5 Commonwealth Ave
Woburn, MA 01801
Phone 781-665-1400
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com
Digital Storage Oscilloscope
User Manual
Model 2194
4
�
I ,.
.
Norm
_
gle
Sin
t
�
•
al
,
Safety Summary
The following safety precautions apply to both operating and maintenance personnel and must be followed during all
phases of operation, service, and repair of this instrument.
Before applying power to this instrument:
• Read and understand the safety and operational information in this manual.
• Apply all the listed safety precautions.
• Verify that the voltage selector at the line power cord input is set to the correct line voltage. Operating the instrument
at an incorrect line voltage will void the warranty.
• Make all connections to the instrument before applying power.
• Do not operate the instrument in ways not specied by this manual or by B&K Precision.
Failure to comply with these precautions or with warnings elsewhere in this manual violates the safety standards of design,
manufacture, and intended use of the instrument. B&K Precision assumes no liability for a customer’s failure to comply
with these requirements.
2
Category rating
The IEC 61010 standard denes safety category ratings that specify the amount of electrical energy available and the
voltage impulses that may occur on electrical conductors associated with these category ratings. The category rating is
a Roman numeral of I, II, III, or IV. This rating is also accompanied by a maximum voltage of the circuit to be tested,
which denes the voltage impulses expected and required insulation clearances. These categories are:
Category I (CAT I): Measurement instruments whose measurement inputs are not intended to be connected to the
mains supply. The voltages in the environment are typically derived from a limited-energy transformer or a battery.
Category II (CAT II): Measurement instruments whose measurement inputs are meant to be connected to the mains
supply at a standard wall outlet or similar sources. Example measurement environments are portable
tools and household appliances.
Category III (CAT III): Measurement instruments whose measurement inputs are meant to be connected to the mains
installation of a building. Examples are measurements inside a building’s circuit breaker panel
or the wiring of permanently-installed motors.
Category IV (CAT IV): Measurement instruments whose measurement inputs are meant to be connected to the primary
power entering a building or other outdoor wiring.
Do not use this instrument in an electrical environment with a higher category rating than what is specied in this manual
for this instrument.
You must ensure that each accessory you use with this instrument has a category rating equal to or higher than the
instrument’s category rating to maintain the instrument’s category rating. Failure to do so will lower the category rating
of the measuring system.
Electrical Power
This instrument is intended to be powered from a CATEGORY II mains power environment. The mains power should be
115 V RMS or 230 V RMS. Use only the power cord supplied with the instrument and ensure it is appropriate for your
country of use.
Ground the Instrument
To minimize shock hazard, the instrument chassis and cabinet must be connected to an electrical safety ground. This
instrument is grounded through the ground conductor of the supplied, three-conductor AC line power cable. The power
cable must be plugged into an approved three-conductor electrical outlet. The power jack and mating plug of the power
cable meet IEC safety standards.
Do not alter or defeat the ground connection. Without the safety ground connection, all accessible conductive parts
(including control knobs) may provide an electric shock. Failure to use a properly-grounded approved outlet and the
recommended three-conductor AC line power cable may result in injury or death.
3
Unless otherwise stated, a ground connection on the instrument’s front or rear panel is for a reference of potential only
and is not to be used as a safety ground. Do not operate in an explosive or ammable atmosphere.
Do not operate the instrument in the presence of ammable gases or vapors, fumes, or nely-divided particulates.
The instrument is designed to be used in oce-type indoor environments. Do not operate the instrument
• In the presence of noxious, corrosive, or ammable fumes, gases, vapors, chemicals, or nely-divided particulates.
• In relative humidity conditions outside the instrument’s specications.
• In environments where there is a danger of any liquid being spilled on the instrument or where any liquid can condense
on the instrument.
• In air temperatures exceeding the specied operating temperatures.
• In atmospheric pressures outside the specied altitude limits or where the surrounding gas is not air.
• In environments with restricted cooling air ow, even if the air temperatures are within specications.
• In direct sunlight.
This instrument is intended to be used in an indoor pollution degree 2 environment. The operating temperature range is
0∘C to 40∘C and 20% to 80% relative humidity, with no condensation allowed. Measurements made by this instrument
may be outside specications if the instrument is used in non-oce-type environments. Such environments may include
rapid temperature or humidity changes, sunlight, vibration and/or mechanical shocks, acoustic noise, electrical noise,
strong electric elds, or strong magnetic elds.
Do not operate instrument if damaged
If the instrument is damaged, appears to be damaged, or if any liquid, chemical, or other material gets on or inside the
instrument, remove the instrument’s power cord, remove the instrument from service, label it as not to be operated,
and return the instrument to B&K Precision for repair. Notify B&K Precision of the nature of any contamination of the
instrument.
Clean the instrument only as instructed
Do not clean the instrument, its switches, or its terminals with contact cleaners, abrasives, lubricants, solvents, acids/bases,
or other such chemicals. Clean the instrument only with a clean dry lint-free cloth or as instructed in this manual. Not
for critical applications
This instrument is not authorized for use in contact with the human body or for use as a component in a life-support
device or system.
4
Do not touch live circuits
Instrument covers must not be removed by operating personnel. Component replacement and internal adjustments must
be made by qualied service-trained maintenance personnel who are aware of the hazards involved when the instrument’s
covers and shields are removed. Under certain conditions, even with the power cord removed, dangerous voltages may
exist when the covers are removed. To avoid injuries, always disconnect the power cord from the instrument, disconnect
all other connections (for example, test leads, computer interface cables, etc.), discharge all circuits, and verify there
are no hazardous voltages present on any conductors by measurements with a properly-operating voltage-sensing device
before touching any internal parts. Verify the voltage-sensing device is working properly before and after making the
measurements by testing with known-operating voltage sources and test for both DC and AC voltages. Do not attempt
any service or adjustment unless another person capable of rendering rst aid and resuscitation is present.
Do not insert any object into an instrument’s ventilation openings or other openings.
Hazardous voltages may be present in unexpected locations in circuitry being tested when a fault condition in the circuit
exists.
Fuse replacement must be done by qualied service-trained maintenance personnel who are aware of the instrument’s fuse
requirements and safe replacement procedures. Disconnect the instrument from the power line before replacing fuses.
Replace fuses only with new fuses of the fuse types, voltage ratings, and current ratings specied in this manual or on
the back of the instrument. Failure to do so may damage the instrument, lead to a safety hazard, or cause a re. Failure
to use the specied fuses will void the warranty.
Servicing
Do not substitute parts that are not approved by B&K Precision or modify this instrument. Return the instrument to
B&K Precision for service and repair to ensure that safety and performance features are maintained.
For continued safe use of the instrument
• Do not place heavy objects on the instrument.
• Do not obstruct cooling air ow to the instrument.
• Do not place a hot soldering iron on the instrument.
• Do not pull the instrument with the power cord, connected probe, or connected test lead.
• Do not move the instrument when a probe is connected to a circuit being tested.
Working Environment
5
Environment
This instrument is intended for indoor use and should be operated in a clean, dry environment.
Temperature
Operating: 0℃ to +40℃
Non-operation:-20℃ to +60℃
Note:
Direct sunlight, radiators, and other heat sources should be taken into account when assessing the ambient temperature.
Humidity
Operating: 85% RH, 40 ℃, 24 hours
Non-operating: 85% RH, 65 ℃, 24 hours
Altitude
Operating: less than 3 Km
Non-operation: less than 15 Km
Installation (overvoltage) Category
This product is powered by mains conforming to installation (overvoltage) category II.
Degree of Pollution
The oscilloscopes may be operated in environments of Pollution Degree II.
Note:
Degree of Pollution II refers to a working environment which is dry and non-conductive pollution occurs. Occasional
temporary conductivity caused by condensation is expected.
IP Rating
IP20 (as dened in IEC 60529).
Compliance Statements
Disposal of Old Electrical & Electronic Equipment (Applicable in the European Union and other European
countries with separate collection systems)
This product is subject to Directive 2002/96/EC of the European Parliament
and the Council of the European Union on waste electrical and electronic equipment
(WEEE), and in jurisdictions adopting that Directive, is marked as being put on the
market after August 13, 2005, and should not be disposed of as unsorted municipal
waste. Please utilize your local WEEE collection facilities in the disposition of this
product and otherwise observe all applicable requirements.
Safety Symbols
6
Symbol Description
indicates a hazardous situation which, if not avoided, will result in death or serious injury.
indicates a hazardous situation which, if not avoided, could result in death or serious injury
indicates a hazardous situation which, if not avoided, will result in minor or moderate injury
Refer to the text near the symbol.
Electric Shock hazard
Alternating current (AC)
Chassis ground
Earth ground
This is the In position of the power switch when instrument is ON.
This is the Out position of the power switch when instrument is OFF.
is used to address practices not related to physical injury.
Contents
1 General Information 11
1.1 Product Overview 11
1.2 Features 11
1.3 Contents 11
1.4 Dimensions 12
1.5 Front Panel Overview 13
1.6 Rear Panel Overview 14
1.7 Display Overview 15
2 Getting Started 16
2.1 Input Power Requirements 16
2.2 Fuse Requirements and Replacement 16
2.3 Preliminary Check 17
2.3.1 Verify AC Input Voltage 17
2.3.2 Connect Power 17
2.3.3 Self-Test 18
2.3.4 Self-Cal 18
2.3.5 Check Model and Firmware Version 18
2.3.6 Function Check 19
2.4 Probe Safety 20
3 Vertical Controls 22
3.1 Enable Channel 22
3.2 Channe Menu 22
3.2.1 Channel Coupling 23
3.2.2 Bandwidth Limit 23
3.2.3 Adjust 23
3.2.4 Probe 24
3.2.5 Unit 24
3.2.6 Deskew 25
3.2.7 Invert 25
3.2.8 Oset 25
3.2.9 Trace Visible/Hidden 26
4 Horizontal Control 27
4.1 Horizontal Scale 27
4.2 Zoom 27
4.3 Roll Mode 28
4.4 Trigger Delay 28
5 Sample Control 29
5.1 Run Control 29
5.2 Sampling Theory 29
5.3 Sample Rate 29
5.4 Bandwidth and Sample Rate 30
5.5 Memory Depth 31
5.6 Sampling Mode 32
5.7 Interpolation Method 32
5.8 Acquisition Mode 33
5.9 Average 35
5.10 Eres Acquisition 35
5.11 Horizontal Format 35
5.12 Sequence Mode 37
6 Trigger 38
6.1 Trigger Source 38
6.2 Trigger Mode 39
6.3 Trigger Level 40
6.4 Trigger Coupling 41
6.5 Trigger Holdo 42
6.6 Noise Rejection 43
6.7 Trigger Types 43
6.7.1 Edge Trigger 44
6.7.2 Slope Trigger 45
6.7.3
46
6.7.4 Video Trigger 48
6.7.5 Window Trigger 51
6.7.6 Interval Trigger 54
6.7.7 Dropout Trigger 56
6.7.8 Runt Trigger 58
6.7.9 Pattern Trigger 60
7 Serial Trigger and Decode 62
7.1 I2C Trigger and Serial Decode 62
7.1.1 Setup for I2C Signals 62
7.1.2 I2C Trigger 63
7.1.3 I2C Serial Decode 66
7.2 SPI Trigger and Serial Decode 67
7.2.1 Setup for SPI Signals 67
7.2.2 SPI Trigger 71
7.2.3 SPI Serial Decode 72
7.3 UART Trigger and Serial Decode 73
7.3.1 Setup for UART Signals 73
7.3.2 UART Trigger 74
7.3.3 UART Serial Decode 75
7.4 CAN Trigger and Serial Decode 77
7.4.1 Setup for CAN Signals 77
7.4.2 CAN Trigger 77
7.4.1 CAN Serial Decode 79
7.5 LIN Trigger and Serial Decode 80
7.5.1 Setup for LIN Signals 80
7.5.2 LIN Trigger 81
7.5.1 Interpreting LIN Decode 83
8
8 Reference Waveform 84
8.1 Save REF Waveform to Internal Memory 84
8.2 Display REF Waveform 84
8.3 Adjust REF Waveform 85
8.4 Clear Ref Waveform 85
9 Math 86
9.1 Units for Math Waveforms 86
9.2 Math Operators 87
9.2.1 Addition or Subtraction 87
9.2.2 Multiplication and Division 88
9.2.3 FFT Operation 89
9.3 Math Function Operation 93
9.3.1 Dierentiate 93
9.3.2 Integrate 94
9.3.3 Square Root 94
10 Cursors 96
10.1 X Cursors 96
10.2 Y Cursors 97
10.3 Make Cursor Measurements 98
11 Measure 99
11.1 Type of Measurement 99
11.1.1 Voltage Measurements 99
11.1.2 Time Measurements 101
11.1.3 Delay Measurements 101
11.2 Automatic Measurement 102
11.3 All Measurement 104
11.4 Gate Measurement 105
11.5 Clear Measurement 105
12 Display 106
12.1 Display Type 106
12.2 Color Display 107
12.3 Persistence 108
12.4 Clear Display 109
12.5 Grid Type 109
12.6 Intensity 109
12.7 Grid Brightness 109
12.8 Transparence 110
9
13 Save and Recall 111
13.1 Save Type 111
13.2 Internal Save and Recall 112
13.3 External Save and Recall 113
13.4 Disk Management 115
13.4.1 Create a New File or Folder 115
13.4.2 Delete a File or Folder 116
13.4.3 Rename a File or Folder 116
14 System Settings 117
14.1 View System Status 117
14.2 Self Cal 118
14.3 Quick-Cal 118
14.4 Sound 119
14.5 Language 119
14.6 Pass/Fail Test 119
14.6.1 Set and Perform a Pass/Fail Test 120
14.6.2 Save and Recall Test Mask 121
14.7 IO Set 123
14.7.1 LAN 123
14.7.2 USB Device 124
14.8 Update Firmware and Conguration 124
14.9 Do Self-Test 125
14.9.1 Screen Test 125
14.9.2 Keyboard Test 126
14.9.3 LED Test 127
14.10 Screen Saver 128
14.11 Reference Position 129
14.12 Power On Line 129
15 Search 130
15.1 Setting 130
15.2 Results 131
10
16 Navigate 133
16.1 Time Navigate 133
16.2 History Frame Navigate 133
16.3 Search Event Navigate 133
17 History 134
18 Factory Setup 135
19 Troubleshooting 136
20 Service Information 138
21 LIMITED THREE-YEAR WARRANTY 139
General Information
1.1 Product Overview
Figure 1.1 2194 Front View
The B&K Precision 2194 digital storage oscilloscope (DSO) is a portable benchtop instrument used for making measurements of signals and waveforms.
This oscilloscope provides 100 MHz of bandwidth in a 4-channel conguration with a maximum sample rate of 1 GSa/s
and best-in class memory depth of 14 Mpts.
1.2 Features
– 4 channels with 100 MHz bandwidth
– Single channel real-time sampling rate of up to 1 GSa/s
– 14 Mpts memory depth
– Standard USB host, USBTMC device, and LAN ports
1.3 Contents
Inspect the instrument mechanically and electrically upon receiving it. Unpack all items from the shipping carton, and
check for any obvious signs of physical damage that may have occurred during transportation. Report any damage to
the shipping agent immediately. Save the original packing carton for possible future reshipment. Every oscilloscope is
shipped with the following contents:
– 1 x 2194 Digital Storage Oscilloscope
– AC Power Cord
– USB type A to type B cable.
– 4 x 1:1/10:1 Passive Oscilloscope Probes
– Certicate of Calibration
– Test Report
General Information 12
Note:
Ensure the presence of all the items above. Contact the distributor if anything is missing.
1.4 Dimensions
The 2194 digital storage oscilloscope’s dimensions are approximately: 312.00 mm (12.28 in) x 151.00 mm (5.94 in) x
132.60 mm (5.22 in) (W x H x D).
Figure 1.2 Front View Dimensions
Figure 1.3 Top View Dimensions
General Information 13
1.5 Front Panel Overview
The front panel interface allows for control of the unit.
Figure 1.4 Front Panel
Item Name Description
1 LCD Display Visual presentation of the device function and measurements.
2 Intensity Adjust Universal knob.
3
4 Numeric Keypad Used to enter precise values
5 Rotary Knob Used to navigate menus or congure parameters
6 Navigation Keys
7 CH 2 Terminals Serves as output or input terminals of CH 2 depending on the set functionality
8 Function Keys Frequently used function such as Home, Trig, Menu, ESC, and On/O keys
9 CH 1 Terminals Serves as output or input of CH 1 depending on the set functionality
10 Softkeys Used to invoke any functions displayed above them.
11 Power Switch Power the unit ON or OFF
12 Horizontal Control
13 Auto Set the trigger mode to auto.
14 Menu On/O Enable/disable the menu bar.
15 Softkeys Used to invoke any functions displayed above them.
16 Print Shortcut key for the save function.
17 Input Channels Input channels (1 MΩ BNC)
18 Power Button Power the unit ON or OFF.
19 USB Host Port USB port used to connect ash drives. (Type A)
20
Common
Function Keys
Probe
Compensation
Used to invoke the functions displayed above them.
Used to navigate menus. The enter key can be used to select a menu or enter a parameter
Probe compensation/ground terminal.
Table 1.1 Front Panel
General Information 14
1.6 Rear Panel Overview
Figure 1.5 Rear Panel Overview
Item Name Description
1 Handle Handle for easy carrying of the instrument.
2 Safety Lock Hole
3 LAN Connect an ethernet cable to remotely control the unit over the network.
4 USB Interface Connect a USB type B to type A to remotely control the unit.
5
6
Pass/Fail or
Trigger Out
AC Power Input
& Fuse Box
Locks the instrument to a xed location using the security lock via the lock hole.
The lock is not included.
Output a signal that reects the current waveform capture rate of the oscilloscope at
each trigger or a pass/fail test pulse.
Houses the fuse as well as the AC input .
Table 1.2 Rear Panel
General Information 15
1.7 Display Overview
Figure 1.6 Display Overview
Item Name Description
1 Trigger Status Displays the trigger status.
2
3
4 Menu Bar Displays the available options in the selected menu.
USB Host
Port Indicator
LAN Port
Indicator
Indicates that a USB is connected to the instrument.
Indicates the status of the LAN connection.
Table 1.3 Display Overview
Getting Started
Before connecting and powering up the instrument, review the instructions in this chapter.
2.1 Input Power Requirements
The oscilloscope has a universal AC input that accepts line voltage and frequency input within:
100 - 240 V (+/- 10%), 50/60 Hz (+/- 5%)
100 - 127 B, 400 Hz
50 W Max
Before connecting to an AC outlet or external power source, be sure that the power switch is in the OFF position and
verify that the AC power cord, including the extension line, is compatible with the rated voltage/current and that there
is sucient circuit capacity for the power supply. Once veried, connect the cable rmly.
The included AC power cord is safety certied for this instrument operating in rated range. To change a cable or add
an extension cable, be sure that it can meet the required power ratings for this instrument. Any misuse with wrong or
unsafe cables will void the warranty.
SHOCK HAZARD:
The power cord provides a chassis ground through a third conductor. Verify that your power outlet is of the
three conductor type with the correct pin connected to earth ground.
2.2 Fuse Requirements and Replacement
For continued re protection at all line voltages replace only with a 1.25 A / 250 V "F" rated, 5 x 20 mm
fuse.
For safety, no power should be applied to the instrument while changing line voltage operation. Disconnect all
cables connected to the instrument before proceeding.
Getting Started 17
Check and/or Change Fuse
– Locate the fuse box next to the AC input connector in the rear panel. (See gure 1.5)
– Insert a small athead screwdriver into the fuse box slit to pull and slide out the fuse box as indicated below.
– Check and replace fuse if necessary. (See gure 2.1)
Figure 2.1 Fuse Removal
Any disassembling of the case or changing the fuse not performed by an authorized service technician will void
the warranty of the instrument
2.3 Preliminary Check
Complete the following steps to verify that the oscilloscope is ready for use.
2.3.1 Verify AC Input Voltage
Verify proper AC voltages are available to power the instrument.
The AC voltage range must meet the acceptable specication stated in section Input Power Requirements.
2.3.2 Connect Power
Connect the AC power cord to the AC receptacle in the rear panel and press the power switch to turn on the instrument.
The instrument will have a boot up screen while loading, after which the main screen will be displayed.
Getting Started 18
2.3.3 Self-Test
The instrument has 3 self-test option to test the screen ,keyboard, and the LED back light.
To perform the self-test, please refer to the Self Test section for further instructions.
2.3.4 Self-Cal
Self option runs an internal self-calibration procedure that will check and adjust the instrument. To perform the selfcalibration refer to the Self-Calibration section for further instructions.
2.3.5 Check Model and Firmware Version
The model and rmware version can be veried from within the menu system.
To view the model and rmware version:
Press the Utility button and use the softkeys to select the System Status option. The following information will be
displayed:
– Startup Times
– Software Version
– Uboot-Os Version
– FPGA Version
– Hardware Version
– Product Type
– Serial NO
Press the Single key to exit.
Figure 2.2 System Status
Getting Started 19
2.3.6 Function Check
Follow the steps below to do a quick check of the oscilloscope’s functionality.
1. Power on the oscilloscope. Press Default Setup to show the result of the self-check.
– The probe default attenuation is 1X.
2. Set the switch to 1X on the probe and connect the probe to channel 1.
– To do this align the slot in the probe connector with the key on the CH1 BNC, push to connect, and twist to the
right to lock the probe in place.
– Connect the probe tip and reference lead to the Probe Comp connectors.
3. Press the AUTO button to show the square wave with 1 kHz frequency and 3V peak to peak .
Figure 2.3 3 Vpp Square Wave
4. Repeat steps 1 to 3 for the remaining channels.
Getting Started 20
2.4 Probe Safety
A guard around the probe body provides a nger barrier for protection from electric shock.
Figure 2.4 Probe
Connect the probe to the oscilloscope and connect the ground terminal to the ground before you take any measurements.
Shock Hazard:
To avoid electric shock when using the probe, keep ngers behind the guard on the probe body. To avoid electric shock
while using the probe, do not touch metallic portions of the probe head while it is connected to a voltage source.
Connect the probe to the oscilloscope and connect the ground terminal to ground before you take any measurements.
Getting Started 21
Probe Attenuation
Probes are available with various attenuation factors which aect the vertical scale of the signal. The Probe Check
function veries that the probe attenuation option matches the attenuation of the probe.
Press CH 1 once to open the channel menu. Use the softkeys to navigate to page 1/2 and select the Probe option.
Select the probe option that matches the attenuation of the probe.
Note:
The default setting for the Probe option is 1 X.
Verify that the attenuation switch on the probe matches the Probe option in the oscilloscope. Switch settings are 1 X
and 10 X.
Probe Compensation
Before taking any measurements using a probe, verify the compensation of the probe and adjust it to match the channel
inputs.
To match your probe to the input channel:
1. Set the channel’s probe attenuation to 10X.
– Press the CH # key corresponding to the channel the probe is connected to.
– Use the softkeys to navigate to page 1.
– Use the softkeys to select Probe.
– Use the Intensity Adjust knob to select 10X.
2. Attach the probe tip to the Compensation Signal Output Terminal 3 V(Cal) connector and the reference lead to
the Probe Ground terminal connector.
– Press the Auto Setup key to display the square wave.
3. Check the shape of the displayed waveform.
Undercompensated Correctly Compensated Overcompensated
Figure 2.5 Probe Compensation
4. If necessary, adjust your probe’s compensation trimmer pot.
Vertical Controls
3.1 Enable Channel
The 2194 provides 4 analog input channels. To enable a channel press
the corresponding channel button located on the vertical controls.
The enabled channels can be veried on the right side of the display
screen.
To disable a channel:
Press the correponding channel key. Once the key has been highlighted
by the LED press the channel key again.
– Pressing the channel key of the currently selected channel once will
disable the channel.
and 2 Enabled
3.2 Channe Menu
Figure 3.2 shows the channel 2 menu that is displayed after pressing the CH 2 key.
Channel Menu Page 1/2
Channel Menu Page 2/2
Figure 3.2 CH 2 Menu
Channels 1
Figure 3.1 Enabled Channels
All Channels
Enabled
Vertical Controls 23
3.2.1 Channel Coupling
Coupling mode lters out the undesired signals.
Press the corresponding CH button, then use the softkeys to select Coupling.
Turn the Universal Knob to select the desired coupling method.
Note:
The current coupling method is displayed in the channel label at the right side of the screen. Pressing the Coupling
softkey continuously switches between the available coupling method.
• DC Coupling: The DC and AC components of the signal under test are both passed.
• AC Coupling: The DC components of the signal under test are blocked.
• GND Coupling: The DC and AC components of the signal under test are both blocked.
3.2.2 Bandwidth Limit
Sets the bandwidth limit to reduce display noise.
Press the CH button of the channel to be congured.
Use the softkeys to select BW Limit. (The bandwidth limit will alternate between Full and 20 M)
• Full: The high frequency components of the signal under test can pass the channel.
• 20 M: The high frequency components exceeding 20 MHz are attenuated.
3.2.3 Adjust
Adjust the vertical scale sensitivity of the selected channel.
The vertical scale is adjusted using the Vertical Variable Knob.
Press the CH button of the channel to be congured.
Use the softkeys to select Adjust. (The scale will alternate between Fine and Coarse)
If the amplitude of the input waveform is a little bit greater than the full scale under the current scale and the amplitude
would be a little bit lower if the next scale is used, ne adjustment can be used to improve the amplitude of waveform
display to view signal details.
• Fine adjustment: Adjust the vertical scale within a relatively smaller range to improve vertical resolution.
– For example: 2 V/div, 1.98V/div, 1.96V/div, 1.94 V/div, ...1 V/div.
• Coarse: Adjust the vertical scale in a 1-2-5 step.
– For example: 1 mV/div, 2 mV/div, 5 mV/div, 10 mV/div 200 mV/div, 500 mV/div,... 10 V/div.
The scale information in the channel label at the right side of the screen will change accordingly during the adjustment.
The adjustable range of the vertical scale is related to the probe ratio currently set.
Vertical Controls 24
Note:
Push the Vertical Variable Knob to quickly switch between Coarse and Fine adjustment.
3.2.4 Probe
Sets the probe attenuation factor to match the type of probe being used.
1. Press the CH button of the channel to be congured.
2. Use the softkeys to select Probe.
3. Use the softkeys to select Probe once more.
4. Use the Universal Knob to select the probe attenuation.
Table 3.1 shows the probe attenuation factors.
Setting Description
0.1X .01 : 1
0.2X .02 : 1
0.5X .05 : 1
1X 1 : 1
2X 2 : 1
5X 5 : 1
10X 10 : 1
... ...
10000X 10000 : 1
Table 3.1 Attenuation Factor
To customize the probe attenuation factor:
Press the Probe softkey, select Custom, and then press the Custom softkey.
Use the Universal Knob to set the desired probe attenuation ratio.
The range is [1E-6,1E6].
3.2.5 Unit
Selects the amplitude display unit for the selected channel.
The available units are V and A.
1. Press the CH button of the channel to be congured.
2. Use the softkeys to navigate to page 2/2.
3. Use the softkeys to select Unit and alternate between V and A.
The default unit is V.
Vertical Controls 25
3.2.6 Deskew
Adjust the dierence of phase between the channel.
The Valid range of each channel is±100 ns.
1. Press the CH button of the channel to be congured.
2. Use the softkeys to navigate to page 2/2.
3. Use the softkeys to select Deskew.
4. Turn the Universal Knob to change deskew.
– Pushing the Universal Knob open the keypad.
Figure 3.3 Deskew Keypad
3.2.7 Invert
Invert the voltage values of the displayed waveform.
Inverting a channel aects how the channel is displayed, all the results of any math function selected, and measurement
functions.
To invert the waveform:
– Press the CH button of the channel to be congured.
– Use the softkeys to navigate to page 2/2.
– Use the softkeys to toggle Invert On and O.
3.2.8 Oset
Oset the vertical position of the displayed waveform.
The Valid range of each channel is±100 V.
1. Press the CH button of the channel to be congured.
2. Use the softkeys to navigate to page 2/2.
Vertical Controls 26
3. Use the softkeys to select Oset.
4. Turn the Universal Knob to change deskew.
– Pushing the Universal Knob open the keypad.
Figure 3.4 Oset Keypad
Note:
The Vertical Position Knob can be used to oset the waveform’s vertical position without having to enter the channel’s menu. Pushing the Vertical Position Knob will zero vertical position.
3.2.9 Trace Visible/Hidden
Sets whether waveform of the selected channel is visible or hidden.
To toggle between visible and hidden:
1. Press the CH button of the channel to be congured.
2. Use the softkeys to navigate to page 2/2.
3. Use the softkeys to select Trace.
Horizontal Control
4.1 Horizontal Scale
Turn the Horizontal Scale Knob to adjust the horizontal time base. Turning the knob clockwise reduces the horizontal
time base. Turning the knob counterclockwise increases the time base.
The time base information at the upper left corner of the screen will change accordingly during the adjustment. The
2194 horizontal scale has a range from 2ns/div to 100s/div.
The Horizontal Scale Knob works (in the Normal time mode) while acquisitions are running or when they are stopped.
When in run mode, adjusting the horizontal scale knob changes the sample rate.
When stopped, adjusting the horizontal scale knob lets you zoom into acquired data.
4.2 Zoom
Zoom is a horizontally expanded version of the normal display. You can use Zoom to locate and horizontally expand part
of the normal window for a more detailed (higher- resolution) analysis of signals.
Press the Horizontal Scale Knob to enable the zoom function, and press the button again to turn disable the function.
When Zoom enabled, the display divides in half. The top half of the display shows the normal time base window and
the bottom half displays a faster Zoom time base window.
Figure 4.1 Zoom Mode
The area of the normal display that is expanded is outlined with a box and the rest of the normal display is ghosted. The
box shows the portion of the normal sweep that is expanded in the lower half.
Horizontal Control 28
To change the time base for the zoom window, turn the Horizontal Scale Knob. The Horizontal Position Knob sets
the left- to- right position of the zoom window.
The delay value, which is the time displayed relative to the trigger point is momentarily displayed in the upper right
corner of the display when the Horizontal Position Knob is turned. Negative delay values indicate you’re looking at a
portion of the waveform before the trigger event, and positive values indicate you’re looking at the waveform after the
trigger event.
To change the time base of the normal window, disable Zoom, then turn the Horizontal Scale Knob.
4.3 Roll Mode
In Roll mode the waveform moves slowly across the screen from right to left. It operates on time base settings of 50
ms/div and slower. If the current time base setting is faster than the 50 ms/div limit, it will be set to 50 ms/div when
Roll mode is entered.
In Roll mode there is no trigger. The xed reference point on the screen is the right edge of the screen and refers to
the current moment in time. Events that have occurred are scrolled to the left of the reference point. Since there is no
trigger, no pre- trigger information is available.
To enter Roll mode press the Roll button.
To stop the display, press the Run/Stop button.
To clear the display and restart an acquisition in Roll mode, press the Run/Stop button again.
To exit Roll mode press the Roll button.
Note:
Use Roll mode on low- frequency waveforms to yield a display much like a strip chart recorder.
4.4 Trigger Delay
Turn the Horizontal Position Knob on the front panel to adjust the trigger delay of the waveform. During the
modication, waveforms of all the channels would move left or right and the trigger delay message at the upper-right
corner of the screen would change accordingly. Press down this knob to quickly reset the trigger delay.
Changing the delay time moves the trigger point (solid inverted triangle) horizontally and indicates how far it is from the
time reference point. These reference points are indicated along the top of the display grid.
All events displayed left of the trigger point happened before the trigger occurred. These events are called pre- trigger
information, and they show events that led up to the trigger point.
Everything to the right of the trigger point is called post- trigger information. The amount of delay range (pre- trigger
and post- trigger information) available depends on the time/div selected and memory depth.
The position knob works (in Normal time mode) while acquisitions are running or when they are stopped.
Sample Control
5.1 Run Control
Press the Run/Stop or the Single key to stop the sampling system of the scope.
• Running: When the Run/Stop key is green, the oscilloscope is continuously acquiring data.
– To stop acquiring data, press the Run/Stop key.
– When the Run/Stop button is red, data acquisition is stopped.
– Red "Stop" text is displayed next to the trademark logo in the status line at the top of the display.
– To start acquiring data, press Run/Stop.
• Single: Clears the display, the trigger mode is temporarily set to Normal (to keep the oscilloscope from auto- triggering
immediately), the trigger circuitry is armed, the Single key is illuminated, and the oscilloscope waits until a user dened
trigger condition occurs before it displays a waveform.
– When the oscilloscope triggers, the single acquisition is displayed and the oscilloscope is stopped (the Run/Stop
button is illuminated in red).
– Press the Single key again to clear the current waveform and acquire a new one.
Note:
The Single run control lets you view a single shot events without subsequent waveform data overwriting the display. Use
Single when you want maximum memory depth for pan and zoom.
5.2 Sampling Theory
The Nyquist sampling theorem states that for a limited bandwidth (band- limited) signal with maximum frequency 𝑓
the equally spaced sampling frequency 𝑓𝑆must be greater than twice the maximum frequency 𝑓
the signal be uniquely reconstructed without aliasing.
𝑓
𝑀𝐴𝑋
= 𝐹
= 𝑁𝑦𝑞𝑢𝑖𝑠𝑡 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦(𝑓𝑁) = 𝑓𝑜𝑙𝑑𝑖𝑛𝑔 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
𝑆/2
, in order to have
𝑀𝐴𝑋
𝑀𝐴𝑋
5.3 Sample Rate
The maximum sample rate of the oscilloscope is 1G Sa/s. The actual sample rate of the oscilloscope is determined by
the horizontal scale. See section Horizontal Scale
The actual sample rate is displayed in the information area at the upper- right corner of the screen.
,
Figure 5.1 Actual Sample Rate
Sample Control 30
The sample rate aect the waveform in the following manner :
• Waveform Aliasing: Aliasing occurs when the signal is under-sampled. The signal is distorted by low frequencies
falsely being reconstructed from an insucient number of sample points.
Figure 5.2 Low Sample Rate
5.4 Bandwidth and Sample Rate
An oscilloscope’s bandwidth is typically described as the lowest frequency at which input signal sine waves are attenuated
by 3 dB (-30% amplitude error).
The sampling theory requires the sample rate to be 𝑓𝑆= 2 ∗ 𝑓𝐵𝑊. However, the theory assumes there are no frequency
components above 𝑓
𝑀𝐴𝑋(𝑓𝐵𝑊
in this case) and it requires a system with an ideal brick-wall frequency response.
Figure 5.3 Brick-Wall Frequency Response
Digital signals have frequency components about the fundamental frequency (Square waves are made up of sine waves at
the fundamental frequency and an innite number of odd harmonics), and typically, for 500 MHz bandwidths and below,
oscilloscopes have a Gaussian frequency response.
Loading...