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Service Guide
Publication Number 33120-90017 (order as 33120-90104 manual set) Edition 6, March 2002
© Copyright Agilent Technologies, Inc. 1994-2002 For Safety information, Warranties, and Regulatory information, see the last page in this manual.
Agilent 33120A 15 MHz Function / Arbitrary Waveform Generator
Note: Unless otherwise indicated, this manual applies to all Serial Numbers.
The Agilent Technologies 33120A is a high-performance 15 MHz synthesized function generator with built-in arbitrary waveform capability. Its combination of bench-top and system features makes this function generator a versatile solution for your testing requirements now and in the future.
Convenient bench-top features
10 standard waveforms Built-in 12-bit 40 MSa/s arbitrary waveform capability Easy-to-use knob input Highly visible vacuum-fluorescent display Instrument state storage Portable, ruggedized case with non-skid feet
Flexible system features
Four downloadable 16,000-point arbitrary waveform memories GPIB (IEEE-488) interface and RS-232 interface are standard SCPI (Standard Commands for Programmable Instruments) compatibility Agilent IntuiLink Arb Waveform Generation Software for Microsoft® Windows®
Warning
The procedures in this manual are intended for use by qualified, service-trained personnel only.
Agilent 33120A 15 MHz Function / Arbitrary Waveform Generator
The Front Panel at a Glance
1 2 3 4
Function / Modulation keys Menu operation keys Waveform modify keys Single / Internal Trigger key (Burst and Sweep only)
5 6 7 8
Recall / Store instrument state key Enter Number key Shift / Local key Enter Number "units" keys
2
Front-Panel Number Entry
You can enter numbers from the front-panel using one of three methods.
Use the knob and the arrow keys to modify the displayed number.
Use the arrow keys to edit individual digits.
Increments the flashing digit. Decrements the flashing digit.
Moves the flashing digit to the right. Moves the flashing digit to the left.
Use the "Enter Number" mode to enter a number with the appropriate units.
Use "Enter" for those operations that do not require units to be specified (AM Level, Offset, % Duty, and Store/Recall State).
3
The Front-Panel Menu at a Glance
The menu is organized in a top-down tree structure with three levels.
A: MODulation MENU
1: AM SHAPE
Õ
2: AM SOURCE
Õ
3: FM SHAPE
Õ
4: BURST CNT
Õ
5: BURST RATE
Õ
Õ
6: BURST PHAS
Õ
7: BURST SRC
Õ
8: FSK FREQ
Õ
9: FSK RATE
Õ
10: FSK SRC
B: SWP (Sweep) MENU
1: START F
Õ
2: STOP F
Õ
3: SWP TIME
Õ
4: SWP MODE
C: EDIT MENU*
1: NEW ARB
Õ [ 2: POINTS ] Õ [ 3: LINE EDIT ] Õ [ 4: POINT EDIT ] Õ [ 5: INVERT ] Õ [ 6: SAVE AS ] Õ 7: DELETE
* The commands enclosed in square brackets ( [ ] ) are "hidden" until you make a selection from the
NEW ARB command to initiate a new edit session.
D: SYStem MENU
1: OUT TERM
Õ
2: POWER ON
Õ Õ
3: ERROR
Õ
4: TEST
Õ
5: COMMA
Õ
6: REVISION
E: Input / Output MENU
1: HPIB ADDR
Õ
2: INTERFACE
3: BAUD RATE
Õ
4: PARITY
Õ
5: LANGUAGE
F: CALibration MENU*
1: SECURED or [ 1: UNSECURED ] is UNSECURED for calibration.
Õ
[ 2: CALIBRATE ]
Õ
3: CAL COUNT
Õ
4: MESSAGE
* The commands enclosed in square brackets ( [ ] ) are "hidden" unless the function generator
4
Display Annunciators
Adrs Rmt Trig AM FM Ext FSK Burst Swp
ERROR
Offset Shift Num Arb
Function generator is addressed to listen or talk over a remote interface. Function generator is in remote mode (remote interface). Function generator is waiting for a single trigger or external trigger (Burst, Sweep). AM modulation is enabled. FM modulation is enabled. Function generator is set for an external modulation source (AM, FSK, Burst). FSK (frequency-shift keying) modulation is enabled. Burst modulation is enabled. Sweep mode is enabled. Hardware or remote interface command errors are detected. The waveform is being output with an offset voltage. "Shift" key has been pressed. Press "Shift" again to turn off. "Enter Number" mode is enabled. Press "Shift-Cancel" to disable. Arbitrary waveform function is enabled. Sine waveform function is enabled. Square waveform function is enabled. Triangle waveform function is enabled. Ramp waveform function is enabled.
To review the display annunciators, hold down the Shift key as you turn on the function generator.
5
The Rear Panel at a Glance
1 2 3 4
Chassis ground Power-line fuse-holder assembly Power-line voltage setting AM modulation input terminal
5 External Trigger / FSK / Burst modulation input terminal 6 GPIB (IEEE-488) interface connector 7 RS-232 interface connector
Use the front-panel Input / Output Menu to:
Select the GPIB or RS-232 interface (see chapter 4 in User's Guide). Set the GPIB bus address (see chapter 4 in User's Guide). Set the RS-232 baud rate and parity (see chapter 4 in User's Guide).
6
In This Book
Specifications Chapter 1 lists the function generator's specifications and describes how to interpret these specifications. Quick Start Chapter 2 prepares the function generator for use and helps you get familiar with a few of its front-panel features. Front-Panel Menu Operation Chapter 3 introduces you to the front-panel menu and describes some of the function generator's menu features. Calibration Procedures Chapter 4 provides calibration, verification, and adjustment procedures for the function generator. Theory of Operation Chapter 5 describes block and circuit level theory related to the operation the function generator. Service Chapter 6 provides guidelines for returning your function generator to Agilent for servicing, or for servicing it yourself. Replaceable Parts Chapter 7 contains a detailed parts lists of the function generator. Schematics Chapter 8 contains the function generator's block diagram, schematics, disassembly drawings, and component locator drawings. For information on using the Phase-Lock Option for the 33120A, refer to the User's and Service Guide included with the Option 001.
If you have questions relating to the operation of the 33120A, call 1-800-452-4844 in the United States, or contact your nearest Agilent Technologies Sales Office. If you believe your 33120A has failed, refer to "Operating Checklist", "Types of Service Available", and "Repackaging for Shipment" at the beginning of chapter 6.
7
8
Contents
Chapter 1 Specifications
Chapter 2 Quick Start To prepare the function generator for use 21 If the function generator does not turn on 22 To adjust the carrying handle 24 To set the output frequency 25 To set the output amplitude 26 To set a dc offset voltage 27 To set the duty cycle 28 To output a stored arbitrary waveform 29 To output a dc voltage 30 To store the instrument state 31 To rack mount the function generator 33
Contents
Chapter 3 Front-Panel Menu Operation Front-panel menu reference 37 A front-panel menu tutorial 39 To select the output termination 44 To output a modulated waveform 45 To unsecure the function generator for calibration 47 Chapter 4 Calibration Procedures Agilent Calibration Services 51 Calibration Interval 51 Time Required for Calibration 51 Automating Calibration Procedures 52 Recommended Test Equipment 52 Test Considerations 53 Performance Verification Tests 54 Frequency Verification 56 Function Gain and Linearity Verification 56 DC Function Offset Verification 57 AC Amplitude Verification 57 Amplitude Flatness Verification 60 AM Modulation Depth Verification 61 Optional Performance Verification Tests 62
9
Contents
Chapter 4 Calibration Procedures (continued) Calibration Security Code 64 Calibration Count 66 Calibration Message 66 General Calibration/Adjustment Procedure 67 Aborting a Calibration in Progress 69 Frequency and Burst Rate Adjustment 69 Function Gain and Linearity Adjustment 70 AC Amplitude Adjustment (High-Z) 70 Modulation Adjustment 72 AC Amplitude Adjustment (50W) 73 DC Output Adjustment 76 Duty Cycle Adjustment 77 AC Amplitude Flatness Adjustment 77 Output Amplifier Adjustment (Optional) 80 Error Messages 81
Contents
Chapter 5 Theory of Operation Block Diagram Overview 85 Output Attenuator 86 Output Amplifier 87 AM Modulation 89 Pre-attenuator 90 Square Wave and Sync 90 Filters 92 Waveform DAC/Amplitude Leveling/Waveform RAM 93 Direct Digital Synthesis (DDS ASIC) 95 System DACs 96 Floating Logic 97 Earth-Referenced Logic 98 Power Supplies 98 Display and Keyboard 100
10
Contents
Chapter 6 Service Operating Checklist 103 Types of Service Available 104 Repackaging for Shipment 105 Cleaning 105 Electrostatic Discharge (ESD) Precautions 106 Surface Mount Repair 106 To Replace the Power-Line Fuse 107 To Replace the Output Protection Fuse (F801) 107 Troubleshooting Hints 108 Self-Test Procedures 110 Chapter 7 Replaceable Parts Replaceable Parts 113
Contents
Chapter 8 Schematics 33120A Block Diagram 129 Mechanical Disassembly 130 Floating Logic Schematic 131 Digital Waveform Data Synthesis 132 System DAC Schematic 133 Waveform DAC Schematic 134 Filters Schematic 135 Sync, Square Wave, and Attenuator Schematic 136 Output Amplifier Schematic 137 Output Attenuator Schematic 138 Earth Reference Logic Schematic 139 Power Supplies Schematic 140 Display and Keyboard Schematic 141 33120-66521 Component Locator Diagram 142 33120-66502 Component Locator Diagram 143
11
Contents
12
1
1
Specifications
Chapter 1 Specifications Agilent 33120A Function Generator
WAVEFORMS
Standard Waveforms: Sine, Square, Triangle, Ramp, Noise, DC volts, Sine(x)/x, Negative Ramp, Exponential Rise, Exponential Fall, Cardiac 8 to 16,000 points 12 bits (including sign) 40 MSa / sec Four 16,000-point waveforms
SIGNAL CHARACTERISTICS
Squarewave Rise/Fall Time: Overshoot: Asymmetry: Duty Cycle: Triangle, Ramp, Arb Rise/Fall Time: Linearity: Settling Time: Jitter: < 20 ns < 4% 1% + 5 ns 20% to 80% (to 5 MHz) 40% to 60% (to 15 MHz) 40 ns (typical) < 0.1% of peak output < 250 ns to 0.5% of final value < 25 ns
Arbitrary Waveforms: Waveform Length: Amplitude Resolution: Sample Rate: Non-Volatile Memory:
FREQUENCY CHARACTERISTICS
Sine: Square: Triangle: Ramp: Noise (Gaussian): Arbitrary Waveforms: 8 to 8,192 points: 8,193 to 12,287 points: 12,288 to 16,000 points: Resolution: Accuracy: 100 mHz 15 MHz 100 mHz 15 MHz 100 mHz 100 kHz 100 mHz 100 kHz 10 MHz bandwidth 100 mHz 5 MHz 100 mHz 2.5 MHz 100 mHz 200 kHz 10 mHz or 10 digits 10 ppm in 90 days, 20 ppm in 1 year, 18C 28C < 2 ppm / C < 10 ppm / yr
OUTPUT CHARACTERISTICS (1)
Amplitude (into 50W): (2) Accuracy (at 1 kHz): Flatness < 100 kHz: 100 kHz to 1 MHz: 1 MHz to 15 MHz: 1 MHz to 15 MHz: Offset (into 50W): (3) Accuracy: (4) Output Impedance: Resolution: Output Units: Isolation: Protection: 50 mVpp 10 Vpp 1% of specified output (sine wave relative to 1 kHz) 1% (0.1 dB) 1.5% (0.15 dB) 2% (0.2 dB) Ampl 3Vrms 3.5% (0.3 dB) Ampl < 3Vrms
5 Vpk ac + dc 2% of setting + 2 mV
50 ohms fixed 3 digits, Amplitude and Offset Vpp, Vrms, dBm 42 Vpk maximum to earth Short-circuit protected 15 Vpk overdrive < 1 minute
Temperature Coefficient: Aging:
SINEWAVE SPECTRAL PURITY (into 50W)
Harmonic Distortion DC to 20 kHz: 20 kHz to 100 kHz: 100 kHz to 1 MHz: 1 MHz to 15 MHz: Total Harmonic Distortion DC to 20 kHz: Spurious (non-harmonic) Output (DC to 1 MHz): Output (> 1 MHz): Phase Noise: -70 dBc -60 dBc -45 dBc -35 dBc < 0.04%
(1) Add 1/10th of output amplitude and offset specification per C for operation outside of 18C to 28C range (1-year specification). (2) 100 mVpp 20 Vpp amplitude into open-circuit load.
< -65 dBc < -65 dBc + 6 dB/octave < -55 dBc in a 30 kHz band
(3) Offset 2 X peak-to-peak amplitude. (4) For square wave outputs, add 2% of output amplitude additional error.
14
Chapter 1 Specifications Agilent 33120A Function Generator
1
MODULATION CHARACTERISTICS
AM Modulation Carrier -3 dB Freq: Modulation: Frequency: Depth: Source: FM Modulation Modulation: Frequency: Peak Deviation: Source: Burst Modulation Carrier Frequency: Count: Start Phase: Internal Rate: Gate Source: Trigger Source: FSK Modulation Frequency Range: Internal Rate: Source: 10 MHz (typical) Any internal waveform plus Arb 10 mHz to 20 kHz ( 0.05% to 2.5 kHz, then decreases linearly to 0.4% at upper limit) 0% to 120% Internal / External Any internal waveform plus Arb 10 mHz to 10 kHz ( 0.05% to 600 Hz, then decreases linearly to 0.8% at upper limit) 10 mHz to 15 MHz Internal Only 5 MHz max. 1 to 50,000 cycles, or Infinite -360 to +360 10 mHz to 50 kHz 1% Internal or External Gate (1) Single, External, or Internal Rate 10 mHz to 15 MHz ( 0.05% to 600 Hz, then decreases linearly to 4% at upper limit) 10 mHz to 50 kHz Internal / External (1 MHz max.)
SYSTEM CHARACTERISTICS
Configuration Times (2) Function Change: (3) Frequency Change: (3) Amplitude Change: Offset Change: Select User Arb: Modulation Parameter Change: 80 ms 30 ms 30 ms 10 ms 100 ms < 350 ms
Arb Download Times over GPIB: Arb Length 16,000 points 8,192 points 4,096 points 2,048 points Binary 8 sec 4 sec 2.5 sec 1.5 sec ASCII Integer 81 sec 42 sec 21 sec 11 sec ASCII Real (4) 100 sec 51 sec 26 sec 13 sec
Arb Download Times over RS-232 at 9600 Baud: (5) Arb Length 16,000 points 8,192 points 4,096 points 2,048 points Binary 35 sec 18 sec 10 sec 6 sec ASCII Integer 101 sec 52 sec 27 sec 14 sec ASCII Real (6) 134 sec 69 sec 35 sec 18 sec
FREQUENCY SWEEP
Type: Direction: Start F / Stop F: Time: Source: Linear or Logarithmic Up or Down 10 mHz to 15 MHz 1 ms to 500 sec 0.1% Single, External, or Internal
(1) Trigger source ignored when External Gate is selected. (2) Time to change parameter and output the new signal.
REAR-PANEL INPUTS
External AM Modulation: External Trigger/FSK Burst Gate: (1) Latency: Jitter:
5 Vpk = 100% Modulation 5 kW Input Resistance
(3) Modulation or sweep off. (4) Times for 5-digit and 12-digit numbers. (5) For 4800 baud, multiply the download times by two; For 2400 baud, multiply the download times by four, etc. (6) Time for 5-digit numbers. For 12-digit numbers, multiply the 5-digit numbers by two.
TTL (low true) 1.3 ms 25 ns
15
Chapter 1 Specifications Agilent 33120A Function Generator
GENERAL SPECIFICATIONS
Power Supply: (1) 100V / 120V / 220V / 240V 10% (switch selectable) 50 Hz to 60 Hz 10% and 400 Hz 10%. Automatically sensed at power-on. CAT II 50 VA peak (28 W average) 0C to 55C 80% Relative Humidity to 40C Indoor or sheltered location -40C to 70C Power-off state automatically saved. Three (3) UserConfigurable Stored States, Arbitrary waveforms stored separately. Safety Designed to: EMC: Power-Line Frequency: Vibration and Shock: EN61010, CSA1010, UL-1244 EN61326, 1:1997 + 1A:1998 MIL-T-28800E, Type III, Class 5 (data on file) 30 dBa 1 hour 3 years standard IEEE-488 and RS-232 standard SCPI-1993, IEEE-488.2 User's Guide, Service Guide, Quick Reference Card, IntuiLink Arb software, RS-232 cable, Test Report, and power cord.
Power Installation: Power Consumption: Operating Environment:
Acoustic Noise: Warm-Up Time: Warranty: Remote Interface: Programming Language: Accessories Included:
Storage Environment: State Storage Memory:
Dimensions (W x H x D) Bench Top: Rack Mount: Weight:
254.4 mm x 103.6 mm x 374 mm 212.6 mm x 88.5 mm x 348.3 mm 4 kg (8.8 lbs)
N10149
(1) For 400 Hz operation at 120 Vac, use the 100 Vac line-voltage setting.
16
Chapter 1 Specifications Agilent 33120A Function Generator
1
PRODUCT DIMENSIONS
TOP
All dimensions are shown in millimeters.
17
18
2
2
Quick Start
Quick Start
One of the first things you will want to do with your function generator is to become acquainted with its front panel. We have written the exercises in this chapter to prepare the function generator for use and help you get familiar with some of the front-panel operations. The front panel has two rows of keys to select various functions and operations. Most keys have a shifted function printed in blue above the key. To perform a shifted function, press Shift (the Shift annunciator will turn on). Then, press the key that has the desired label above it. For example, to select the AM (amplitude modulation) function, press Shift AM (the shifted version of the key). If you accidentally press Shift , just press it again to turn off the Shift annunciator. Most keys also have a number printed in green next to the key. To enable the number mode, press Enter Number (the Num annunciator will turn on). Then, press the keys that have the desired numbers printed next to them. For example, to select the number "10", press Enter Number 1 0 (next to the and Recall keys). If you accidentally press Enter Number , just press Shift Cancel to turn off the Num annunciator.
20
Chapter 2 Quick Start To prepare the function generator for use
To prepare the function generator for use
The following steps help you verify that the function generator is ready for use. 1 Check the list of supplied items. Verify that you have received the following items with your function generator. If anything is missing, contact your nearest Agilent Technologies Sales Office. One power cord. One RS-232 serial cable. One User's Guide.
2
á This Service Guide.
One folded Quick Reference card. Certificate of Calibration. Agilent IntuiLink Arb Waveform Generation Software. 2 Connect the power cord and turn on the function generator. If the function generator does not turn on, see chapter 6 for troubleshooting information. The front-panel display will light up while the function generator performs its power-on self-test. The GPIB bus address is displayed. Notice that the function generator powers up in the sine wave function at 1 kHz with an amplitude of 100 mV peak-to-peak (into a 50W termination). To review the power-on display with all annunciators turned on, hold down Shift as you turn on the function generator. 3 Perform a complete self test. The complete self-test performs a more extensive series of tests than those performed at power-on. Hold down Shift as you press the Power switch to turn on the function generator; hold down the key for more than 5 seconds. The self-test will begin when you release the key. If the self-test is successful, "PASS" is displayed on the front panel. If the self-test is not successful, "FAIL" is displayed and the ERROR annunciator turns on. See chapter 6 for instructions on returning the function generator to Agilent for service. 21
Chapter 2 Quick Start If the function generator does not turn on
If the function generator does not turn on
Use the following steps to help solve problems you might experience when turning on the function generator. If you need more help, see chapter 6 for instructions on returning the function generator to Agilent for service. 1 Verify that there is ac power to the function generator. First, verify that the function generator's Power switch is in the "On" position. Also, make sure that the power cord is firmly plugged into to the power module on the rear panel. You should also make sure that the power source you plugged the function generator into is energized. 2 Verify the power-line voltage setting. The line voltage is set to the proper value for your country when the function generator is shipped from the factory. Change the voltage setting if it is not correct. The settings are: 100, 120, 220, or 240 Vac (for 230 Vac operation, use the 220 Vac setting). See the next page if you need to change the line-voltage setting. 3 Verify that the power-line fuse is good. The function generator is shipped from the factory with a 500 mAT fuse installed. This is the correct fuse for all line voltages. See the next page if you need to change the power-line fuse.
To replace the 500 mAT fuse, order Agilent part number 2110-0458.
22
Chapter 2 Quick Start If the function generator does not turn on
1 Remove the power cord. Remove the
fuse-holder assembly from the rear panel.
2 Remove the line-voltage selector from
the assembly.
2
Fuse: 500 mAT (for all line voltages) Part Number: 2110-0458
3 Rotate the line-voltage selector until the
correct voltage appears in the window.
4 Replace the fuse-holder assembly in
the rear panel.
100, 120, 220 (230), or 240 Vac
Verify that the correct line voltage is selected and the power-line fuse is good.
23
Chapter 2 Quick Start To adjust the carrying handle
To adjust the carrying handle
To adjust the position, grasp the handle by the sides and pull outward. Then, rotate the handle to the desired position.
Bench-top viewing positions
Carrying position
24
Chapter 2 Quick Start To set the output frequency
To set the output frequency
At power-on, the function generator outputs a sine wave at 1 kHz with an amplitude of 100 mV peak-to-peak (into a 50W termination). The following steps show you how to change the frequency to 1.2 MHz. 1 Enable the frequency modify mode. The displayed frequency is either the power-on value or the previous frequency selected. When you change functions, the same frequency is used if the present value is valid for the new function. 1.000,000,0 KHz 2 Enter the magnitude of the desired frequency.
1
2
Freq
Enter Number 1 . 2
Notice that the Num annunciator turns on and "ENTER NUM" flashes on the display, indicating that the number mode is enabled. 1.2
To cancel the number mode, press Shift Cancel .
¾
MHz m Vpp
3 Set the units to the desired value. The units are selected using the arrow keys on the right side of the front panel. As soon as you select the units, the function generator outputs the waveform with the displayed frequency. To turn off the flashing digit, move the cursor to the left of the display using the arrow keys. 1.200,000,0 MHz
1
You can also use the knob and arrow keys to enter a number.
25
Chapter 2 Quick Start To set the output amplitude
To set the output amplitude
At power-on, the function generator outputs a sine wave with an amplitude of 100 mV peak-to-peak (into a 50W termination). The following steps show you how to change the amplitude to 50 mVrms. 1 Enable the amplitude modify mode. The displayed amplitude is either the power-on value or the previous amplitude selected. When you change functions, the same amplitude is used if the present value is valid for the new function. 100.0 mVPP
1
Ampl
Enter Number 5 0
2 Enter the magnitude of the desired amplitude.
Notice that the Num annunciator turns on and "ENTER NUM" flashes on the display, indicating that the number mode is enabled. 50
To cancel the number mode, press Shift Cancel . 3 Set the units to the desired value.
kHz m Vrms
Shift
¿
The units are selected using the arrow keys on the right side of the front panel. As soon as you select the units, the function generator outputs the waveform with the displayed amplitude. To turn off the flashing digit, move the cursor to the left of the display using the arrow keys. 50.00 mVRMS
1
You can also use the knob and arrow keys to enter a number.
26
Chapter 2 Quick Start To set a dc offset voltage
To set a dc offset voltage
At power-on, the function generator outputs a sine wave with a dc offset voltage of 0 volts (into a 50W termination). The following steps show you how to change the offset to 1.5 mVdc. 1 Enable the offset modify mode. The displayed offset voltage is either the power-on value or the previous offset selected. When you change functions, the same offset is used if the present value is valid for the new function. +0.000 VDC
1
2
Offset
Enter Number
2 Enter the magnitude of the desired offset.
5
1
.
Notice that the Num annunciator turns on and "ENTER NUM" flashes on the display, indicating that the number mode is enabled. Notice that toggles the displayed value between + and . -1.5
To cancel the number mode, press Shift Cancel . 3 Set the units to the desired value.
kHz m Vrms
Shift
¿
At this point, the function generator outputs the waveform with the displayed offset. Notice that the Offset annunciator turns on, indicating that the waveform is being output with an offset. The annunciator will turn on when the offset is any value other than 0 volts. To turn off the flashing digit, move the cursor to the left of the display using the arrow keys. -01.50 mVDC
1
You can also use the knob and arrow keys to enter a number.
27
Chapter 2 Quick Start To set the duty cycle
To set the duty cycle
Applies only to square waves. At power-on, the duty cycle for square waves is 50%. You can adjust the duty cycle for a square waveform from 20% to 80%, in increments of 1% (for frequencies above 5 MHz, the range is 40% to 60%). The following steps show you how to change the duty cycle to 45%. 1 Select the square wave function. Notice that the annunciator turns on, indicating that the square wave function is enabled.
Shift % Duty
2 Enable the duty cycle modify mode. The displayed duty cycle is either the power-on value or the previous value selected. 50 % DUTY
This message appears on the display for approximately 10 seconds. Repeat this step as needed.
Enter Number 4 5
3 Enter the desired duty cycle.
1
Notice that the Num annunciator turns on and "ENTER NUM" flashes on the display, indicating that the number mode is enabled. 45
To cancel the number mode, press Shift Cancel .
Enter
4 Output the waveform with the displayed duty cycle. 45 % DUTY
1
You can also use the knob and arrow keys to enter a number.
28
Chapter 2 Quick Start To output a stored arbitrary waveform
To output a stored arbitrary waveform
There are five built-in arbitrary waveforms stored in non-volatile memory for your use. You can output these waveforms directly from non-volatile memory. The following steps show you how to output an "exponential rise" waveform from memory. 1 Display the list of arbitrary waveforms. The list contains the five built-in arbitrary waveforms (sinc, negative ramp, exponential rise, exponential fall, and cardiac). The list may also contain up to four user-defined arbitrary waveform names. The first choice on this level is "SINC". SINC
2
Shift
Arb List
This message appears on the display for approximately 10 seconds. Repeat this step as needed.
> >
2 Move across to the EXP_RISE choice. EXP_RISE
1
Enter
3 Select and output the displayed arbitrary waveform. Notice that the Arb annunciator turns on, indicating that the output is an arbitrary waveform. The waveform is output using the present settings for frequency, amplitude, and offset unless you change them. The selected waveform is now assigned to the Arb key. Whenever you press this key, the selected arbitrary waveform is output.
1
You can also use the knob to scroll left or right through the choices in the list.
29
Chapter 2 Quick Start To output a dc voltage
To output a dc voltage
In addition to generating waveforms, you can also output a dc voltage in the range 5 Vdc (into a 50W termination). The following steps show you how to output +155 mVdc. 1 Press the Offset key and hold it down for more than 2 seconds. To enter the dc voltage mode, press the Offset key or any key in the top row of function keys and hold it down for more than 2 seconds. The displayed voltage is either the power-on value or the previous offset voltage selected. DCV +0.000 VDC
1
Enter Number 1 5 5
2 Enter the magnitude of the desired voltage.
Notice that the Num annunciator turns on and "ENTER NUM" flashes on the display, indicating that the number mode is enabled. 155
To cancel the number mode, press Shift Cancel .
Shift
3 Set the units to the desired value.
kHz m Vrms
¿
At this point, the function generator outputs the displayed dc voltage. Notice that the Offset annunciator turns on (all other annunciators are off), indicating that a dc voltage is being output. The annunciator will turn on when the offset is any value other than 0 volts. +155.0 mVDC
1
You can also use the knob and arrow keys to enter a number.
30
Chapter 2 Quick Start To store the instrument state
To store the instrument state
You can store up to three different instrument states in non-volatile memory. This enables you to recall the entire instrument configuration with just a few key presses from the front panel. The following steps show you how to store and recall a state. 1 Set up the function generator to the desired configuration. The state storage feature "remembers" the function, frequency, amplitude, dc offset, duty cycle, as well as any modulation parameters.
Shift Store
2
2 Turn on the state storage mode. Three memory locations (numbered 1, 2, and 3) are available to store instrument configurations. The instrument configuration is stored in non-volatile memory and is remembered when power has been off. STORE 1
This message appears on the display for approximately 10 seconds. Repeat this step as needed.
¾
3 Store the instrument state in memory location "2".
1
Use the up and down arrow keys to select the memory location. STORE 2
To cancel the store operation, press Shift Store again or let the display time-out after 10 seconds.
Enter
4 Save the instrument state. The instrument state is now stored. To recall the stored state, turn to the next page.
1
You can also use the knob or "enter number" mode to enter a memory location.
31
Chapter 2 Quick Start To store the instrument state
To verify that the state was stored properly, you can turn the power off before recalling the state.
Recall
5 Recall the stored instrument state. To recall the stored state, you must use the same memory location used previously to store the state. Use the up and down arrow keys to change the displayed storage location. RECALL 2
To cancel the restore operation, press Recall again. This message appears on the display for approximately 10 seconds. Repeat this step as needed.
Enter
6 Restore the instrument state. The function generator should now be configured in the same state as when you stored the setup on the previous page.
When power is turned off, the function generator automatically stores its state in memory location "0". You can recall the power-down state, but you cannot store the state to location "0" from the front panel. Use the POWER ON ENABLE command in the SYS MENU to automatically recall the power-down state when power is turned on. See chapter 3 for more information on using the front-panel menus.
32
Chapter 2 Quick Start To rack mount the function generator
To rack mount the function generator
You can mount the function generator in a standard 19-inch rack cabinet using one of three optional kits available. Instructions and mounting hardware are included with each rack-mounting kit. Any Agilent System II instrument of the same size can be rack-mounted beside the 33120A Function Generator. Remove the carrying handle, and the front and rear rubber bumpers, before rack-mounting the function generator.
2
To remove the handle, rotate it to the vertical position and pull the ends outward.
Front
Rear (bottom view)
To remove the rubber bumper, stretch a corner and then slide it off.
33
Chapter 2 Quick Start To rack mount the function generator
To rack mount a single instrument, order adapter kit 5063-9240.
To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and flange kit 5063-9212.
To install one or two instruments in a sliding support shelf, order shelf 5063-9255, and slide kit 1494-0015 (for a single instrument, also order filler panel 5002-3999).
34
3
3
Front-Panel Menu Operation
Front-Panel Menu Operation
By now you should be familiar with some of the basic features of the front panel. Chapter 2 shows you how to prepare the function generator for use and describes a few of the front-panel features. If you are not familiar with this information, we recommend that you read chapter 2, "Quick Start," starting on page 19. Chapter 3 introduces you to the use of the front-panel menu. This chapter does not give a detailed description of every front-panel key or menu operation. It does, however, give you an overview of front-panel menu operations related to verification, adjustment and service. See chapter 3 "Features and Functions" in the User's Guide for a complete discussion of the function generator's capabilities and operation.
If you purchased the Phase-Lock Option for the 33120A, an additional menu (G: PHASE MENU) is available from the front panel. For information on using the Phase-Lock Option, refer to the User's and Service Guide included with Option 001.
36
Chapter 3 Front-Panel Menu Operation Front-panel menu reference
Front-panel menu reference
A: MODulation MENU
1: AM SHAPE
Õ 2: AM SOURCE Õ 3: FM SHAPE Õ 4: BURST CNT Õ 5: BURST RATE Õ
Õ 6: BURST PHAS Õ 7: BURST SRC Õ 8: FSK FREQ Õ 9: FSK RATE Õ 10: FSK SRC
1: AM SHAPE 2: AM SOURCE 3: FM SHAPE 4: BURST CNT 5: BURST RATE 6: BURST PHAS 7: BURST SRQ 8: FSK FREQ 9: FSK RATE 10: FSK SRC Selects the shape of the AM modulating waveform. Enables or disables the internal AM modulating source. Selects the shape of the FM modulating waveform. Sets the number of cycles per burst (1 to 50,000 cycles). Sets the burst rate in Hz for an internal burst source. Sets the starting phase angle of a burst (-360 to +360 degrees). Selects an internal or external gate source for burst modulation. Sets the FSK "hop" frequency. Selects the internal FSK rate between the carrier and FSK frequency. Selects an internal or external source for the FSK rate.
3
B: SWP (Sweep) MENU
1: START F
Õ 2: STOP F Õ 3: SWP TIME Õ 4: SWP MODE
1: START F 2: STOP F 3: SWP TIME 4: SWP MODE Sets the start frequency in Hz for sweeping. Sets the stop frequency in Hz for sweeping. Sets the repetition rate in seconds for sweeping. Selects linear or logarithmic sweeping.
C: EDIT MENU *
1: NEW ARB
Õ 2: POINTS Õ [3: LINE EDIT] Õ [4: POINT EDIT] Õ [5: INVERT] Õ [6: SAVE AS] Õ 7:DELETE
1: NEW ARB 2: POINTS 3: LINE EDIT 4: POINT EDIT 5: INVERT 6: SAVE AS 7: DELETE Initiates a new arb waveform or loads the selected arb waveform. Sets the number of points in a new arb waveform (8 to 16,000 points). Performs a linear interpolation between two points in the arb waveform. Edits the individual points of the selected arb waveform. Inverts the selected arb waveform by changing the sign of each point. Saves the current arb waveform in non-volatile memory. Deletes the selected arb waveform from non-volatile memory.
* The commands enclosed in square brackets ( [ ] ) are "hidden" until you make a selection from the NEW ARB command to initiate a new edit session.
37
Chapter 3 Front-Panel Menu Operation Front-panel menu reference
D: SYStem MENU
1: OUT TERM
Õ 2: POWER ON Õ 3: ERROR Õ 4: TEST Õ 5: COMMA Õ 6:REVISION
1: OUT TERM 2: POWER ON 3: ERROR 4: TEST 5: COMMA 6: REVISION Selects the output termination (50W or high impedance). Enables or disables automatic power-up in power-down state "0". Retrieves errors from the error queue (up to 20 errors). Performs a complete self-test. Enables or disables a comma separator between digits on the display. Displays the function generator's firmware revision codes.
E: Input / Output MENU
1: HPIB ADDR
Õ 2: INTERFACE Õ 3: BAUD RATE Õ 4: PARITY Õ 5: LANGUAGE
1: HPIB ADDR 2: INTERFACE 3: BAUD RATE 4: PARITY 5: LANGUAGE Sets the GPIB bus address (0 to 30). Selects the GPIB or RS-232 interface. Selects the baud rate for RS-232 operation. Selects even, odd, or no parity for RS-232 operation. Verifies the interface language: SCPI.
F: CALibration MENU *
1: SECURED
Õ [1: UNSECURED] Õ [2: CALIBRATE] Õ 3: CAL COUNT Õ 4: MESSAGE
1: SECURED 1: UNSECURED 2: CALIBRATE 3: CAL COUNT 4: MESSAGE The function generator is secured against calibration; enter code to unsecure. The function generator is unsecured for calibration; enter code to secure. Performs individual calibrations; must be UNSECURED. Reads the total number of times the function generator has been calibrated. Reads the calibration string (up to 11 characters) entered from remote.
* The commands enclosed in square brackets ( [ ] ) are "hidden" unless the function generator is UNSECURED for calibration.
38
Chapter 3 Front-Panel Menu Operation A front-panel menu tutorial
A front-panel menu tutorial
This section is a step-by-step tutorial which shows you how to use the front-panel menu. We recommend that you spend a few minutes with this tutorial to get comfortable with the structure and operation of the menu before attempting verification, calibration, or adjustments. The menu is organized in a top-down tree structure with three levels (menus, commands, and parameters). You move down ¿ or up ¾ the menu tree to get from one level to the next. Each of the three levels has several horizontal choices which you can view by moving left < or right > .
3
Menus Commands Parameters
The menu is organized in a top-down tree structure with three levels.
To turn on the menu, press Shift To turn off the menu, press Shift
Menu On/Off . Menu On/Off .
To execute a menu command, press Enter . To recall the last menu command that was executed, press Shift Recall Menu . To turn off the menu at any time without saving changes, press Shift Cancel .
39
Chapter 3 Front-Panel Menu Operation A front-panel menu tutorial
Messages Displayed During Menu Use
TOP OF MENU You pressed ¾ while on the "MENUS" level; this is the top level of the menu and you cannot go any higher. To turn off the menu, press Shift Menu On/Off . To move across the choices on a level, press < or > . To move down a level, press ¿ . MENUS You are on the "MENUS" level. Press
< or >
to view the choices.
COMMANDS You are on the "COMMANDS" level. Press < or > to view the command choices within the selected menu group. PARAMETER You are on the "PARAMETER" level. Press < or > to view and edit the parameter for the selected command. MENU BOTTOM You pressed ¿ while on the "PARAMETER" level; this is the bottom level of the menu and you cannot go any lower. To turn off the menu, press Shift Menu On/Off . To move up a level, press ¾ . ENTERED The change made on the "PARAMETER" level is saved. This is displayed after you press Enter (Menu Enter) to execute the command. MIN VALUE The value you specified on the "PARAMETER" level is too small for the selected command. The minimum value allowed is displayed for you to edit. MAX VALUE The value you specified on the "PARAMETER" level is too large for the selected command. The maximum value allowed is displayed for you to edit. EXITING You will see this message if you turn off the menu by pressing
Shift Menu On/Off or Shift Cancel . You did not edit any values on the
"PARAMETER" level and changes were NOT saved. NOT ENTERED You will see this message if you turn off the menu by pressing
Shift Menu On/Off or Shift Cancel . You did some editing of parameters but the changes were NOT saved. Press Enter (Menu Enter) to save changes
made on the "PARAMETER" level.
40
Chapter 3 Front-Panel Menu Operation A front-panel menu tutorial
Menu Example 1
The following steps show you how to turn on the menu, move up and down between levels, move across the choices on each level, and turn off the menu. In this example, you will restore the function generator to the power-on default state. This procedure is recommended before performing the verification procedures in chapter 4. 1 Turn on the menu. You enter the menu on the "MENUS" level. The MOD MENU is your first choice on this level. A: MOD MENU 2 Move across to the SYS MENU choice on this level.
1
Shift Menu On/Off
3
>
>
>
There are six menu group choices available on the "MENUS" level. Each choice has a letter prefix for easy identification (A: , B: , etc.). D: SYS MENU 3 Move down to the "COMMANDS" level within the SYS MENU. The OUT TERM command is your first choice on this level. 1: OUT TERM 4 Move across to the POWER ON command on this level.
1
¿
>
There are six command choices available in the SYS MENU. Each choice on this level has a number prefix for easy identification (1: , 2: , etc.). 2: POWER ON
1
You can also use the knob to scroll left or right through the choices on each level of the menu.
41
Chapter 3 Front-Panel Menu Operation A front-panel menu tutorial
¿
5 Move down a level to the "PARAMETER" choices. The first parameter choice is "DEFAULT" for the POWER ON command ("DEFAULT" is the factory setting and is stored in non-volatile memory). DEFAULT 6 Move across to the "LAST STATE" choice. There are two parameter choices for POWER ON. LAST STATE 7 Save the change and turn off the menu. The function generator beeps and displays a message to show that the change is now in effect. You are then exited from the menu. ENTERED
1
>
Enter
8 Cycle the power to restore the default values. Turn the function generator OFF and then ON. The default output state will now be in effect (1 kHz sine wave, 100 mV peak-to-peak, 50W termination).
1
You can also use the knob to scroll left or right through the choices on each level of the menu.
42
Chapter 3 Front-Panel Menu Operation A front-panel menu tutorial
Menu Example 2
Some commands in the menu require that you enter a numeric parameter value. The following steps show you how to enter a number in the menu. For this example, you will change the output amplitude. 1 Select amplitude adjustment The function generator displays the current output amplitude. 100.0 mVPP
Ampl
3
<
2 Move the flashing cursor over to edit the first digit. The cursor movement wraps around. 100.0 mVPP
1
^
^
^
3 Increment the first digit until 300.0 mVPP is displayed. The output amplitude of the function changes as you adjust the displayed value. 300.0 mVPP
1
You can also use the knob and arrow keys to enter a number.
43
Chapter 3 Front-Panel Menu Operation To select the output termination
To select the output termination
The function generator has a fixed output impedance of 50 ohms on the OUTPUT terminal. You can specify whether you are terminating the output into a 50W load or an open circuit. Incorrect impedance matching between the source and load will result in an output amplitude or dc offset which does not match the specified value. 1 Turn on the menu. A: MOD MENU 2 Move across to the SYS MENU choice on this level. D: SYS MENU 3 Move down a level to the OUT TERM command. 1: OUT TERM 4 Move down a level and then across to the HIGH Z choice. With the output termination set to "HIGH Z", the function generator allows you to set the unloaded (open circuit) output voltage. HIGH Z 5 Save the change and turn off the menu. The function generator beeps and displays a message to show that the change is now in effect. You are then exited from the menu.
1 1
Shift
Menu On/Off
>
>
>
¿
¿
>
Enter
1
You can also use the knob to scroll left or right through the choices on each level of the menu.
44
Chapter 3 Front-Panel Menu Operation To output a modulated waveform
To output a modulated waveform
A modulated waveform consists of a carrier and a modulating waveform. In AM (amplitude modulation), the amplitude of the carrier is varied by the amplitude of the modulating waveform. For this example, you will output an AM waveform with 80% modulation depth. The carrier will be a 5 kHz sine wave and the modulating waveform will be a 200 Hz sine wave.
3
1 Select the function, frequency, and amplitude of the carrier. For the carrier waveform, you can select a sine, square, triangle, ramp, or arbitrary waveform. For this example, select a 5 kHz sine wave with an amplitude of 5 Vpp.
Shift AM
2 Select AM. Notice that the AM annunciator turns on.
Shift < Recall Menu
3 Use the menu to select the shape of the modulating waveform. After you enable the AM function, the "recall menu" key will automatically take you to the AM SHAPE command in the MOD MENU. 1: AM SHAPE
45
Chapter 3 Front-Panel Menu Operation To output a modulated waveform
¿
4 Move down a level verify that "SINE" is selected. For the modulating waveform, you can select a sine, square, triangle, ramp, noise, or arbitrary waveform. For this example, you will modulate the carrier with a sine waveform. Notice that the AM annunciator flashes, indicating that the displayed parameter is for AM. SINE 5 Save the change and turn off the menu. The modulating waveform is now a sine waveform. ENTERED 6 Set the modulating frequency to 200 Hz. Notice that the AM annunciator flashes, indicating that the displayed frequency is the modulating frequency. Also notice that the modulating frequency is displayed with fewer digits than the carrier frequency. MOD 200.0 Hz
Enter
Shift
Freq
This message appears on the display for approximately 10 seconds. Repeat this step as needed.
Shift Level
7 Set the modulation depth to 80%. Notice that the AM annunciator flashes, indicating that the displayed percentage is the AM depth (also called percent modulation). 080 % DEPTH
This message appears on the display for approximately 10 seconds. Repeat this step as needed. At this point, the function generator outputs the AM waveform with the specified modulation parameters. 46
Chapter 3 Front-Panel Menu Operation To unsecure the function generator for calibration
To unsecure the function generator for calibration
The function generator can use a calibration security code to prevent unauthorized or accidental calibration. This procedure shows you how to unsecure the function generator for calibration. 1 Turn on the menu. A: MOD MENU 2 Move across to the CAL MENU choice on this level. F: CAL MENU 3 Move down a level to the SECURED command. 1: SECURED
Shift
Menu On/Off
3
<
¿
If the display shows UNSECURED, you do not need to perform this procedure to execute a calibration.
47
Chapter 3 Front-Panel Menu Operation To unsecure the function generator for calibration
¿
4 Move down to the "parameters" level. ^000000:CODE
0 1
3 2
3 0
5 Unsecure the function generator by entering the security code. ^033120:CODE
ENTER
The security code is set to "HP33120" when the function generator is shipped from the factory. The security code is stored in non-volatile memory and does not change when the power has been off or after a remote interface reset. To enter the security code from the front panel, enter only the six digits. To enter the security code from the remote interface, you may enter up to 12 characters. Use the knob or arrow keys to move left or right between digits. Use the up or down arrow keys to change the digits.
To re-secure the function generator following a calibration, perform this procedure again. Additional information about the calibration security feature is given on page 64.
48
4
4
Calibration Procedures
Calibration Procedures
This chapter contains procedures for verification of the function generator's performance and adjustment (calibration). The chapter is divided into the following sections:
Agilent Calibration Services . . . . . . . . . . . . . . 51 Calibration Interval . . . . . . . . . . . . . . . . . . . 51 Time Required for Calibration . . . . . . . . . . . . . 51 Automating Calibration Procedures . . . . . . . . . . 52 Recommended Test Equipment . . . . . . . . . . . . . 52 Test Considerations . . . . . . . . . . . . . . . . . . . 53 Performance Verification Tests . . . . . . . . . . . . . 54 Frequency Verification . . . . . . . . . . . . . . . . . 56 Function Gain and Linearity Verification . . . . . . . 56 DC Function Offset Verification . . . . . . . . . . . . 57 AC Amplitude Verification . . . . . . . . . . . . . . . 57 Amplitude Flatness Verification . . . . . . . . . . . . 60 AM Modulation Depth Verification . . . . . . . . . . . 61 Optional Performance Verification Tests . . . . . . . . 62 Calibration Security Code . . . . . . . . . . . . . . . . 64 Calibration Count . . . . . . . . . . . . . . . . . . . . 66 Calibration Message . . . . . . . . . . . . . . . . . . . 66 General Calibration/Adjustment Procedure . . . . . . 67 Aborting a Calibration in Progress . . . . . . . . . . . 69 Frequency and Burst Rate Adjustment
. . . . . . . . 69
Function Gain and Linearity Adjustment . . . . . . . 70 AC Amplitude Adjustment (High-Z) . . . . . . . . . . 70 Modulation Adjustment . . . . . . . . . . . . . . . . . 72 AC Amplitude Adjustment (50W) . . . . . . . . . . . . 73 DC Output Adjustment . . . . . . . . . . . . . . . . . 76 Duty Cycle Adjustment . . . . . . . . . . . . . . . . . 77 AC Amplitude Flatness Adjustment . . . . . . . . . . 77 Output Amplifier Adjustment (Optional)
. . . . . . . 80
Error Messages . . . . . . . . . . . . . . . . . . . . . 81
50
Chapter 4 Calibration Procedures Agilent Calibration Services
Closed-Case Electronic Calibration The function generator features closed-case electronic calibration since no internal mechanical adjustments are required for normal calibration. The function generator calculates correction factors based upon the input reference value you set. The new correction factors are stored in non-volatile memory until the next calibration adjustment is performed (non-volatile memory does not change when power has been off or after a remote interface reset).
Agilent Calibration Services
When your function generator is due for calibration, contact your local Agilent Service Center for a low-cost recalibration. The 33120A Function Generator is supported on automated calibration systems which allow Agilent to provide this service at competitive prices. Calibrations to MIL-STD-45662 are also available at competitive prices.
4
Calibration Interval
The function generator should be calibrated on a regular interval determined by the measurement accuracy requirements of your application. A 1- or 2-year interval is adequate for most applications. Agilent does not recommend extending calibration intervals beyond two years for any application. Whatever calibration interval you select, Agilent recommends that complete re-adjustment should always be performed at the calibration interval. This will increase your confidence that the 33120A will remain within specification for the next calibration interval. This criteria for re-adjustment provides the best long-term stability. Performance data measured using this method can be used to extend future calibration intervals.
Time Required for Calibration
The 33120A can be automatically calibrated under computer control. With computer control you can perform the complete calibration procedure and performance verification tests in less than 15 minutes. Manual calibrations using the recommended test equipment will take approximately 45 minutes.
51
Chapter 4 Calibration Procedures Automating Calibration Procedures
Automating Calibration Procedures
You can automate the complete verification and adjustment procedures outlined in this chapter if you have access to programmable test equipment. You can program the instrument configurations specified for each test over the remote interface. You can then enter readback verification data into a test program and compare the results to the appropriate test limit values. You can also enter calibration constants from the remote interface. Remote operation is similar to the local front-panel procedure. You can use a computer to perform the adjustment by first selecting the required setup. The calibration value is sent to the function generator and then the calibration is initiated over the remote interface. The function generator must be unsecured prior to initiating the calibration procedure. For further detailing on programming the function generator, see chapters 3 and 4 in the Agilent 33120A User's Guide.
Recommended Test Equipment
The test equipment recommended for the performance verification and adjustment procedures is listed below. If the exact instrument is not available, use the accuracy requirements shown to select substitute calibration standards.
Instrument 50 W feedthrough load 6 1/2 digit Digital Multimeter (DMM) Thermal Voltage Converter (50 W termination type) or Power Meter or Wideband ACrms Meter Frequency Meter Oscilloscope Spectrum Analyzer
*
Requirements 50 W 0.1 W 20 Vdc 0.01% Integrating ACrms 10 Vacrms 0.1% 1kHz to 15 MHz 100 kHz to 15 MHz 1 VAC rms 0.5% 1 kHz to 20 MHz 1 ppm accuracy 100 MHz Response to 90 MHz
Recommended Model
Use* Q,P,O,T
Agilent 34401A 3 Volt Agilent E4418A with Agilent 8482A and 20 dB attenuator -- Agilent 53131A Agilent 54624A Agilent 8560EC
Q,P,T
Q,P
Q,P,T T O
Q = Quick Verification P = Performance Verification Tests
O= Optional Verification Tests T = Troubleshooting
52
Chapter 4 Calibration Procedures Test Considerations
Test Considerations
To ensure proper instrument operation, verify that you have selected the correct power line voltage prior to attempting any test procedure in this chapter. See page 22 in chapter 2 for more information. For optimum performance, all test procedures should comply with the following recommendations:
Verify the function generator is set to the default power on state (power on default). A procedure is given on page 41. Make sure that the calibration ambient temperature is stable and between 18 C and 28 C. Make sure ambient relative humidity is less than 80%. Allow a 1-hour warm-up period before verification or adjustment. Use only RG-58 or equivalent 50W cable. Keep cables as short as possible, consistent with the impedance requirements.
4
53
Chapter 4 Calibration Procedures Performance Verification Tests
Performance Verification Tests
The performance verification tests use the function generator's specifications listed in chapter 1, "Specifications," starting on page 13. You can perform four different levels of performance verification tests:
Self-Test A series of internal verification tests that give a high confidence that the function generator is operational.
Q
Quick Verification A combination of the internal self-tests and selected verification tests. Performance Verification Tests An extensive set of tests that are recommended as an acceptance test when you first receive the function generator or after performing adjustments. Optional Verification Tests Tests not performed with every calibration. These tests can can be used to verify additional instrument specifications following repairs to specific circuits.
P
O
Self-Test
A brief power-on self-test occurs automatically whenever you turn on the function generator. This limited test assures that the function generator is capable of operation. To perform a complete self-test hold down the Shift key as you press the Power switch to turn on the function generator; hold down the key for more than 5 seconds (a complete description of these tests can be found in chapter 6). The function generator will automatically perform the complete self-test procedure when you release the key. The self-test will complete in approximately 5 seconds. You can perform many tests individually (or all tests at once) using the
TEST command in the SYS MENU. You can also perform a self-test from
the remote interface (see chapter 3 in the Agilent 33120A User's Guide).
If the self-test is successful, "PASS" is displayed on the front panel. If the self-test fails, "FAIL" is displayed and the ERROR annunciator turns on. If repair is required, see chapter 6, "Service," for further details. If all tests pass, you have a high confidence (90%) that the function generator is operational.
54
Chapter 4 Calibration Procedures Performance Verification Tests
Quick Performance Check
The quick performance check is a combination of internal self-test and an abbreviated performance test (specified by the letter Q in the performance verification tests). This test provides a simple method to achieve high confidence in the function generator's ability to functionally operate and meet specifications. These tests represent the absolute minimum set of performance checks recommended following any service activity. Auditing the function generator's performance for the quick check points (designated by a Q) verifies performance for "normal" accuracy drift mechanisms. This test does not check for abnormal component failures. To perform the quick performance check, do the following:
Set the function generator to the default power on state (power on default). A procedure is given on page 41. Perform a complete self-test. A procedure is given on page 21. Perform only the performance verification tests indicated with the letter Q.
If the function generator fails the quick performance check, adjustment or repair is required.
4
Performance Verification Tests
The performance verification tests are recommended as acceptance tests when you first receive the function generator. The acceptance test results should be compared against the 1 year test limits. After acceptance, you should repeat the performance verification tests at every calibration interval. If the function generator fails performance verification, adjustment or repair is required.
55
Chapter 4 Calibration Procedures Frequency Verification
Frequency Verification
This test verifies the frequency accuracy of the two sources in the function generator. All output frequencies are derived from a single generated frequency, and only one frequency point is checked. The second test verifies the burst rate frequency. Set the function generator for each output indicated in the table below. Use a frequency meter to measure the output frequency. Compare the measured results to the test limits shown in the table. This is a 50W output termination test.
Agilent 33120A Function Q Q Sine wave Square wave OUT 1 TERM 50 W 50 W Ampl Freq BURST BURST RATE CNT -- -- Measurement Nominal 1.00 kHz 500 Hz Error 0.02 Hz 5 Hz
3.5 Vrms 1.00 kHz
3.5 Vrms 1.00 kHz 500 Hz 1 CYC
Function Gain and Linearity Verification
This test verifies the output amplitude accuracy specification for sine wave, triangle wave, ramp, and square wave outputs. Set the function generator for each output indicated in the table below. Use a DMM to measure the function generator ACrms output voltage. Compare the measured results to the test limits shown in the table. This is a HIGH Z output termination test.
Agilent 33120A Function Q Sine wave Sine wave Triangle wave Ramp wave Q Square wave Square wave OUT TERM HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z
1
Measurement Freq 1.0 kHz 1.0 kHz 100 Hz 100 Hz 100 Hz 100 Hz Nominal 7.0 Vrms 5.7 Vrms 5.7 Vrms 5.7 Vrms 10.0 Vrms 8.0 Vrms Error 0.07 Vrms 0.057 Vrms 0.057 Vrms 0.057 Vrms 0.1 Vrms 0.08 Vrms
Ampl 7.0 Vrms 5.7 Vrms 5.7 Vrms 5.7 Vrms 10.0 Vrms 8.0 Vrms
1
Output termination set using front panel controls. HIGH Z assumes no load on output. 50W assumes a 50W 0.1W load on output.
56
Chapter 4 Calibration Procedures DC Function Offset Verification
DC Function Offset Verification
This test verifies the DC offset and DC output specifications. Set the function generator for each output indicated in the table below. Use a DMM to measure the function generator dcV output. Compare the measured results to the test limits shown in the table. This is a HIGH Z output termination test.
Agilent 33120A Function Q DC Volts DC Volts OUT TERM HIGH Z HIGH Z
1
Measurement Ampl 10.0 Vdc -10.0 Vdc Nominal 10.0 Vdc -10.0 Vdc Error 0.20 Vdc 0.20 Vdc
AC Amplitude Verification
This procedure is used to check the output amplitude calibration of the function generator. Verification checks are performed to check the accuracy of the pre-attenuator and post attenuator. Make sure you have read "Test Considerations" on page 53. Set the function generator for each output indicated in the table on the next page. Use a DMM to measure the ACrms output voltage of the function generator. Compare the measured results to the test limits shown in the table. This is a HIGH Z output termination test.
4
1
Output termination set using front panel controls. HIGH Z assumes no load on output. 50W assumes a 50W 0.1W load on output.
57
Chapter 4 Calibration Procedures AC Amplitude Verification
Agilent 33120A Function Q Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Q Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Q Sine wave Sine wave Sine wave Sine wave Q Sine wave OUT TERM HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z HIGH Z
1
Measurement Freq 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz 1.00 kHz Nominal 7.0 Vrms 5.7 Vrms 5.5 Vrms 4.4 Vrms 3.5 Vrms 2.8 Vrms 2.2 Vrms 1.7 Vrms 1.4Vrms 1.1 Vrms 0.88 Vrms 0.70 Vrms 0.55 Vrms 0.44 Vrms 0.35 Vrms 0.28 Vrms 0.22 Vrms 0.17 Vrms 0.14 Vrms 0.11 Vrms 0.088Vrms 0.070 Vrms 0.055 Vrms 0.044 Vrms 0.036 Vrms Error 0.070 Vrms 0.057 Vrms 0.055 Vrms 0.044 Vrms 0.035 Vrms 0.028 Vrms 0.022 Vrms 0.017 Vrms 0.014 Vrms 0.011 Vrms 0.0088 Vrms 0.0070 Vrms 0.0055 Vrms 0.0044 Vrms 0.0035 Vrms 0.0028 Vrms 0.0022 Vrms 0.0017 Vrms 0.0014 Vrms 0.0011 Vrms 0.00088 Vrms 0.00070 Vrms 0.00055 Vrms 0.00044 Vrms 0.00036 Vrms
Ampl 7.0 Vrms 5.7 Vrms 5.5 Vrms 4.4 Vrms 3.5 Vrms 2.8 Vrms 2.2 Vrms 1.7 Vrms 1.4 Vrms 1.1 Vrms 0.88 Vrms 0.70 Vrms 0.55 Vrms 0.44 Vrms 0.35 Vrms 0.28 Vrms 0.22 Vrms 0.17 Vrms 0.14 Vrms 0.11 Vrms 0.088 Vrms 0.070 Vrms 0.055 Vrms 0.044 Vrms 0.036 Vrms
1
Output termination set using front panel controls. HIGH Z assumes no load on output. 50W assumes a 50W 0.1W load on output.
58
Chapter 4 Calibration Procedures AC Amplitude Verification
Install the 50W feedthrough load between the DMM and the function generator output. Set the function generator for each output indicated in the table on the next page. Use a DMM to measure the ACrms output voltage of the function generator. Compare the measured results to the test limits shown in the table. This is a 50W output termination test.
Agilent 33120A Function Q Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Q Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Q Sine wave Sine wave Sine wave Sine wave OUT TERM 1 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W Ampl 3.5 Vrms 2.8 Vrms 2.2 Vrms 1.7 Vrms 1.4Vrms 1.1 Vrms 0.88 Vrms 0.70 Vrms 0.55 Vrms 0.44 Vrms 0.35 Vrms 0.28 Vrms 0.22 Vrms 0.17 Vrms 0.14 Vrms 0.11 Vrms 0.088Vrms 0.070 Vrms 0.055 Vrms 0.044 Vrms 0.035 Vrms 0.028 Vrms 0.022 Vrms 0.018 Vrms Freq 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz 1.0000 kHz Measurement Nominal 3.5 Vrms 2.8 Vrms 2.2 Vrms 1.7 Vrms 1.4Vrms 1.1 Vrms 0.88 Vrms 0.70 Vrms 0.55 Vrms 0.44 Vrms 0.35 Vrms 0.28 Vrms 0.22 Vrms 0.17 Vrms 0.14 Vrms 0.11 Vrms 0.088Vrms 0.070 Vrms 0.055 Vrms 0.044 Vrms 0.035 Vrms 0.028 Vrms 0.022 Vrms 0.018 Vrms Error 0.035 Vrms 0.028 Vrms 0.022 Vrms 0.017 Vrms 0.014 Vrms 0.011 Vrms 0.0088 Vrms 0.0070 Vrms 0.0055 Vrms 0.0044 Vrms 0.0035 Vrms 0.0028 Vrms 0.0022 Vrms 0.0017 Vrms 0.0014 Vrms 0.0011 Vrms 0.00088 Vrms 0.00070 Vrms 0.00055 Vrms 0.00044 Vrms 0.00035 Vrms 0.00028 Vrms 0.00022 Vrms 0.00018 Vrms
4
1
Output termination set using front panel controls. HIGH Z assumes no load on output. 50W assumes a 50W 0.1W load on output.
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Chapter 4 Calibration Procedures Amplitude Flatness Verification
Amplitude Flatness Verification
This test verifies the output amplitude flatness specification at selected frequencies. If you use a TVC (recommended) or a wide band ACrms voltmeter (with a 50W feed through load), perform this procedure as described. If you are using a measurement device that requires a transfer measurement (for example, a power meter), make the transfer in the reference measurement at 100 kHz. Set the function generator to the first output indicated in the table below and make a reference measurement. Select each function generator output in the table below and adjust the function generator output amplitude until the measured output is at the reference measurement. Compare the amplitude level set on the front panel to the test limits shown in the table. This test is a 50W output termination test.
Agilent 33120A Function Q Sine wave Sine wave Sine wave Q Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Sine wave Q Sine wave OUT TERM 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W 50 W
1
Measurement Freq 1.00 kHz 100.00 kHz 500.00 kHz 1.00 MHz 3.00 MHz 5.00 MHz 7.00 MHz 9.00 MHz 11.00 MHz 13.00 MHz 15.00 MHz Nominal 0.03 Vrms 0.045 Vrms 0.045 Vrms 0.06 Vrms 0.06 Vrms 0.06 Vrms 0.06 Vrms 0.06 Vrms 0.06 Vrms 0.06 Vrms Error
Ampl 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms 3.0 Vrms
1
Output termination set using front panel controls. HIGH Z assumes no load on output. 50W assumes a 50W 0.1W load on output.
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Chapter 4 Calibration Procedures AM Modulation Depth Verification
AM