is armed and/or channels are actively
pulsing (or waiting to be triggered).
Indicates external mode is either set to gate or trigger.
4.1.2 Run/Stop/Power Button
The Run/Stop button serves the dual purpose of both powering on/off the unit as well as enabling/disabling the
system output. It should be noted that only a short press is needed to both turn on and arm/disarm the unit.
The button needs to be pressed and held for approximately 1 second in order to power off the unit. In the
power off sequence the active settings are saved and reloaded when the unit is power back on.
The following image represents the front panel of a 525.
Figure 3.1 - 525 Front Panel
4.2 Back Panel
4.2.1 Indicators
A total of up to 10 separate LED indicators are included on the back panel of the 525.The following further
details the type of indication they represent.
PWR
Indicates the unit is powered on.
Channel A-F
Indicates which channels are in the enabled state.

Active
Indicates the armed channels are actively pulsing (or waiting
to be triggered).
Gate/Trig
Indicates which mode the external input is in. If neither is
illuminated, the unit is in internally triggered mode.
4.2.2 BNC Output Connectors
Standard BNC connectors are found on the back panel which output the pulses for their respective channel.
4.2.3 USB
A “Standard B” female type USB connector is found on the back panel. This provides power to the unit as well
as communication (on standard units).
4.2.4 Run/Stop/Power Button
The Run/Stop button serves the dual purpose of both powering on/off the unit as well as enabling/disabling the
system output. It should be noted that only a short press is needed to both turn on and arm/disarm the unit.
The button needs to be pressed and held for approximately 1 second in order to power off the unit. In the
power off sequence the active settings are saved and reloaded when the unit is power back on.
4.2.5 Gate/Trigger Input
The Gate/Trig input allows external signals to either trigger or gate output events depending on setup.
4.2.6 Clock In /Clock Out
The Clock In allows external synchronization with other instruments. Various clock frequencies can be applied to the
input when the unit is set to external clock mode. The Clock Out will output various frequencies as well as a T0
signal. These outputs are user selectable.
The following image represents the back panel of a 525.
Figure 3.2- 525 Back Panel

5 Pulse Concepts and Pulse Generator Operations
5.1 Counter Architecture Overview
*Start source is:
Run/Stop button/function in Internal Modes
External input in External Trigger modes
*TRG command via Serial access
**Channels are armed by the Run/Stop function (external button or through 525 application). In
single shot and burst modes channels may be rearmed by pressing the RUN button again.
5.2 System Timer Functions
The System Timer functions as a non-retriggerable, multi-vibrator pulse generator. This means that once
started, depending on the mode, the timer will produce pulses continuously. Before pulses can be generated,
the timer must be armed and then receive a start pulse. Arming the counter is done by enabling the Run/Stop
function by either the external button or through the 525 application. With external trigger disabled, the
Run/Stop function also generates the start command for the counter. With external trigger enabled, the
external trigger provides the start pulse. In either case, once started, the counter operation is determined by
the System Mode Generator. Standard modes include:
Continuous
Once started T0 pulses are generated continuously.
Single Shot
One T0 pulse is generated for each start command.
Burst
„N‟ T0 pulses are generated for each start command.
Duty Cycle
Once started T0 pulses cycle on and off continuously.
The T0pulse is distributed to all of the start inputs of the Channel Timers and Mode Generators.
5.3 Channel Timer Functions
The Channel Timer functions as a non-retriggerable, delayed, one shot pulse generator. This means that the
timer will only generate one delayed pulse for every start pulse received. Once the channel timer has started
counting, additional start pulses will be ignored until the pulse has been completed (non-retriggerable). The
start pulse for each channel is provided by the internal T0pulse generated by the internal system timer.
Whether or not a pulse is generated for each T0pulse is determined by the Channel Mode Generator.

Standard modes include:
Normal
A pulse is generated for each T0pulse.
Single Shot
One pulse is generated for the first T0pulse, after which
the output is inhibited.
Burst
„N‟ number of pulses are generated for each T0pulse, after
which the output is inhibited.
Duty Cycle
„N‟ number of pulses are produced, one for each T0pulse,
after which „M‟ number of pulses will be inhibited, one for
each T0pulse. The cycle is then repeated for each
subsequent T0pulse.
A Different mode may be selected for each channel, allowing a wide variety of output combinations. Each
output may also be independently disabled or gated (using the external gate input).
5.4 Digital Output Multiplexer
The outputs of each of the Channel Timers are routed to a set of multiplexers. This allows routing of any or all
Channel Timers to any or all of the units‟ outputs. In the normal mode of operation, the output of the n th Channel
Timer is routed to the nth output connector. As an example, if a double pulse is required on Channel A, one can
multiplex the Channel A timer with the Channel B timer, then adjust each timer to provide the necessary pulses.
Only the timing parameters are multiplexed together, not the actual output amplitudes.
5.5 Dependent & Independent Timing Events (Sync Function)
The 525 allows the user to control the relationship between the Channel Timers by setting the sync source for
each timer. Independent events are all timed relative to the internal T0start pulse. Dependent events may be
linked together by setting the sync source to the controlling event. This allows the instrument to match the timed
events and adjustments can be made in one event without detuning the timing between it and the dependent
event.
5.6 Navigating the 525
Primary control of the 525 is carried out either through the 525 application (see 525 application Menus) or
through unit specific commands using a terminal program via USB (see Programming the 525). The Run/Stop
buttons found on either side of the 525 serve the purpose of both power on/off as well as enabling/disabling the
system output.
5.7 Enabling System Output
The Run/Stop button found on both the front and back panel of the 525 is used to arm the system. With
external trigger disabled, the button will arm and start pulse output. With external trigger enabled, the button
will arm the pulse generator. Pulse outputs then starts after the first valid trigger input. Pressing the Run/Stop
button a second time disables the pulse generator.