Generate two synchronous signals

Description

This example shows how to program Red Pitaya to generate two synchronous analog signals. Voltage and frequency ranges depend on the Red Pitaya model.

Required hardware

Red Pitaya device

Required software

2.00-23 or higher OS

Note

This code is written for 2.00-23 or higher OS. For older OS versions, please check when specific commands were released (a note is added to each command introduced in 2.00 or higher verisons).

SCPI Code Examples

Code - MATLAB®

The code is written in MATLAB. TCP client communication is used to establish socket communication with Red Pitaya, then SCPI commands are sent to configure the various Red Pitaya peripherals. Copy the code below into the MATLAB editor, save the project and press the Run button. Tested on MATLAB 2024b.

%% Define Red Pitaya as TCP/IP object
clc
close all

IP = 'rp-f0a235.local';            % Input IP of your Red Pitaya...
port = 5000;
RP = tcpclient(IP, port);

%% Open connection with your Red Pitaya
RP.ByteOrder = 'big-endian';
configureTerminator(RP, 'CR/LF');

waveform = 'sine';                  % {sine, square, triangle, sawu, sawd, pwm}
freq = 1000;
ampl = 1;
waveform2 = 'triangle';                  % {sine, square, triangle, sawu, sawd, pwm}
freq2 = 2000;
ampl2 = 0.5;

writeline(RP,'GEN:RST');
writeline(RP, append('SOUR1:FUNC ', waveform));
writeline(RP, append('SOUR1:FREQ:FIX ', num2str(freq)));
writeline(RP, append('SOUR1:VOLT ', num2str(ampl)));

writeline(RP, append('SOUR2:FUNC ', waveform2));
writeline(RP, append('SOUR2:FREQ:FIX ', num2str(freq2)));
writeline(RP, append('SOUR2:VOLT ', num2str(ampl2)));

writeline(RP,'OUTPUT:STATE ON');       % Start two channels simultaneously
writeline(RP,'SOUR:TRig:INT');

%% Close connection with Red Pitaya
clear RP;

Code - Python

Using SCPI commands:

#!/usr/bin/env python3

import sys
import redpitaya_scpi as scpi

rp = scpi.scpi("192.168.1.17")

wave_form = 'sine'
freq = 2000
ampl = 1

rp.tx_txt('GEN:RST')

rp.tx_txt('SOUR1:FUNC ' + str(wave_form).upper())
rp.tx_txt('SOUR1:FREQ:FIX ' + str(freq))
rp.tx_txt('SOUR1:VOLT ' + str(ampl))
rp.tx_txt('SOUR2:FUNC ' + str(wave_form).upper())
rp.tx_txt('SOUR2:FREQ:FIX ' + str(freq))
rp.tx_txt('SOUR2:VOLT ' + str(ampl))

rp.tx_txt('OUTPUT:STATE ON')
rp.tx_txt('SOUR:TRig:INT')

rp.close()

Using functions:

#!/usr/bin/env python3

import sys
import redpitaya_scpi as scpi

rp = scpi.scpi("192.168.1.17")

wave_form = 'sine'
freq = 2000
ampl = 1

rp.tx_txt('GEN:RST')

# Function for configuring a Source
rp.sour_set(1, wave_form, ampl, freq)
rp.sour_set(2, wave_form, ampl, freq)

rp.tx_txt('OUTPUT:STATE ON')
rp.tx_txt('SOUR:TRig:INT')

rp.close()

Note

The Python functions are accessible with the latest version of the redpitaya_scpi.py document available on our GitHub. The functions represent a quality-of-life improvement as they combine the SCPI commands in an optimal order and also check for improper user inputs. The code should function at approximately the same speed without them.

For further information on functions please consult the redpitaya_scpi.py code.

API Code Examples

Note

The API code examples don’t require the use of the SCPI server. Instead, the code should be compiled and executed on the Red Pitaya itself (inside Linux OS). Instructions on how to compile the code and other useful information are here.

Code - C++ API

/* Red Pitaya C++ API example of Generating Synced signals */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "rp.h"

int main(int argc, char **argv){

    /* Print error, if rp_Init() function failed */
    if(rp_Init() != RP_OK){
        fprintf(stderr, "Rp api init failed!\n");
    }

    /* Reset Generation and */
    rp_GenReset();

    /* Generation */
    rp_GenSynchronise();

    rp_GenWaveform(RP_CH_1, RP_WAVEFORM_SINE);
    rp_GenFreq(RP_CH_1, 2000);
    rp_GenAmp(RP_CH_1, 1);

    rp_GenWaveform(RP_CH_2, RP_WAVEFORM_SINE);
    rp_GenFreq(RP_CH_2, 2000);
    rp_GenAmp(RP_CH_2, 1);

    rp_GenOutEnableSync(true);
    rp.rp_GenSynchronise()

    /* Release rp resources */
    rp_Release();
    return 0;
}

Code - Python API

#!/usr/bin/python3

import time
import numpy as np
import rp

#? Possible waveforms:
#?   RP_WAVEFORM_SINE, RP_WAVEFORM_SQUARE, RP_WAVEFORM_TRIANGLE, RP_WAVEFORM_RAMP_UP,
#?   RP_WAVEFORM_RAMP_DOWN, RP_WAVEFORM_DC, RP_WAVEFORM_PWM, RP_WAVEFORM_ARBITRARY,
#?   RP_WAVEFORM_DC_NEG, RP_WAVEFORM_SWEEP

channel = rp.RP_CH_1        # rp.RP_CH_2
channel2 = rp.RP_CH_2
waveform = rp.RP_WAVEFORM_SINE
freq = 10000
ampl = 1

#? Possible trigger sources:
#?   RP_GEN_TRIG_SRC_INTERNAL, RP_GEN_TRIG_SRC_EXT_PE, RP_GEN_TRIG_SRC_EXT_NE
gen_trig_sour = rp.RP_GEN_TRIG_SRC_INTERNAL

# Initialize the interface
rp.rp_Init()

# Reset generator
rp.rp_GenReset()

###### Generation #####
# OUT1
rp.rp_GenWaveform(channel, waveform)
rp.rp_GenFreqDirect(channel, freq)
rp.rp_GenAmp(channel, ampl)

# OUT2
rp.rp_GenWaveform(channel2, waveform)
rp.rp_GenFreqDirect(channel2, freq)
rp.rp_GenAmp(channel2, ampl)

# Specify generator trigger source
rp.rp_GenTriggerSource(channel, gen_trig_sour)

# Enable output synchronisation
rp.rp_GenOutEnableSync(True)

# Syncronise output channels
rp.rp_GenSynchronise()

# Release resources
rp.rp_Release()