Tektronix AFG1022 Function Generator



Tektronix AFG1022 Function Generator

Basic Information

Tektronix has released an official programming guide for the AFG1022 dual channel function generator, with the core goal of guiding users to achieve instrument automation control through SCPI (Standard Commands for Programmable Instruments), suitable for engineers who need to integrate AFG1022 into testing systems such as production line testing and laboratory automation.

Product core parameters: 2 independent channels, with a maximum bandwidth of 120MHz per channel, supporting 11 waveforms including sine wave, square wave, pulse wave, etc;

Supporting interfaces: GPIB (compliant with IEEE 488.2 standard), USB-TMC (USB 2.0 High Speed, compatible with USBTMC protocol);

Software compatibility: Supports mainstream VISA libraries such as TekVISA and NI-VISA, and can be called through programming languages such as Python, C #, LabVIEW, etc;

Document structure: Organized according to the sequence of "Command Fundamentals ->Function Control ->Interface Configuration ->Error Handling ->Appendix", containing a large number of command examples and code snippets.

SCPI Command Fundamentals (Programming Control Premiere)

1. Command structure and syntax rules

The SCPI command of AFG1022 adopts a hierarchical structure, separated by colons (:) to facilitate functional classification and memory. The core rules are as follows:

Example of Specific Explanation of Rule Categories

Hierarchical structure root command (e.g. SOURce)+sub command (e.g. FREQuency), channels can be omitted (default channel 1) Control channel 1 frequency: SOURce: FREQ 1000 (or SOURce: FREQ 1000); Control channel 2: SOURce2: FREQ 2000

Case sensitivity commands are not case sensitive, and parameter enumeration (such as ON/OFF) is also not sensitive: SOURce: WAVEform SIN is equivalent to: source: Waveform sin

The space rule allows for the addition of spaces between commands and parameters, as well as between parameters, without affecting parsing. SOURce: FREQ 1000 is equivalent to SOURce: FREQ 1000

The abbreviation rule command can use the first 3 characters for abbreviation (some commands support longer abbreviations): SOURce can be abbreviated as: SOU,: FREQuency can be abbreviated as: FRE

2. Command types and data formats

Command type:

Set command: used to configure instrument parameters, in the format of "command+parameter", with no return value;

Example: SOURce: VOLTage: AMPity 5 (set channel 1 amplitude to 5Vpp).

Query command: used to read the current parameters of the instrument, in the format of "command+question mark (?)", and return the corresponding value;

Example: SOURce: VOLTage: AMPlity? (Query the current amplitude of channel 1 and return "5.000000e+00").

Data format:

Example of Data Type Format Requirements

Numerical type supports integer (1000), decimal (1.234), Scientific notation (1e6) frequency setting: SOURCE: FREQ 1.234e6 (1.234MHz)

String type needs to be enclosed in double quotation marks ("), supporting letters, numbers, and special characters. Save settings: SYSTem: SETup: SAVE" MY_STUP1“

Enumeration type predefined options that require strict matching (case insensitive) waveform selection: SOURce: WAVEform SQUare, SOURce: WAVEform TRIangle

Core functional programming control (divided by functional modules)

1. Basic waveform generation and parameter control

AFG1022 supports 11 standard waveforms, and can select waveform types and configure core parameters (frequency, amplitude, DC offset, etc.) through SCPI commands. The parameter range and corresponding commands are as follows:

Function module core parameter range control command (channel 1 as an example) query command

11 types of waveform selection, including sine wave (SINusoid), square wave (SQUare), pulse wave (PULSe), etc.: SOURCE: WAVEform SINusoid: SOURCE: WAVEform?

Frequency setting output frequency: 0.1Hz~120MHz (sine wave/square wave); 0.1Hz~10MHz (pulse wave): SOURce: FREQuency 1000 (1kHz): SOURce: FREQuency?

Amplitude setting peak to peak amplitude of 10mVpp~20Vpp (50 Ω load); 20mVpp~40Vpp (high impedance load): SOURce: VOLTage: AMPlity 5 (5Vpp): SOURce: VOLTage: AMPlity?

DC offset DC offset voltage ± 10V (50 Ω load); ± 20V (high impedance load): SOURce: VOLTage: OFFset 2 (+2V): SOURce: VOLTage: OFFset?

Square wave duty cycle, such as wave height to level ratio of 10% to 90% (frequency ≤ 10MHz): SOURce: PULSe: DCYCle 50 (50%): SOURce: PULSe: DCYCle?

2. Advanced Function Control

(1) Modulation function (AM/FM/PM)

Support amplitude modulation (AM), frequency modulation (FM), phase modulation (PM), configurable modulation source (internal/external), modulation depth and other parameters:

Enable modulation: SOURce: MOD: STATe ON;

Select modulation type: SOURce: MOD: TYPE AM (AM modulation);

Configure internal modulation source frequency: SOURce: MOD: INTernal: FREQ 100 (100Hz modulation signal);

Configure AM modulation depth: SOURce: MOD: AM: DEPTh 50 (50% modulation depth).

(2) Trigger and synchronization

Supports internal triggering (continuous output), external triggering (controlled by external signals), and software triggering, suitable for synchronous multi device testing:

Select trigger source: TRIGger: SURce EXTernal (external trigger, trigger signal connected to TRIG IN interface of Rear panel);

Set trigger edge: TRIGger: EDGE RISING (rising edge trigger);

Execute software trigger: TRIGger: IMMediate (immediately trigger output once);

Trigger delay: TRIGger: DELay 0.1 (output delayed by 0.1 seconds after triggering).

(3) Setting up storage and calling

The current instrument configuration (waveform, parameters, modulation, etc.) can be saved to the internal storage area (supporting 10 user settings), and can be directly called later:

Save settings: SYSTem: SETup: SAVE "SET1", 1 (Save current settings as "SET1", Store location 1);

Call settings: SYSTem: SETup: LOAD 1 (setting to call storage location 1);

Delete setting: SYSTem: SETup: DELETE 1 (delete storage location 1 setting).

3. Multi channel control (AFG1022 has 2 channels)

Two channels are independently controllable, and channel 2 can be distinguished by adding 2 in the command. The example is as follows:

Channel 2 waveform selection: SOURce2: WAVEform TRIangle (Channel 2 outputs triangular waves);

Channel 2 frequency setting: SOURce2: FREQ 2000 (channel 2 frequency 2kHz);

Channel synchronization: SOURce: SYNC: STATe ON (synchronizes channel 2 with channel 1 in phase).

Interface configuration and communication implementation

1. Supported communication interfaces

AFG1022 provides two programming interfaces to meet different testing system requirements:

Advantages of Interface Type Standard Protocol Hardware Requirements

GPIB IEEE 488.2 requires GPIB cards (such as NI GPIB-US-HS) with strong anti-interference capabilities, suitable for industrial environments

USB-TMC USB 2.0 High Speed+USBTMC standard USB cable (A-B type) plug and play, no additional hardware required

2. Communication parameter configuration

GPIB interface: default address is 22, baud rate is 115200, data bit is 8, stop bit is 1, checksum is None; The address can be modified by the command: SYSTem: GPIB: DDRess 23 (set to 23).

USB-TMC interface: No manual parameter configuration is required, the system automatically recognizes it as a "USBTMC device" and can be directly connected through the VISA library (the resource name is usually USB0:: 0x0699:: 0x0368: C012345:: 0:: INSTR).

3. Typical Communication Example (Python+pyvisa)

Taking "Generate 1kHz sine wave and query amplitude" as an example, the steps are as follows:

Install dependency library: pip install pyvisa pyvisa py;

Write code:

python

Import pyvisa # Import VISA library

# 1. Initialize Resource Manager

rm = pyvisa.ResourceManager()

# 2. Connect AFG1022 (resource name can be queried through rm.list_desources())

afg = rm.open_resource("USB0::0x0699::0x0368::C012345::0::INSTR")

# 3. Send command: Channel 1 outputs a 1kHz sine wave with an amplitude of 5Vpp

Afg.write ("SOURce: WAVEform SINusoid") # Select sine wave

Afg.write ("SOURce: FREQuency 1000") # Frequency 1kHz

Afg.write ("SOURce: VOLTage: AMPlity 5") # amplitude 5Vpp

Afg. write (": OUTPut: STATe ON") # Enable output

# 4. Query the current amplitude

amplitude = afg.query(":SOURce:VOLTage:AMPlitude?")

Print (f "Current amplitude: {amplitude} Vpp")

# 5. Close connection

afg.close()

rm.close()

Generating

Error handling and debugging

1. Error code query and parsing

When the instrument executes a command error (such as parameter out of range, syntax error), an error code will be recorded, which can be queried and located through the command:

Query error: SYSTem: ERRor? (Return format: -221, "Parameter out of range");

Common error code parsing:

Error code, error description, possible causes, and solutions

-221 Parameter out of range Check if the parameter is within the specified range (e.g. frequency ≤ 120MHz)

-102 Syntax error command syntax error check command spelling (e.g. SOURce: FREQ mistakenly written as SOURce: FRE)

-256 Calibration required: The instrument has not been calibrated and the accuracy of the parameters cannot be guaranteed. Execute the calibration command (SYSTem: CALibrate) or contact after-sales service

0 No error command executed successfully-

2. Status Register and Status Query

By reading the status register, the current working status of the instrument can be obtained (such as whether it is outputting or triggering):

Operation status query: Status: Operation: CONDition? (Return 1 indicates normal operation, 0 indicates standby);

Event status query:: Status: EVENT: CONDition? (Return the event status code, such as 8 indicating trigger completion).

3. Debugging tools

Command echo: When enabled: SYSTem: ECHO ON, the instrument will return the received command for confirmation of whether the command was sent correctly;

Grammar check: Before sending a command, you can check the syntax using the command SYSTem: HECK: CMD (e.g. SYSTem: HECK: CMD ": SOURce: FREQ 1000");

Timeout setting: Set a timeout in the VISA library (recommended ≥ 1000ms) to avoid communication interruption caused by long command execution time (such as afg. timeout=2000).

Appendix Resources

Command index: a complete list of commands classified by "Source", "Trigger", and "System", including parameter descriptions and examples;

Example program: In addition to Python, it also provides control examples for C # and LabVIEW, covering scenarios such as waveform generation, modulation, and triggering;

VISA library compatibility: It explicitly supports TekVISA 4.0+and NI-VISA 5.0+, and it is not recommended to use older versions;

Firmware version description: Command differences between different firmware versions (such as some advanced commands requiring firmware ≥ 1.5.0).