Time Electronics 5041 User manual

Time Electronics Ltd
Unit 11 Botany Industrial Estate
Tonbridge, Kent, TN9 1RH
Tel: [phone] Fax: [phone]
E-Mail: [email protected]
Web Site: www.TimeElectronics.co.uk
V10.3 16/04/08
5041
Oscilloscope & Timer
Counter Calibrator
Technical Manual

CONTENTS
Chapter 1 - INTRODUCTION.......................................................... 3
Chapter 2 - SPECIFICATION .......................................................... 4
Chapter 3 - SETUP & FRONT PANEL............................................ 5
3.1 Mains Input Voltage
3.2 Communication Settings
3.3 Communication Connections
3.4 GPIB User Commands
3.5 Front Panel
3.6 Output Connections
Chapter 4 - OPERATION ................................................................ 9
4.1 Installing program on PC
4.2 Amplitude Function
4.3 Fast Rise Function (Bandwidth Determination)
4.4 Frequency (Time Base) Function
4.5 Period Function
4.6 2.2 GHz Levelised Sine Function
Chapter 5 - EASYCAL .................................................................... 18
Chapter 6 - FAULT DIAGNOSIS ..................................................... 27
6.1 Mains Power Unit……………………………… 28
Chapter 7 - GUARANTEE & SERVICE FACILITIES ........................ 29
The information contained in this document is subject to change without notice. We make no warranty of any kind
with regard to this material, including, but not limited to, the implied warranties or merchantability and fitness for a
particular purpose. We shall not be liable for errors contained herein or for incidental consequential damages in con-
nection with the furnishing, performance or use of this material.
All trademarks and trade names are recognised.
Windowsis copyright of the Microsoft Corporation.
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Chapter 1 - INTRODUCTION
5041 OSCILLOSCOPE & TIMER/COUNTER CALIBRATOR
The 5041 is a versatile high accuracy calibrator capable of calibrating a wide range of
oscilloscopes and timer/counters to 2.2GHz. It provides a wide range of calibrated
outputs for amplitude, frequency, period and bandwidth.
The 5041 is compatible with Time Electronics’ well established EasyCal software.
The 5041 follows the modern trend of instrumentation which is PC control based and
has few front panel controls and switches. A virtual front panel is displayed on the PC
screen and communication with the unit is via the RS232 (serial) or GPIB (IEEE) port.
The 5041 is supplied as standard with a Windows based control program that is both
user friendly and simple to use. The program will be supported and updated free of
charge for the life of the instrument.
For a greater precision of bandwidth determination and additionally, a frequency
response analysis function, a 10MHz to 2.2GHz levelised sine wave option is
available. The frequency over this range can be swept manually or under the control of
the manual control program or Time Electronics’ EasyCal software. This enables
precision response analysis of and oscilloscopes input amplifiers (and any other high
frequency amplifier). If read-back of the amplifier’s output is available, either via the
serial link or GPIB, a fully closed loop calibration can be done.
For calibration of oscilloscope current probes an optional external battery powered
adapter is available. This converts the 5041’s amplitude output to current and covers
the range 0.1 – 100 mA pk-pk, 0.2% accuracy, DC or 1kHz.
Enhanced timing performance is optionally available by specifying a rubidium atomic
clock module (9762). This option is required to achieve the timing accuracy required to
calibrate high performance Timer/Counters which need accuracies of 1 part in 10 E-10.
By using a GPS frequency standard it is possible to cross check to International
Standards the accuracy of the Rubidium oscillator.
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Chapter 2 SPECIFICATIONS
AMPLITUDE CALIBRATION
FREQUENCY CALIBRATION
GENERAL INFORMATION
Power: 100 - 230V AC (+/-7%) 50 or 60Hz
Dimensions: 43cm wide x 25cm deep x 15cm high (17 x 10 x 6 ins ) 7Kg (15 lbs)
ORDERING INFORMATION Order Code
Scope and Timer/Counter Calibrator for use with external PC 5041
EasyCalSoftware 9747
1GHzsweep 9761
Rubidium frequency reference 9762
Current probe calibration adapter 9764
Rack mount kit (standard 19”) 9728
PCIGPIBboard 9743
Output Levels per Div 1mV to 50V in 1,2,5 sequence, 1kHz square wave or DC.
Graticule Divisions X 1, 2, 4, 6, 8. Max output 200V pk-pk into >500kohm/100pF or 2V into 50ohm
Accuracy 1mV-200mV: 0.2%+/-4uV. >300mV: 0.05%. Into 50ohm: 0.25%+/-4uV. TC<20ppm/C
Low Range 0.1Hz to 170kHz (in steps equivalent to 1µs intervals). Output: 1Vpp into 50ohm
High Range 200, 500kHz, 1, 2, 5,10, 20, 50, 100MHz. Output: 400mVpp into 50ohm
Accuracy 10MHz & below: 0.02ppm, <0.1ppm/yr stab. 20/50/100MHz: 5ppm, <10ppm/yr stab
PERIOD CALIBRATION
Low Frequency Mode 6µs to 15s (settable in 1µs steps). Output: 1V pp into 50ohm (2Vpp into open circuit)
High Frequency Mode 10, 20, 50, 100, 200, 500ns, 1, 2, 5µs. Output: 400mVpp into 50ohm
Accuracy 100ns - 15s: 0.02ppm +/- 30ps, <0.1ppm/yr. 10/20/50 ns: +/- 50ps, <10ppm/yr
MARK/SPACE RATIO
Range 0.01% to 99.99% for periods >20ms. For periods <20ms the % mark/space resolution
is determined by a minimum 2us step. Output level: as Frequency and Period
FAST RISE
Fast Rise Time < 300ps. Allows bandwidth checking up to 1 GHz. Output: 400mVpp into 50ohm.
PROGRAMMABLE OPERATION
Interfaces SERIAL (RS232) and GPIB (IEEE-488)
Commands A full command set allows complete control of all functions by an external computer
SOFTWARE
PC Program An easy-to-use program allows full control of the calibrator from an external PC
PC Requirement PC running Windows 98, ME, 2000, or XP. RS232 serial or GPIB port
EasyCal The 5041 is fully compatible with Time Electronics’ EasyCal software which includes
an in-built driver to allow speedy automatic calibration runs.
1GHz sweep 10MHz - 2.2GHz levelised sine wave output (1Vpp). Precision bandwidth calibration
Rubidium reference Rubidium atomic clock frequency reference. Increases freq/per acc to 1 in 10 E 10
Current probe adapter A battery powered adapter for checking current probes. 0.1-100mA, 0.2% accuracy
OPTIONS

Chapter 3 SETUP & FRONT PANEL
3.1 Mains Input Voltage
The supply power is connected via a standard IEC Euro connector on the rear panel.
The standard voltage supply is 100V - 230V 50/60Hz. There are two protection fuses
mounted in the IEC connector assembly, both are T3.15A slow blow.
3.2 Communication Settings
The 5041 can communicate via GPIB or RS232 (serial) connection. GPIB preferred if
other instruments are to be used on the same bus. Note GPIB operation requires the
PC to be fitted with a GPIB interface card and the relevant software drivers. Time
Electronics option 9743 or equivalent are suitable.
The 5041 hardware communications settings are set using the DIP Switch on the rear
panel. Note: All switches are in the OFF position when set to the left, and ON when set
to the right.
(see rear panel photo on following page).
DIP Switch Use
1 GPIB/RS232 OFF = GPIB ON = RS232
2-6 Binary-coded GPIB address (not used if RS232 is selected)
When the switches are OFF (to the left) they have the value 0
When the switches are ON (to the right), they have the values,
Switch 2 = 1
Switch 3 = 2
Switch 4 = 4
Switch 5 = 8
Switch 6 = 16
The GPIB address is determined by the sum of the switch values.
For example, to set the GPIB address to 20:
Set switch 4 (value 4) and switch 6 (value 16) ON
Set switches 2, 3, and 5 OFF
Address = 0+0+4+0+16 = 20
7-8 Not used – Keep in the OFF position
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Only change the DIP switch settings while the unit is turned off – changes in DIP
switch settings will not be recognized while the unit is on.
3.3 Communication Connections
The 5041 must be connected to the PC by a GPIB cable or a “straight-through”
RS232 cable. Do not connect or disconnect the unit from the PC while the 5041 or
PC is switched on.
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Note that all commands taking parameters must have at least one space after the command
itself before the first parameter. Multiple parameters must be separated by commas, although
spaces are optional.
Standard Function Commands
These are the commands that are used to set the output of the device.
* - Command is valid only in frequency or period mode.
+ - Command is valid only in amplitude mode.
Command Description Example
FUNC? Return the output current function. Will return
either “F”, “P”, “A”, “FR” or “OFF”
FUNC?
F <Hertz> Set the frequency to the value specified in
Hertz (0.1 – 100000000)
F 0.15
F? *Return current frequency setting in Hz F?
P <seconds> Set the period to the value specified in
seconds (0.00000001 – 15)
P 0.5
P? *Return the current period setting in seconds P?
D <%> *Set the duty cycle to the value specified in %
(0.0001 – 99.9999)
D 20.2
D? *Return the current duty cycle setting D?
SWA <mV> Sets the 2.2 GHz Sweep Amplitude (in mV) SWA 1000
SWF <kHz> Sets the 2.2 GHz Sweep Frequency (in kHz) SWF 10000
A <Volts> Set the output voltage to the value specified
in Volts (0.000001 – 20)
A 10.2
A? +Return the current amplitude setting in Volts A?
G
<graticules>
+Set the graticule height to the number
specified (0 – 9)
G 1
G? +Return the current graticule height G?
WAVE DC +Set the wave to DC WAVE DC
WAVE SQ +Set the wave to 1kHz square wave WAVE SQ
WAVE? +Return the current wave setting WAVE?
50R ON +Turn on 50Ohm mode 50R ON
50R OFF +Turn off 50Ohm mode 50R OFF
50R? +Return the 50Ohm mode setting 50R?
FR Switch to fast rise output mode FR
OFF Turn all outputs off OFF
3.4 GPIB User Commands

Other User Commands
Other commands the user may need to use to set-up the unit.
Command Description Example
ERROR? Return the error code of the last error ERROR?
GET ON Enter GET mode GET ON
GET OFF Leave GET mode GET OFF
*TRG GET mode trigger *TRG
TERM 1 Set the transmit terminator to CR TERM 1
TERM 2 Set the transmit terminator to LF TERM 2
TERM 12 Set the transmit terminator to CR+LF TERM 12
TERM 21 Set the transmit terminator to LF+CR TERM 21
TERM 0 Set the transmit terminator nothing TERM 0
*IDN? Return the identity of the unit *IDN?
*RST Perform a full reset of the unit *RST
*TST? Perform a self-test of the unit. Returns an
error code or 0.
*TST?

3.5 Front Panel
The LED indicators on the front panel are, Mains On, Amplitude, GHz Sweep, Time
Markers and Data. The data transfer over the communications link is indicated by the
Data led flashing.
The 16-character alphanumeric display indicates the unit’s current output, e.g. the
output frequency, period, or amplitude. It also shows error messages which are also
indicated by a short beep from the internal buzzer.
LED Meaning
Power The unit is switched on
Data Flashes to indicate data received on the comms port (GPIB or
RS232)
Amplitude When lit, this indicates that there is output from the amplitude
BNC connector.
Time Markers When lit, indicates that there is an output signal from the Time
Markers BNC connector
GHz Sweep
(if fitted)
When lit, indicates that there is an output signal from the GHz
Sweep connector
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3.6 Output Connections
There are 2 (or 3, if the GHz sweep option is fitted) connectors on the front panel of the
5041. From left to right these are:
Amplitude Output
The output from this connector is used to calibrate the amplitude scale of
oscilloscopes. Output can be varied between 1mV and 200V maximum. Output is
either DC or 1kHz square wave.
GHz Sweep Output
This is only present if the 2.2GHz Sweep option is fitted. The output is adjustable from
10MHz up to 2.2GHz. When an output signal is present, the LED above the connector
is lit.
Time Marker
The output from this BNC is used to calibrate the time-base of oscilloscopes, and the
period and frequency readouts of digital oscilloscopes. It is also suitable for calibration
of timer/counters. Duty cycle calibration is also performed using this BNC. When an
output signal is present on this connector, the LED above is lit.
Note:
Good quality, 50 Ohm impedance leads e.g. RG58C/U are recommended for correct
performance at high frequencies. Length is not critical but 1 metre or less is
recommended.
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Chapter 4 OPERATION
4.1 PC Control Program
Installation
1. Insert supplied CD.
2. Locate and run the application “PCControl5041Setup.exe”.
3. Follow the steps guiding you through the setup program.
4. Once completed, the program can be run from the “Time Electronics 5041” entry
in the Start/ Programs list or a desktop Icon.
Program Configuration
Before running the program the hardware configuration should be set as described in
Chapter 3. Once this has been done it is necessary to set-up the program configuration
to match the hardware configuration. To enter the program configuration press the
‘Setup’ function button.
Select either GPIB or RS232 for the desired control mode.
In GPIB mode the GPIB address will need to be set to match that which has been set
on the 5041 (see Chp 3). Note that for GPIB operation the PC must have a GPIB
adapter fitted and the relevant driver software installed.
For RS232 mode only the COM port needs to be selected. Either COM1 or COM2 can
be selected. The baud rate and the other serial communication parameters are fixed
and the program and 5041 firmware are matched.
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4.2 Amplitude Function
To enter the amplitude calibration function, click the “Amplitude” tab at the top of the
window.
Note: It is recommended that when calibrating high frequency (>100MHz) that the
lowest bandwidth setting be used. This is to reduce the amount of spurious pickup noise
that is present on the low mV ranges
To provide an amplitude output, both the range (mV or V/div) and the number of
graticule divisions must be selected. The graticule divisions are designed to match the
number of main divisions found on the majority of scopes. A choice of output types is
available, ‘1 KHz Square’ (a square wave), ‘DC’ (a DC level), or ‘Zero’ (a zero voltage
on the output).
To speed up calibration and get a direct read-out of the % error it is possible to deviate
the output in small increments. Press the Deviation button to enter this mode. The
legend on the button indicates whether or not the unit is in this mode. When Deviation
mode is ON additional buttons appear and allow the output to be incremented or
decremented in 0.01% or 0.1% steps. A ‘0’ button allows the deviation to be
immediately removed. The amount of deviation is shown adjacent to the buttons and is
the direct read-out of the error when the output has been adjusted to give the correct
reading on the scope. Please note that deviation is not available for the maximum
output of 200V DC or square wave
Full information about the output signal is given in the main display window.
The 5041 is capable of driving a 50 ohm termination with 2V DC or pk-pk signals. Note
that the resulting accuracy is reduced - see Chp 2 specification. Also note that the final
accuracy will be further reduced by the accuracy of the 50 ohm termination resistor. For
precision calibration the user should make allowance by consulting the scope
manufacturer’s specification.
Note: Modern oscilloscopes with digital read-outs tend to give poor performance at low
levels (<20mV/div), particularly with wide bandwidths due to the noise that is internally
generated in the scope’s input amplifiers. It should also be noted that most digital
scopes have two ways of displaying the amplitude value of a square wave, the
averaged top and bottom mode should be used since the pk-pk mode will pick up on
any the noise and small spikes on the signal and give an incorrect value. The following
screen pictures show these effects.
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Typical Amplitude outputs:
Tektronix 7A22 1mV/div 1 MHz bandwidth
LeCroy 9314AM digital 100mV/div, 50 ohm terminated, full bandwidth
LeCroy 9314AM digital 2mV/div, 50 ohm terminated, full bandwidth
(notice the internal scope generated noise)
Page 11

4.3 Fast Rise Function (Bandwidth determination)
The fast rise screen provides a means for calculating the approximate bandwidth of a
scope. Selecting this function provides the fast rise-time signal needed for the
determination of a scope’s rise time. The signal is output from the Time Marker’s
connector.
The bandwidth is calculated by first measuring the scopes displayed rise time using the
very fast rising edge of the 5041’s fast-rise signal. The rise time value is then input to
the program and a bandwidth calculated using a mathematical formula. The result is
shown in the main display window.
It is very important with all scopes to use a 50 ohm terminated input. Some scopes,
such as the LeCroy and most of the Tektronix range have the ability to allow the user to
switch in an internal 50 ohm termination. If this is not available, an external 50 ohm
through termination - available from Time Electronics or main line electronics
component distributors.
Set the “flat” portions of the waveform on 0% and
100% and measure the 10% to 90% rise time.
The rise time (in nanosec) should be entered into
the relevant box on the PC window. Clicking on
the ‘Calculate’ button or hitting the “Return” key
will show the approximate bandwidth in the main
display window. Note: The bandwidth calculation
automatically compensates for the 5041 signal
output rise time.
LeCroy 9314AM bandwidth determination: Measured rise time is about 0.8ns (the
scope read-out shows 0.82ns) If 0.8ns is entered into the program calculator a band-
width of 460 MHz is shown, which is approximately correct for this scope.
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4.4 Frequency (Time Base) Function
The 5041 provides frequencies from 0.1Hz to 100MHz in two basic ranges. Low Range
is 0.1Hz to 170kHz , and the High Range is 200kHz to 100MHz. This function is suitable
for calibrating oscilloscope time bases and also timer-counters.
For the Low Range the output is a nominal 1V pk-pk square wave when driving a 50
ohm termination, and a nominal 2V pk-pk when driving high impedance (>10Kohms).
For the High Range the nominal output is 400mV pk-pk into 50 ohms. It is
recommended that only 50 ohm termination be used for this range to prevent waveform
distortion due to ringing and reflections. However, some distortion of the waveform will
not affect the frequency accuracy and output level will be approximately 800mV.
For the Low Range the required frequency is entered via a numeric keypad. After
entering the required value either Hz or kHz should be selected. Due to resolution
considerations not all frequencies are available. For example 10KHz and 8kHz are
available but for 9kHz only 9.009kHz is available.
If an unavailable frequency is selected, the nearest available frequency will
automatically be displayed in a pop-up window and the user will have the option to
accept or reject.
Duty cycle setting:
For all frequencies in the Low Range the duty cycle of the output square wave can be
set. This is done in the same way as frequency setting on the numeric keypad.
However, after entering the value (as a %), the ’% Duty Cycle’ button should be
pressed. As with the frequencies not all values of duty cycle are available, a pop-up
window will show the user the closest duty cycle available and allow accept/reject.
On the High Range (200 kHz to 100 MHz), only fixed frequencies are available. These
are selected using the labelled buttons, shown below.
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Examples of Frequency function outputs:
Example of effect of a poor quality
cable
(Note the distortion effects)
The same conditions with a good
quality cable
Example of a 20% Mark/Space output The 100MHz output displayed on
a Tek 3000
Page 14

4.5 Period Function
The period function mirrors the frequency mode, again having two ranges.
The Short Period Range provides fixed periods from 10ns to 5µs.
The Long Period Range provides periods from 6µs to 15s.
As with frequency the short period range has fixed values and the long period range has
numeric keypad entry. Similarly various periods can not be set and the user is informed
of the nearest available value.
Duty cycle setting is again available on the long period range with the same limitations
on the values that are available.
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4.6 2.2 GHz Levelised Sine Wave Function
This option provides a pure sine-wave of controlled amplitude from 10MHz to 2GHz.
Oscilloscope bandwidths can be accurately determined by sweeping the frequency
up to the 3dB point (approximately a 30% reduction)
For high frequency timer counter calibration the accuracy is determined by an oven
controlled crystal oscillator with an accuracy of 0.02 ppm and 0.1ppm per year stability.
SPECIFICATION:
FREQUENCY
AMPLITUDE (into 50 ohm load)
OPERATION:
This function is selected from the main menu. The output is via the centre connector
on the front panel.
Please note that the 5041’s display is not active for
this function.
The frequency sweep is controlled by three sets of
buttons which increment/decrement in 1, 10,
100MHz steps. Specific frequencies to a resolution
of 0.025 MHz can be entered via the numeric
keypad.
For direct read-out of error, a deviation feature is provided - this allows the frequency
to be deviated up to +/-10% with a 0.001% resolution. Please note that the deviation
setting is limited by the frequency setting resolution of 25KHz. This means that it is
not always possible to achieve the deviation accuracy shown in the display.
Deviation control is only usable above 15MHz.
The amplitude can be adjusted with +/- buttons and reset to the default switch on
value (360mV rms) using the ‘R’ button.
Frequency range 10MHz to 2.2GHz
Frequency resolution 25KHz
Frequency accuracy/stability 0.02 ppm / 0.1ppm per year. Oven controlled crystal
oscillator
10MHz to 2GHz (adjustable) 150mV min - 400 mV max rms (default apprx 360mV)
Above 2GHz not levelised - uncontrolled
Amplitude levelling accuracy
+/- 1% up to 200MHz
+/- 4% 200MHz to 500MHz
+/- 10% 500MHz to 1GHz
+/- 20% 1GHz to 2GHz
Page 16

Oscilloscope Bandwidth and Frequency Response Calibration:
An oscilloscope’s bandwidth and frequency response can be checked using a sine-
wave signal that has an accurately controlled amplitude over a wide range of
frequency. The absolute accuracy of the sine-wave is not important, only its stability
with change in frequency.
For frequency response checking it is usual to set a known output level at the lowest
frequency of interest and increase the frequency in desired steps. The response
(output) of the instrument under test is then recorded at each of the required
frequencies.
For oscilloscopes, the low end frequency amplitude should be set to a convenient
number of graticules using the +/- buttons. The amplitude should then be monitored
as the frequency is increased. The oscilloscopes bandwidth is the frequency at
which the amplitude falls to 70% (3dB down) of the originally set value.
Please note that the output impedance is 50 ohms and the amplitude setting range
is 140 - 400mV rms when driving into 50 ohms. If the output is un-loaded the setting
range is 280 - 800mV.
It is important to ensure at high frequencies (>100MHz) that the output is terminated
into 50 ohms, otherwise ringing and reflections in the connecting cables will cause
errors. For frequencies above 200MHz it is important to use high quality coaxial
cable to prevent erroneous errors occurring.
When calibration digital oscilloscope’s digital display of frequency it is
recommended that the averaging function on the scope be used to ensure a stable
reading.
Above 2GHz the output is available up to 2.2GHz, but the amplitude is no longer
levelised and falls away rapidly. It is therefore not recommended for amplitude
calibration, but is still accurate and suitable for frequency calibration.
Output at 2.2GHz
Page 17

Chapter 5 EasyCal
Using the 5041 in conjunction with EasyCal allows automated oscilloscope and timer/
counter calibration runs to be performed.
Please Note: In order to use EasyCal with the 5041 you must be using EasyCal
version 5.25 or later.
Adding the 5041 to the List of Calibration Instruments
To use the 5041 with EasyCal, first you need to add it to the list of calibration
instruments. To do this:
1) Start EasyEdit
2) Select menu option System Setup
3) Select menu option Calibration Instruments.
The screen will look something like this:
4) Click Add… Another screen will appear. Using the pull-down list in the Type
entry box, select 5041 Scope and Timer/Counter Cal. Enter the GPIB address of the
5041 and other details of the unit. The screen will look something like this:
5) Click OK. The screen will close and return you to the list of calibration
instruments. You will see that the 5041 has been added to the list.
6) Click Exit to close the calibration instruments list. You may now exit EasyEdit in
the normal way.
Page 18