Agilent U2761A USB Modular Function/Arbitrary Waveform Generator User’s Guide Agilent Technologies
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Environment Conditions This instrument is designed for indoor use and in the area with low condensation. The table below shows the general environmental requirements for this instrument. CAUTION Requirements Operating temperature 0 °C to 50 °C Operating humidity 20 to 85% RH non-condensing Storage temperature –20 °C to 70 °C Storage humidity 5 to 90% RH non-condensing The U2761A USB modular function/arbitrary waveform generator complies with the following safety and EMC requirements.
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In This Guide… 1 Getting Started In this chapter, you prepare your system for installation and configuration to get started with the U2761A. 2 Features and Functions In this chapter, you will learn about the functions and features offered by the U2761A. 3 Characteristics and Specifications In this chapter, you will observe the product characteristics and specifications.
Contents 1 Getting Started 1 Introduction 2 Product at a Glance 3 Product Outlook 3 Product Dimensions 5 Dimensions Without Bumpers 5 Dimensions With Bumpers 6 Standard Purchase Items 7 Inspection and Maintenance 8 Initial Inspection 8 Electrical Check 8 General Maintenance 8 Installation and Configuration 9 Installation 9 A. Check Your System 10 B. Install the IO Libraries Suite 11 C. Install the Module Driver 12 D. Install the Agilent Measurement Manager 13 E. Connect the Module to Your PC 15 F.
Output Frequency 29 Output Amplitude 31 DC Offset Voltage 33 Output Units 35 Output Termination 36 Duty Cycle (Square Waves) 38 Symmetry (Ramp Wave) 40 Output Control 41 Set Output Using SCPI Commands 42 Pulse Waveform 45 Pulse Period 45 Pulse Width 46 Pulse Duty Cycle 47 Generate Pulse Waveform Using SCPI Commands 48 Amplitude Modulation (AM) 49 To Select AM 49 Carrier Waveform 50 Carrier Frequency 51 Modulating Waveform 52 Modulating Waveform Frequency 53 Modulation Depth 53 Generate AM Using SCPI Command
To Select PM 61 Carrier Waveform 62 Carrier Frequency 63 Modulating Waveform 64 Modulating Waveform Frequency 64 Phase Deviation 65 Generate PM Using SCPI Commands 65 Frequency-Shift Keying (FSK) Modulation 66 To Select FSK Modulation 66 Carrier Waveform 67 FSK Carrier Frequency 68 FSK “Hop” Frequency 69 Generate FSK Modulation Using SCPI Commands 70 Phase-Shift Keying (PSK) Modulation 71 To Select PSK Modulation 71 Carrier Waveform 72 PSK Carrier Frequency 73 PSK Rate 74 PSK Deviation 74 Generate PSK Modul
Sweep Trigger Source 83 Set Frequency Sweep Using SCPI Commands 84 Triggering 85 Trigger Source Choices 85 Internal Triggering 86 Manual Triggering 86 External Triggering 87 Trigger Input Signal 88 Trigger Output Signal 88 Set Triggering Using SCPI Commands 90 Arbitrary Waveforms 91 To Create and Store an Arbitrary Waveform 91 3 Characteristics and Specifications 95 Product Characteristics 96 Product Specifications and Characteristics 97 Index XIV 103 U2761A User's Guide
List of Figures Figure 1-1 55-pin backplane connector pin configuration 23 Figure 2-1 U2761A soft front panel 28 Figure 2-2 Top panel view of the U2761A 29 Figure 2-3 Panel view of the frequency section 30 Figure 2-4 Panel view of the amplitude section 32 Figure 2-5 Panel view of the DC offset section 34 Figure 2-6 Panel view of the Tools menu 37 Figure 2-7 Square wave duty cycles 38 Figure 2-8 Panel view of the duty cycle section 39 Figure 2-9 Ramp wave duty cycles 40 Figure 2-10 Panel view of the symmetry
Figure 2-30 Trigger output pulse 88 Figure 2-31 Ramp waveform 91 Figure 2-32 Waveform download in progress 93 XVI U2761A User’s Guide
List of Tables Table 1-1 Synchronous Simultaneous Interface (SSI) connector pin description 23 Table 2-1 Output functions 26 Table 2-2 Output frequency range 29 Table 2-3 Carrier frequency for AM 51 Table 2-4 Carrier frequency for FM 57 Table 2-5 Carrier frequency for PM 63 Table 2-6 Carrier frequency for FSK 68 Table 2-7 “Hop” frequency 69 Table 2-8 Carrier frequency for PSK 73 Table 2-9 Carrier frequency for ASK 78 U2761A User’s Guide XVII
XVIII U2761A User’s Guide
Agilent U2761A USB Modular Function/Arbitrary Waveform Generator User’s Guide 1 Getting Started Introduction 2 Product at a Glance 3 Product Dimensions 5 Standard Purchase Items 7 Inspection and Maintenance 8 Installation and Configuration 9 This chapter provides the introduction of the U2761A that helps you get acquainted with the product and the product outlook. This chapter also includes the installation and configuration procedures that will help you get started with the U2761A.
1 Getting Started Introduction The U2761A is a 20 MHz USB modular function generator with Arbitrary waveform and pulse generation capabilities. It can operate as a standalone unit or as part of a modular unit when used with the U2781A USB modular instrument chassis. The U2761A adopts the latest direct digital synthesis (DDS) technology that digitally creates Arbitrary waveforms and frequencies from a single, fixed source frequency.
Getting Started 1 Product at a Glance Product Outlook Top View Bumpers U2761A User’s Guide 3
1 Getting Started Front View USB indicator Power indicator 10 MHz reference connector Trigger in connector Output connector Trigger out connector Rear View Fan Ventilation 55-pin backplane connector USB inlet Fastening hole for USB cable with locking mechanism Power inlet 4 U2761A User’s Guide
Getting Started 1 Product Dimensions Dimensions Without Bumpers Top View 105.00 mm 175.00 mm 18.00 mm Front View 25.
1 Getting Started Dimensions With Bumpers Top View 117.00 mm 180.00 mm 15.00 mm Front View 41.
Getting Started 1 Standard Purchase Items Verify the following items for the standard purchase of the U2761A. If there are any missing or mechanically damaged items, contact the nearest Agilent Sales Office.
1 Getting Started Inspection and Maintenance Initial Inspection When you receive your U2761A, inspect the unit for any obvious damage such as broken terminals or cracks, dents, and scratches on the casing that may occur during shipment. If any damage is found, notify the nearest Agilent Sales Office immediately. The front of this manual contains the warranty information. Keep the original packaging in case the U2761A has to be returned to Agilent in the future.
Getting Started 1 Installation and Configuration Installation Follow the step-by-step instructions shown in the following flowchart to get started with the preparations and installations of your U2761A. NOTE You need to install the IVI-COM driver if you are going to use the U2761A with Agilent VEE Pro, LabVIEW, or Microsoft® Visual Studio®. A. Check Your System B. Install the IO Libraries Suite C. Install the Module Driver D. Install the Agilent Measurement Manager E.
1 Getting Started A. Check Your System Prior to any installation or configuration, please ensure that your PC meets the following minimum system requirements. Processor 1.6 GHz Pentium® IV or higher Operating system Windows® XP Professional or Home Edition (Service Pack 1 or later), or Windows® 2000 Professional (Service Pack 4 or later) Browser Microsoft® Internet Explorer 5.
Getting Started 1 B. Install the IO Libraries Suite The IO Libraries Suite 14.2 or higher is available on the Agilent Automation-Ready CD that comes with the standard purchase of the U2761A. NOTE • If you do not have the Agilent Automation-Ready CD, obtain the IO Libraries Suite 14.2 or higher at http://www.agilent.com/find/iolib. • Disconnect any USB instruments or connectivity interface from your PC.
1 Getting Started C. Install the Module Driver NOTE Please ensure that there are no instruments connected to the PC when installing the driver. 1 Verify that your PC meets the minimum system requirements as stated in “A. Check Your System” on page 10. 2 Insert the Product Reference CD-ROM into your CD-ROM drive. 3 The installer will automatically launch the Agilent Modular Products Installation Menu. Click Hardware Driver to begin the installation.
Getting Started 1 6 Click Install to begin the installation. Follow the instructions on the screen to proceed with the installation. 7 Click Finish when the installation has completed. D. Install the Agilent Measurement Manager 1 If you have done “C. Install the Module Driver” on page 12, proceed to Step 2. If not, close all other applications on your PC and insert the Product Reference CD-ROM into your CD-ROM drive. 2 Click Measurement Manager on the U2761A Installation Menu to begin the installation.
1 Getting Started 6 Click OK to begin the installation of the listed missing prerequisites. 7 Once the above installation has completed, installation of the Measurement Manager software will proceed as normal. 8 The Measurement Manager InstallShield Wizard dialog will appear. Click Next to begin. 9 Read the License Agreement and select I accept the terms in the License Agreement to proceed. You may click Print to print a hardcopy of the Agilent License Terms for reference. Click Next to proceed.
Getting Started 1 E. Connect the Module to Your PC NOTE Ensure that the Agilent Measurement Manager is installed before proceeding. 1 After the installations have completed, connect the power cord to the AC/DC power adapter. The AC/DC power adapter requirements are 100 to 240 VAC, 50/60 Hz, with an output voltage of +12 VDC. 2 Insert the DC output plug from the AC/DC power adapter to the power jack on the rear panel of the U2761A.
1 Getting Started 5 Select Install the software automatically (Recommended) and click Next. 6 A warning message will appear on the Hardware Installation window. Click Continue Anyway to proceed with the installation of the U2761A.
Getting Started NOTE 1 If you do not wish to receive similar warning messages in the future, follow the instructions below. • Go to Start > Control Panel and double-click System. • Select the Hardware tab and click Driver Signing on the Drivers panel. The Driver Signing Options dialog box will appear. • Select Ignore to disable the warning message. 7 Click Finish to complete the installation.
1 Getting Started 8 The Assign USB device alias window will appear. Each time the U2761A is plugged in, this dialog box will appear. To disable this dialog, select the Never show this dialog option in the Show this dialog panel and click OK. 9 For modules other than the U2300A Series, U2500A Series, U2600A Series, and U2781A, the system will perform a firmware version check on your connected module.
Getting Started 1 c Click Yes to begin the firmware download. The following message box will appear indicating the download in progress. NOTE Ensure that you do not remove the USB and power connection until the firmware download has completed. d Your U2761A is ready for use once the firmware download has completed. F. Verify Your Module Connection The Agilent Connection Expert is one of the utilities in the IO Libraries.
1 Getting Started 3 A context menu will appear as shown below and select Send Commands To This Instrument. 4 The Agilent Interactive IO dialog box will appear. Click Send & Read to send the *IDN? default command. The instrument’s response should appear in the Instrument Session History panel. 5 If the Connection Expert can successfully communicate with the U2761A, this indicates that the instrument is installed correctly.
Getting Started 1 G. Launch Your Agilent Measurement Manager NOTE • The IO Control will launch automatically when you start your PC. • Launching the Measurement Manager without the IO Control running will cause failure of the Measurement Manager to detect or establish any connection with the U2761A connected to your PC. • To run the IO Control, go to Start > All Programs > Agilent IO Libraries Suite > Utilities > IO Control.
1 Getting Started 3 The Select USB Device dialog box will appear displaying the connected U2761A devices. To start the application, select a U2761A device and click OK to establish the connection. NOTE 22 For more information on how to use the Measurement Manager, refer to the Agilent Measurement Manager help file.
Getting Started 1 55-Pin Backplane Connector Pin Configuration The 55-pin backplane connector is used when the U2761A module is inserted into the U2781A USB modular instrument chassis. For more details, refer to the Agilent U2781A USB Modular Instrument Chassis User's Guide.
1 Getting Started Chassis Installation The L-mount kit is to be installed to your U2761A module. The following instructions describe the simple procedure of installing the L-mount kit and your module in the U2781A chassis. 1 Unpack the L-mount kit from its packaging. 2 Remove your U2761A module from the bumper casing. 3 Using a Phillips screwdriver, fasten the L-Mount kit to your U2761A module.
Agilent U2761A USB Modular Function/Arbitrary Waveform Generator User’s Guide 2 Features and Functions Output Configuration 26 Pulse Waveform 45 Amplitude Modulation (AM) 49 Frequency Modulation (FM) 55 Phase Modulation (PM) 61 Frequency-Shift Keying (FSK) Modulation 66 Phase-Shift Keying (PSK) Modulation 71 Amplitude-Shift Keying (ASK) Modulation 76 Frequency Sweep 80 Triggering 85 Arbitrary Waveforms 91 In this chapter, you will learn about the functions and features offered by the U2761A.
2 Features and Functions Output Configuration Introduction This section contains the information to help you configure the U2761A for outputting waveforms. You may not need to change some of the parameters discussed here, but they are provided so that you will have accessibility when needed. Output Function The U2761A can output five standard waveforms (Sine, Square, Ramp, Triangle, and Pulse), and DC. You can select one of the three built-in Arbitrary waveforms or create your own custom waveforms.
Features and Functions 2 Function Limitation If you change to a function where the maximum frequency is less than the current function, the frequency will be adjusted to the maximum value for the new function. For example, if you are currently outputting a 20 MHz sine wave and then change to the Ramp function, the U2761A will automatically adjusts the output frequency to 200 kHz (the upper limit for Ramp).
2 Features and Functions Soft Front Panel Operation The following figure shows the soft front panel of the U2761A.
Features and Functions 2 To select a function, click any of the functions on the top panel as shown below. When a function is selected, the button will be illuminated. Figure 2-2 Top panel view of the U2761A Click Arb to output the Arbitrary waveform. Select other Arbitrary waveform choices from the drop down list . Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|PULSe|DC|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset.
2 Features and Functions Function Limitations If you change to a function where the maximum frequency is less than the current function, the frequency will be adjusted to the maximum value for the new function. For example, if you are currently outputting a 20 MHz sine wave and then change to the Ramp function, the U2761A will automatically adjusts the output frequency to 200 kHz (the upper limit for Ramp).
Features and Functions 2 Remote Interface Operation FREQuency You can also use the APPLy command to select the function, frequency, amplitude, and offset. Output Amplitude The default amplitude is 1 Vpp (into 50 Ω) for all functions. Offset Voltage Limitations The relation between the output amplitude and offset voltage is shown below. Vmax is the maximum peak voltage for the selected output termination (5 V for a 50 Ω load or 10 V for a high-impedance load).
2 Features and Functions Limits Due to Units Selection In some cases, the amplitude limits are determined by the output units selected. This may occur when the units are Vrms or dBm due to the differences in crest factor for the various output functions. For example, if you output a 2.5 Vrms Square wave (into 50 Ω) and then change to the Sine wave function, the U2761A will automatically adjusts the output amplitude to 1.768 Vrms (the upper limit for Sine wave in Vrms).
Features and Functions 2 Remote Interface Operation VOLTage Or, you can set the amplitude by specifying a high level and low level using the following commands. VOLTage:HIGH VOLTage:LOW You can also use the APPLy command to select the function, frequency, amplitude, and offset. DC Offset Voltage The default offset is 0 V for all functions. Limits Due to Amplitude The relation between the offset voltage and output amplitude is shown below.
2 Features and Functions Soft Front Panel Operation On the Offset panel as shown in Figure 2- 5, input the desired offset value and select the unit from the drop down list. Figure 2-5 Panel view of the DC offset section Remote Interface Operation VOLTage:OFFSet Or, you can set the offset by specifying a high level and low level using the following commands. VOLTage:HIGH VOLTage:LOW You can also use the APPLy command to select the function, frequency, amplitude, and offset.
Features and Functions 2 Output Units This configuration applies to output amplitude only. At power-on, the units for output amplitude are volts peak-to-peak. • The output units consist of Vpp, Vrms, or dBm. The default unit is Vpp. • The unit setting is stored in volatile memory. The units are set to “Vpp” upon power-off or after a remote interface reset. • The output units for amplitude cannot be set to dBm if the output termination is currently set to “high impedance”.
2 Features and Functions Output Termination This configuration applies to output amplitude and offset voltage only. The U2761A has a fixed series output impedance of 50 Ω to the device output connector. If the actual load impedance is different from the specified value, the amplitude and offset levels will be incorrect. • The range of the output termination is 1 Ω to 10 kΩ, or Infinite. The default value is 50 Ω.
Features and Functions 2 Soft Front Panel Operation Click Tools and select Waveform Gen as shown in the following. Figure 2-6 Panel view of the Tools menu Then, select the Output Setup tab, input the desired load impedance value on the Impedance Load panel and select the unit from the drop down list, or select High Z for high impedance load.
2 Features and Functions Duty Cycle (Square Waves) The duty cycle of a Square wave represents the amount of time per cycle that the Square wave is at a high level (assuming that the waveform is not inverted). 20% Duty Cycle 80% Duty Cycle Figure 2-7 Square wave duty cycles Refer to “Pulse Waveform” on page 45 for the information on the duty cycle for Pulse waveforms.
Features and Functions 2 The duty cycle setting does not apply to a Square waveform used as the modulating waveform for AM, FM, or PM. A 50% duty cycle is always used for a modulating Square waveform. The duty cycle setting applies only to a Square waveform carrier. Soft Front Panel Operation After selecting Square at the top panel as shown in Figure 2- 2, on the Duty Cycle panel below, input the desired duty cycle value.
2 Features and Functions Symmetry (Ramp Wave) This configuration applies to Ramp wave only. Symmetry represents the amount of time per cycle that the Ramp wave is rising (assuming that the waveform is not inverted). 0% Symmetry 100% Symmetry Figure 2-9 Ramp wave duty cycles • The symmetry percentage is stored in volatile memory where the symmetry is set to default 100% upon power-off or after a remote interface reset. • The symmetry setting is stored when you change from Ramp wave to another function.
Features and Functions 2 Remote Interface Operation FUNCtion:RAMP:SYMMetry The APPLy command automatically sets the symmetry to 100%. Output Control You can disable or enable the soft front panel output control. By default, the output is disabled at power-on. When enabled, the Output button is illuminated. If an excessive external voltage is applied to the device output connector, the output will be disabled.
2 Features and Functions Remote Interface Operation OUTPut {0|OFF|1|ON} The APPLy command overrides the current setting and automatically enables the output control. Set Output Using SCPI Commands The following SCPI commands show a sample procedure of generating output. Example 1, To output a DC voltage 42 -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FUNC DC //Sets the output to DC.
Features and Functions 2 Example 2, To output a Sine wave -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FUNC SIN //Sets the output to Sine wave. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> FREQ 1000 //Sets the output frequency to 1 kHz. -> VOLT:OFFS 0 //Sets the output offset to 0. -> OUTP ON //Turns on output.
2 Features and Functions Example 4, To output a Ramp wave -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FUNC RAMP //Sets the output to Ramp wave. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> FREQ 10000 //Sets the output frequency to 10 kHz. -> VOLT:OFFS 0 //Sets the output offset to 0. -> FUNC:RAMP:SYMM 50 //Changes the symmetry to 50%. -> OUTP ON 44 //Turns on output.
Features and Functions 2 Pulse Waveform As shown below, a Pulse waveform consists of a period, a pulse width, a rising edge, and a falling edge. 90% 90% 50% 50% Pulse width 10% 10% Rise time Fall time Period Figure 2-12 Pulse waveform Pulse Period The range of the pulse period is from 200 ns to 2000 s. The default value is 1 ms. The U2761A will adjusts the pulse width as necessary to accommodate the specified period.
2 Features and Functions Pulse Width The pulse width represents the time from the 50% threshold of the pulse’s rising edge to the 50% threshold of the next falling edge. • The range of the pulse width is 40 ns to <2000 s (see restrictions below). The default pulse width is 500 μs. • The minimum pulse width (Wmin) is affected by the period.
Features and Functions 2 Pulse Duty Cycle The pulse duty cycle is defined as: Duty Cycle = 100 × Pulse Width / Period where the pulse width represents the time from the 50% threshold of the rising edge of the pulse to the 50% threshold of the next falling edge. • Pulse duty cycle: >0% to <100% (see restrictions below). The default is 50%. • The specified pulse duty cycle must conform to the following restrictions determined by the minimum pulse width (Wmin).
2 Features and Functions Generate Pulse Waveform Using SCPI Commands Example 1 -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FUNC PULS //Sets the output to Pulse wave. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> VOLT:OFFS 0 //Sets the output offset to 0. -> PULS:PER 1 //Sets the pulse period to 1 s. -> FUNC:PULS:DCYC 50 //Set the pulse duty cycle to 50%. -> OUTP ON 48 //Turns on output.
Features and Functions 2 Amplitude Modulation (AM) A modulated waveform consists of a carrier waveform and a modulating waveform. An example of the AM waveform is shown in Figure 2- 14. In AM, the amplitude of the carrier is varied by the instantaneous voltage of the modulating waveform. The amount of amplitude modulation is called the modulation depth which refers to the portion of the amplitude range that will be used by the modulation.
2 Features and Functions Soft Front Panel Operation Click Mod and then select AM as shown in Figure 2- 15. To output the AM waveform, configure the settings for the carrier frequency, modulating frequency, depth, output amplitude, offset voltage, and the desired waveform. Figure 2-15 Panel view of AM Remote Interface Operation AM:STATe {0|OFF|1|ON} Carrier Waveform The AM carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default waveform is Sine wave.
Features and Functions 2 Figure 2-16 Panel view of the Arbitrary waveform Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. Carrier Frequency The maximum carrier frequency depends on the selected function as shown below. The default frequency is 1 kHz for all functions.
2 Features and Functions Soft Front Panel Operation On the Frequency panel as shown in Figure 2- 3, input the desired frequency value and select the unit from the drop down list. Remote Interface Operation FREQuency You can also use the APPLy command to select the function, frequency, amplitude, and offset. Modulating Waveform The modulating waveform consists of Sine, Square, Ramp, Negative Ramp (Nramp), Triangle, or Arbitrary waveform. The default modulating waveform is Sine wave.
Features and Functions 2 Modulating Waveform Frequency The range of the modulating waveform frequency is 2 mHz to 20 kHz. The default modulating waveform frequency is 100 Hz. Soft Front Panel Operation On the Mod Frequency panel as shown in Figure 2- 15, input the desired modulating frequency value and select the unit from the drop down list.
2 Features and Functions Generate AM Using SCPI Commands Example 1 54 -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> AM:STAT ON //Enables AM. -> FUNC SQU //Sets the carrier waveform to Square wave. -> FREQ 2000 //Sets the carrier frequency to 2 kHz. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> VOLT:OFFS 0 //Sets the output offset to 0.
Features and Functions 2 Frequency Modulation (FM) A modulated waveform consists of a carrier waveform and a modulating waveform. Below shows an example of the FM waveform. In FM, the frequency of the carrier is varied by the instantaneous voltage of the modulating waveform. The variation in frequency of the modulated waveform from the carrier frequency is called the frequency deviation.
2 Features and Functions Soft Front Panel Operation Click Mod and then select FM as shown in Figure 2- 18. To output the FM waveform, configure the settings for the carrier frequency, output amplitude, offset voltage, modulating frequency, deviation, and the desired waveform. Figure 2-18 Panel view of FM Remote Interface Operation FM:STATe {0|OFF|1|ON} Carrier Waveform The FM carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default waveform is Sine wave.
Features and Functions 2 Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. Carrier Frequency The maximum carrier frequency depends on the selected function as shown below. The default is 1 kHz for all functions.
2 Features and Functions Soft Front Panel Operation On the Frequency panel as shown in Figure 2- 3, input the desired frequency value and select the unit from the drop down list. Remote Interface Operation FREQuency You can also use the APPLy command to select the function, frequency, amplitude, and offset. Modulating Waveform The modulating waveform consists of Sine, Square, Ramp, Negative Ramp (Nramp), Triangle, Noise, or Arbitrary waveform. The default modulating waveform is Sine wave.
Features and Functions 2 Modulating Waveform Frequency The range of the modulating waveform frequency is 2 mHz to 20 kHz. The default modulating waveform frequency is 100 Hz. Soft Front Panel Operation On the Mod Frequency panel as shown in Figure 2- 18, input the desired modulating frequency value and select the unit from the drop down list.
2 Features and Functions Soft Front Panel Operation On the Deviation panel as shown in Figure 2- 18, input the desired frequency deviation value and select the unit from the drop down list. Remote Interface Operation FM:DEViation Generate FM Using SCPI Commands Example 1 60 -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FM:STAT ON //Enables FM.
Features and Functions 2 Phase Modulation (PM) A modulated waveform consists of a carrier waveform and a modulating waveform. The following figure shows an example of a PM waveform. PM is very similar to FM, but in PM, the phase of the modulated waveform is varied by the instantaneous voltage of the modulating waveform. The variation in phase of the modulated waveform from the carrier waveform is called the phase deviation.
2 Features and Functions Soft Front Panel Operation Click Mod and then select PM as shown in Figure 2- 20. To output the PM waveform, configure the settings for the carrier frequency, output amplitude, offset voltage, modulating frequency, phase deviation, and the desired waveform. Figure 2-20 Panel view of PM Remote Interface Operation PM:STATe {0|OFF|1|ON} Carrier Waveform The PM carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default waveform is Sine wave.
Features and Functions 2 Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. Carrier Frequency The maximum carrier frequency depends on the function selected as shown below. The default carrier frequency is 1 kHz for all functions.
2 Features and Functions Modulating Waveform The modulating waveform consists of Sine, Square, Ramp, Negative Ramp (Nramp), Triangle, or Arbitrary waveform. The default waveform is Sine wave. • Square has 50% duty cycle • Ramp has 100% symmetry • Triangle has 50% symmetry • Negative Ramp has 0% symmetry Soft Front Panel Operation Select the desired modulating waveform from the drop down list as shown in Figure 2- 20.
Features and Functions 2 Phase Deviation The phase deviation setting represents the peak variation in phase of the modulated waveform from the carrier waveform. The phase deviation setting can be set from 0 to 360°. The default phase deviation setting is 180°. Soft Front Panel Operation On the Phase Deviation panel as shown in Figure 2- 20, input the desired phase deviation value.
2 Features and Functions Frequency-Shift Keying (FSK) Modulation FSK is similar to FM except that the frequency alternates between two preset values. You can configure the U2761A to “shift” its output frequency between two preset values using FSK modulation. An example of the FSK modulation waveform is shown below. The rate at which the output shifts between the two frequencies (called the “carrier frequency” and the “hop frequency”) is determined by the internal rate generator.
Features and Functions 2 Soft Front Panel Operation Click Mod and select FSK as shown in Figure 2- 22. To output the FSK waveform, configure the settings for the carrier frequency, output amplitude, offset voltage, “hop frequency”, and FSK rate. Figure 2-22 Panel view of FSK Remote Interface Operation FSKey:STATe {0|OFF|1|ON} Carrier Waveform The FSK carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default carrier waveform is Sine wave.
2 Features and Functions Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. FSK Carrier Frequency The maximum carrier frequency depends on the function selected as shown below. The default carrier frequency is 1 kHz for all functions.
Features and Functions 2 FSK “Hop” Frequency The maximum alternate (or “hop”) frequency depends on the function selected as shown below. The default “hop” frequency is 100 Hz for all functions. Table 2-7 “Hop” frequency Function Minimum frequency Maximum frequency Sine 1 μHz 20 MHz Square 1 μHz 20 MHz Ramp, Triangle 1 μHz 200 kHz Arbitrary 1 μHz 200 kHz Only Square wave with a 50% duty cycle is available for the Internal FSK modulating waveform.
2 Features and Functions FSK Rate The FSK rate is the rate at which the output frequency “shifts” between the carrier frequency and the hop frequency. • The range of the FSK rate is 2 mHz to 100 kHz. The default FSK rate value is 10 Hz. Soft Front Panel Operation On the FSK Rate panel as shown in Figure 2- 22, input the desired FSK rate value and select the unit from the drop down list.
Features and Functions 2 Phase-Shift Keying (PSK) Modulation Phase-shift keying (PSK) is a form of digital modulation in which the phase of the carrier signal is discretely varied. You can configure the U2761A to “shift” its output phase between two preset phases using PSK. The rate at which the output shifts between the two phases is determined by the internal rate generator on the signal level. The following figure shows an example of the PSK modulation waveform.
2 Features and Functions Soft Front Panel Operation Click Mod and then select PSK as shown in Figure 2- 24. To output the PSK waveform, configure the settings for the carrier frequency, output amplitude, offset voltage, deviation, and PSK rate. Figure 2-24 Panel view of PSK Remote Interface Operation PSKey:STATe {0|OFF|1|ON} Carrier Waveform The PSK carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default waveform is Sine wave.
Features and Functions 2 Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. PSK Carrier Frequency The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.
2 Features and Functions PSK Rate The PSK rate is the rate at which the output phase “shifts” between two preset phases. The range of the PSK rate is 2 mHz to 100 kHz. The default PSK rate value is 10 Hz. Soft Front Panel Operation On the PSK Rate panel as shown in Figure 2- 24, input the desired PSK rate value and select the unit from the drop down list.
Features and Functions 2 Generate PSK Modulation Using SCPI Commands Example 1 U2761A User’s Guide -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> PSK:STAT ON //Enables PSK modulation. -> FUNC SIN //Sets the carrier waveform to Sine wave. -> FREQ 1000 //Sets the carrier frequency to 1 kHz. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> VOLT:OFFS 0 //Sets the output offset to 0.
2 Features and Functions Amplitude-Shift Keying (ASK) Modulation ASK is a form of digital modulation in which the modulating signal apply variations in the amplitude of a carrier signal. The amplitude of the carrier signal varies simultaneously with the modulating signal while phase and frequency remain constant. In other words, the carrier signal can be assumed as an on and off switch. You can configure the U2761A to “shift” its output amplitude between two preset amplitudes using ASK.
Features and Functions 2 Soft Front Panel Operation Click Mod and then select ASK as shown in Figure 2- 26. To output the ASK waveform, configure the settings for the carrier frequency, output amplitude, offset voltage, and ASK rate. Figure 2-26 Panel view of ASK Remote Interface Operation ASKey:STATe {0|OFF|1|ON} Carrier Waveform The ASK carrier waveform consists of Sine, Square, Ramp, Triangle, or Arbitrary waveform. The default waveform is Sine wave.
2 Features and Functions Remote Interface Operation FUNCtion {SINusoid|SQUare|RAMP|USER} You can also use the APPLy command to select the function, frequency, amplitude, and offset. Carrier Frequency The maximum carrier frequency depends on the function selected as shown below. The default is 1 kHz for all functions.
Features and Functions 2 ASK Rate The ASK rate is the rate at which the output amplitude “shifts” between two preset amplitudes. The range of the ASK rate is 2 mHz to 100 kHz. The default ASK rate value is 10 Hz. Soft Front Panel Operation On the ASK Rate panel as shown in Figure 2- 26, input the desired ASK rate value and select the unit from the drop down list.
2 Features and Functions Frequency Sweep In the frequency sweep mode, the U2761A “steps” from the start frequency to the stop frequency at a sweep rate which you specify. You can sweep up or down in frequency, and with either linear or logarithmic spacing. You can also configure the U2761A to output a single sweep (one pass from start frequency to stop frequency) by applying an External or Manual (software) trigger.
Features and Functions 2 Figure 2-28 Panel view of sweep Remote Interface Operation SWEep:STATe {0|OFF|1|ON} Start Frequency and Stop Frequency The start frequency and stop frequency sets the upper and lower frequency bounds for the sweep. The U2761A begins at the start frequency, sweeps to the stop frequency, and then resets back to the start frequency. • The range of the start and stop frequencies is 1 μHz to 20 MHz (limited to 200 kHz for Ramp and Arbitrary waveforms).
2 Features and Functions Remote Interface Operation FREQuency:STARt FREQuency:STOP Sweep Mode You can sweep with either linear or logarithmic spacing. For a linear sweep, the U2761A varies the output frequency in a linear fashion during the sweep. For a logarithmic sweep, the U2761A varies the output frequency in a logarithmic fashion. The sweep mode consists of Linear or Logarithmic. The default sweep mode is Linear.
Features and Functions 2 Soft Front Panel Operation On the Sweep Time panel as shown in Figure 2- 28, input the desired sweep time and select the unit from the drop down list. Remote Interface Operation SWEep:TIME Sweep Trigger Source In the sweep mode, the U2761A outputs a single sweep when a trigger signal is received.
2 Features and Functions To specify whether the U2761A is triggered on the rising or falling edge of the signal from the Trig In connector, select Positive for rising edge triggering and Negative for falling edge triggering. Remote Interface Operation TRIGger:SOURce {IMMediate|EXTernal|BUS} Use the following command to specify whether the U2761A is triggered on the rising or falling edge of the signal from the Trig In connector.
Features and Functions 2 Triggering Applies to sweep only. You can issue triggers for sweeps using Internal (immediate) triggering, External triggering, or Manual (software) triggering. • Internal triggering is enabled when you turn on the U2761A. In this mode, the U2761A outputs continuously when the sweep mode is selected. • External triggering uses the device Trig In connector to control the sweep. The U2761A initiates one sweep each time Trig In receives a TTL pulse.
2 Features and Functions Remote Interface Operation TRIGger:SOURce {IMMediate|EXTernal|BUS} Internal Triggering In the Internal trigger mode, the U2761A continuously performs frequency sweep (as specified by the sweep time). This is the default trigger source for both soft front panel and remote interface use. Soft Front Panel Operation On the Trigger Setup panel as shown in Figure 2- 28, select Internal from the drop down list at the Source panel.
Features and Functions 2 Remote Interface Operation TRIGger:SOURce BUS When the BUS source is selected, send the TRIG or *TRG command to trigger the U2761A. External Triggering In the External trigger mode, the U2761A accepts a hardware trigger applied to the device Trig In connector. The U2761A initiates one sweep each time Trig In receives a TTL pulse with the specified edge. Also refer to “Trigger Input Signal” on page 88.
2 Features and Functions Trigger Input Signal Trigger in Rising edge shown Figure 2-29 Trigger input pulse The device connector is used for Triggered Sweep Mode, refer to “Sweep Trigger Source” on page 83. When the rising or falling edge of the TTL pulse is received on the Trig In connector, the U2761A outputs a single sweep, refer to “External Triggering” on page 87. Trigger Output Signal A “trigger out” signal is provided on the device Trig Out connector (used with sweep only).
Features and Functions 2 When the Internal (immediate) trigger source is selected, the U2761A outputs a Square waveform with a 50% duty cycle to the Trig Out connector at the beginning of the sweep. The period of the Square waveform is equal to the specified sweep time. When the Manual (software) trigger source is selected, the U2761A outputs a pulse to the Trig Out connector at the beginning of each sweep.
2 Features and Functions Set Triggering Using SCPI Commands Example 1 90 -> *CLS; *RST //To reset the U2761A to default power-on state, this command can be ignored if this operation is not required. -> FUNC SIN //Sets the carrier waveform to Sine wave. -> VOLT 5 VPP //Sets the output amplitude to 5 Vpp. -> VOLT:OFFS 0 //Sets the output offset to 0. -> SWE:STAT ON //Enables frequency sweep. -> FREQ:STAR 500 //Changes the start frequency to 500 Hz.
Features and Functions 2 Arbitrary Waveforms There are three built-in Arbitrary waveforms offered. The U2761A supports the Arbitrary waveform up to 65536 (64K) data points. You can create an Arbitrary waveform using the soft front panel as described in the following. For further information, please refer to the Agilent Measurement Manager help file.
2 Features and Functions 1 Select the Arbitrary waveform function. Click Arb to select the Arbitrary function. 2 Set the waveform period. Select Period numeric drop down waveform. and use the numeric keypad or to set the period for the For example, set the period of the waveform to 10 ms. 3 Set the waveform voltage limits. Select HiLevel and Lolevel to set the high and low voltage levels that can be reached while editing the waveform. The upper limit must be greater than the lower limit.
Features and Functions 2 6 Start waveform editing process. Click to begin the freehand draw mode or to enable line draw mode. To enable or disable the grid reference, click . Then, start drawing the desired waveform. To edit the waveform, click either to add line/point(s), to edit point(s), to delete point(s), or to clear current Arbitrary graph. 7 Sending waveform to the U2761A. To send the waveform to the U2761A, click .
2 Features and Functions 8 Saving the waveform. To save the waveform for future use, click . Then, select Compatible With Intuilink and click . Input the desired file name and click to save the file. 9 Exiting the waveform editor. To exit the waveform editor, click 94 .
Agilent U2761A USB Modular Function/Arbitrary Waveform Generator User’s Guide 3 Characteristics and Specifications Product Characteristics 96 Product Specifications and Characteristics 97 This chapter specifies the characteristics, environmental conditions, and specifications of the U2761A.
3 Characteristics and Specifications Product Characteristics REMOTE INTERFACE • Hi-Speed USB 2.0 • USBTMC 488.
Characteristics and Specifications 3 Product Specifications and Characteristics WAVEFORMS Standard Sine, Square, Ramp, Triangle, Pulse, DC Built-in arbitrary Exponential Rise, Exponential Fall, Negative Ramp WAVEFORM CHARACTERISTICS Sine Frequency range 1 μHz to 20 MHz (1 μHz resolution) Amplitude flatness 1 <100 kHz (relative to 1 kHz) 100 kHz to 1 MHz 0.35 dB 1 MHz to 20 MHz 0.
3 Characteristics and Specifications Ramp, Triangle Frequency range 1 μHz to 200 kHz (1 μHz resolution) Linearity <0.2% of peak output Programmable symmetry 0% to 100% Pulse Frequency range 500 μHz to 5 MHz (1 μHz resolution) Pulse width (period ≤ 10 s) 40 ns minimum, 10 ns resolution Overshoot <3% Jitter (RMS) 300 ps + 0.
Characteristics and Specifications 3 COMMON CHARACTERISTICS Amplitude Range 40 mVpp to 5 Vpp (Into 50 Ω load) 80 mVpp to 10 Vpp (Into open circuit) Accuracy 1 (across 50 Ω load at 1 kHz) ±1% of settling ±5 mV (±10 mV @ Hi-Z) Units Vpp, Vrms, dBm Resolution 4 digits DC offset Range (peak AC + DC) ±2.
3 Characteristics and Specifications MODULATION AM Carrier waveforms Sine, Square, Ramp, Arbitrary Source Internal Internal modulation Sine, Square, Ramp, Arbitrary (2 mHz to 20 kHz) Depth 0.0% to 100.
Characteristics and Specifications 3 SWEEP CHARACTERISTICS Waveforms Sine, Square, Ramp, Arbitrary Type Linear or Logarithmic Direction Up or Down Sweep time 1 ms to 500 s Trigger Single, External, or Internal TRIGGER CHARACTERISTICS Trigger input Input level TTL compatible Slope Rising or Falling, Selectable Pulse width >100 ns Input impedance >10 kΩ, DC coupled Latency <500 ns Jitter (RMS) 6 ns (3.
3 102 Characteristics and Specifications U2761A User’s Guide
Index Index A bus trigger 89 Accuracy 99 Agilent Automation-Ready CD 7, 10, 11 Connection Expert 19 IO Libraries Suite 14.
Index L limits amplitude 27, 33 product dimensions 5, 96 outlook 3 Sweep 80 sweep mode 82 specifications 97 duty cycle 30 SCPI commands 84 frequency 38 Programmable symmetry 98 time 82, 83, 101 function 27, 30 protection 99 PSK carrier frequency 73 trigger source 83 offset voltage 31 output termination 31 carrier waveform 72, 100 units selection 32 deviation 74, 100 L-Mount kit 7, 24 O output amplitude 31, 33, 35, 36, 99 rate 74 frequency 29, 99 input signal 88, 101 Internal 85, 86, 89
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