2.3.6.6.1. Daisy chain generation and acquisition
2.3.6.6.1.1. Description
This example shows how to synchronise the Red Pitaya X-channel system (daisy chain) to simultaneously acquire 16k samples of a generated signal on multiple units (fast RF inputs and outputs).
2.3.6.6.1.2. Required hardware
Primary Red Pitaya device (STEMlab 125-14 LN)
One or more Secondary devices (STEMlab 125-14 LN Secondary)
SATA cables
SMA cables and SMA T-connectors
Wiring example:
Connect OUT1 of the primary device with IN1 of the primary device and IN1 of the secondary device.
Connect the Primary and Secondary devices with SATA cables
Pictures coming soon…
2.3.6.6.1.3. SCPI Code Examples
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).
2.3.6.6.1.3.1. Code - MATLAB
%% ### DAISY CHAIN EXAMPLE ###
% This example is for setting up two units (one primary and one secondary)
% For multiple secondary units duplicate the code for the secondary unit
% and change the IP address and RP_SEC to for example, RP_SECx (where x is
% a consecutive secondary unit)
% This example is written for the X-channel System connected with SATA cables
%% Parameters
clear all;
close all;
clc
% Generation
wave_form = 'SINE';
freq = 100e3;
ampl = 1;
% Acquisition
dec = 2;
trig_lvl = 0.5;
trig_dly = 7000;
%% Set up the IP and SCPI server
IP_PRI = 'rp-f066c8.local'; % Primary unit
IP_SEC = 'rp-f0ac90.local'; % Secondary unit
port = 5000;
RP_PRI = tcpclient(IP_PRI, port); % create a TCP client object
RP_SEC = tcpclient(IP_SEC, port);
RP_PRI.ByteOrder = 'big-endian'; % Define byte order and terminator for both units
configureTerminator(RP_PRI, 'CR/LF');
RP_SEC.ByteOrder = 'big-endian';
configureTerminator(RP_SEC, 'CR/LF'); % defines the line terminator (end sequence of input characters)
flush(RP_PRI);
fprintf('Program start');
%% Reseting Generation and Acquisition
writeline(RP_PRI,'GEN:RST');
writeline(RP_PRI,'ACQ:RST');
writeline(RP_SEC,'GEN:RST');
writeline(RP_SEC,'ACQ:RST');
%%% ENABLING THE DAISY CHAIN PRIMARY UNIT %%%
writeline(RP_PRI,'DAISY:SYNC:TRig ON');
writeline(RP_PRI,'DAISY:SYNC:CLK ON');
writeline(RP_PRI,'DAISY:TRIG_O:SOUR ADC'); % Select which trigger will be passed on over SATA
writeline(RP_PRI,'DIG:PIN LED5,1'); % indicator
fprintf('Trig: %s\n', writeread(RP_PRI,'DAISY:SYNC:TRig?'));
fprintf('CLK: %s\n', writeread(RP_PRI,'DAISY:SYNC:CLK?'));
fprintf('Source: %s\n', writeread(RP_PRI,'DAISY:TRIG_O:SOUR?'));
%%% ENABLING THE DAISY CHAIN SECONDARY UNIT %%%
% this section must be copied if using multiple secondary devices (once for each device)
writeline(RP_SEC,'DAISY:SYNC:TRig ON');
writeline(RP_SEC,'DAISY:SYNC:CLK ON');
writeline(RP_SEC,'DIG:PIN LED5,1'); % indicator
%% Generation - Primary unit
writeline(RP_PRI, append('SOUR1:FUNC ', wave_form));
writeline(RP_PRI, append('SOUR1:FREQ:FIX ', num2str(freq)));
writeline(RP_PRI, append('SOUR1:VOLT ', num2str(ampl)));
writeline(RP_PRI, 'OUTPUT1:STATE ON');
fprintf('Generation start\n');
%% Acquisition Setup
% Primary unit
writeline(RP_PRI, append('ACQ:DEC ', int2str(dec)));
writeline(RP_PRI, append('ACQ:TRig:LEV ', num2str(trig_lvl)));
writeline(RP_PRI, append('ACQ:TRig:DLY ', num2str(trig_dly)));
% Secondary unit
writeline(RP_SEC, append('ACQ:DEC ', num2str(dec)));
writeline(RP_SEC, append('ACQ:TRig:LEV ', num2str(trig_lvl)));
writeline(RP_SEC, append('ACQ:TRig:DLY ', num2str(trig_dly)));
%% Acquisition Start
fprintf('ACQ Start\n');
% First on secondary unit
writeline(RP_SEC, 'ACQ:START');
pause(0.05);
writeline(RP_SEC, 'ACQ:TRig EXT_NE');
% Then on primary unit
writeline(RP_PRI, 'ACQ:START');
pause(0.05);
writeline(RP_PRI, 'ACQ:TRig CH1_PE');
pause(0.1);
writeline(RP_PRI, 'SOUR1:TRig:INT'); % Simulate a trigger
% Acquisition check if data is ready
% ## Primary unit ##
while 1
% Get Trigger Status
trigger = writeread(RP_PRI, 'ACQ:TRig:STAT?');
if strcmp(trigger,'TD') % Triggerd?
break
end
end
fprintf('Trigger primary condition met.\n');
%%! OS 2.00 or higher only !%%
while 1
if strcmp(writeread(RP_PRI,'ACQ:TRig:FILL?'),'1')
break
end
end
fprintf('Buffer primary filled.\n');
% ## Secondary unit ##
while 1
% Get Trigger Status
if strcmp(writeread(RP_SEC,'ACQ:TRig:STAT?'),'TD') % Triggerd?
break
end
end
fprintf('Trigger secondary condition met.\n');
%%! OS 2.00 or higher only !%%
while 1
if strcmp(writeread(RP_SEC,'ACQ:TRig:FILL?'),'1')
break
end
end
fprintf('Buffer secondary filled.\n');
%% Read and plot data
data_string_pri = writeread(RP_PRI,'ACQ:SOUR1:DATA?');
data_string_sec = writeread(RP_SEC,'ACQ:SOUR1:DATA?');
% Convert values to numbers.
% The first character in string is “{“
% and the last 3 are 2 spaces and “}”.
data_pri = str2num(data_string_pri(1, 2:length(data_string_pri) - 3));
data_sec = str2num(data_string_sec(1, 2:length(data_string_sec) - 3));
% Plotting
x = 0:16383;
% MATLAB 2019b or higher
t = tiledlayout(2,1); % for MATLAB r2023a use 'vertical'
nexttile
plot(x, data_pri)
title('Primary unit data')
ylabel('V')
xlabel('Samples')
nexttile
plot(x,data_sec)
title('Secondary unit data')
ylabel('V')
xlabel('Samples')
title(t, 'Acquired data')
writeline(RP_PRI,'DIG:PIN LED5,0');
writeline(RP_SEC,'DIG:PIN LED5,0');
writeline(RP_PRI, 'OUTPUT1:STATE OFF');
clear RP_PRI RP_SEC;
2.3.6.6.1.3.2. Code - Python
Using just SCPI commands:
#!/usr/bin/env python3
"""Daisy chain example for Red Pitaya"""
import time
import matplotlib.pyplot as plt
import numpy as np
import redpitaya_scpi as scpi
# Connect OUT1 primary with IN1 primary and IN1 secondary
wave_form = "sine"
freq = 100000
ampl = 1
dec = 2
trig_lvl = 0.5
trig_dly = 7000
IP_PRIM = 'rp-f0a235.local' # IP Test OS Red Pitaya
IP_SEC = 'rp-f0ac90.local'
rp_prim = scpi.scpi(IP_PRIM)
rp_sec = scpi.scpi(IP_SEC)
print("Program Start")
rp_prim.tx_txt('GEN:RST')
rp_prim.tx_txt('ACQ:RST')
rp_sec.tx_txt('GEN:RST')
rp_sec.tx_txt('ACQ:RST')
###### ENABLING THE DAISY CHAIN PRIMARY UNIT ######
rp_prim.tx_txt('DAISY:SYNC:TRig ON') #! OFF (without sync)
rp_prim.tx_txt('DAISY:SYNC:CLK ON')
rp_prim.tx_txt('DAISY:TRIG_O:SOUR ADC')
rp_prim.tx_txt('DIG:PIN LED5,1') # LED Indicator
time.sleep(0.2)
print(f"Trig: {rp_prim.txrx_txt('DAISY:SYNC:TRig?')}")
print(f"CLK: {rp_prim.txrx_txt('DAISY:SYNC:CLK?')}")
print(f"Sour: {rp_prim.txrx_txt('DAISY:TRIG_O:SOUR?')}\n")
###### ENABLING THE DAISY CHAIN SECONDARY UNIT ######
rp_sec.tx_txt('DAISY:SYNC:TRig ON') #! OFF (without sync)
rp_sec.tx_txt('DAISY:SYNC:CLK ON')
rp_sec.tx_txt('DAISY:TRIG_O:SOUR ADC') # Ext trigger will trigger the ADC
rp_sec.tx_txt('DIG:PIN LED5,1') # LED Indicator
print("Start generator\n")
### Generation ### - Primary unit
rp_prim.tx_txt(f'SOUR1:FUNC {wave_form}')
rp_prim.tx_txt(f'SOUR1:FREQ:FIX {freq}')
rp_prim.tx_txt(f'SOUR1:VOLT {ampl}')
rp_prim.tx_txt('OUTPUT1:STATE ON')
### Aquisition ###
# Primary unit
rp_prim.tx_txt(f'ACQ:DEC {dec}')
rp_prim.tx_txt(f'ACQ:TRig:LEV {trig_lvl}')
rp_prim.tx_txt(f'ACQ:TRig:DLY {trig_dly}')
# Secondary unit
rp_sec.tx_txt(f'ACQ:DEC {dec}')
rp_sec.tx_txt(f'ACQ:TRig:LEV {trig_lvl}')
rp_sec.tx_txt(f'ACQ:TRig:DLY {trig_dly}')
rp_sec.tx_txt('ACQ:START')
time.sleep(0.2) # Not necessary
rp_sec.tx_txt('ACQ:TRig EXT_NE') #! CH1_PE (without sync trig) EXT_NE (with sync trig)
# If not synchronised make sure no signal arrives before both units are set up
rp_prim.tx_txt('ACQ:START')
time.sleep(0.2)
rp_prim.tx_txt('ACQ:TRig CH1_PE')
time.sleep(1) # Symulating a trigger after one second
rp_prim.tx_txt('SOUR1:TRig:INT')
print("ACQ start")
while 1:
# Get Trigger Status
if rp_prim.txrx_txt('ACQ:TRig:STAT?') == 'TD': # Triggerd?
break
print("Trigger primary condition met.")
## ! OS 2.00 or higher only ! ##
while 1:
if rp_prim.txrx_txt('ACQ:TRig:FILL?') == '1':
break
print("Buffer primary filled.")
while 1:
# Get Trigger Status
if rp_sec.txrx_txt('ACQ:TRig:STAT?') == 'TD': # Triggerd?
break
print("Trigger secondary condition met.")
## ! OS 2.00 or higher only ! ##
while 1:
if rp_sec.txrx_txt('ACQ:TRig:FILL?') == '1':
break
print("Buffer secondary filled.")
# Read data and plot
rp_prim.tx_txt('ACQ:SOUR1:DATA?') # Read full buffer primary (source 1)
data_string1 = rp_prim.rx_txt() # data into a string
rp_sec.tx_txt('ACQ:SOUR1:DATA?') # Read full buffer secondary (source 1)
data_string2 = rp_sec.rx_txt()
# Display both buffers at once
n = 2
buff = np.zeros((n,16384))
# Remove brackets and empty spaces + string => float
data_string1 = data_string1.strip('{}\n\r').replace(" ", "").split(',')
data_string2 = data_string2.strip('{}\n\r').replace(" ", "").split(',')
# Transform data into data series
buff[0, :] = list(map(float, data_string1))
buff[1, :] = list(map(float, data_string2))
######## PLOTTING THE DATA #########
fig, axs = plt.subplots(n, sharex = True) # plot the data (n subplots)
fig.suptitle("Measurements P1 S2")
for i in range(0,n,1): # plotting the acquired buffers
axs[i].plot(buff[i])
plt.show()
rp_prim.close()
rp_sec.close()
Using functions:
#!/usr/bin/env python3
"""Daisy chain example for Red Pitaya"""
import time
import matplotlib.pyplot as plt
import numpy as np
import redpitaya_scpi as scpi
# Connect OUT1 primary with IN1 primary and IN1 secondary
IP_PRIM = 'rp-f0a235.local' # IP Test OS Red Pitaya
IP_SEC = 'rp-f0ac90.local'
rp_prim = scpi.scpi(IP_PRIM)
rp_sec = scpi.scpi(IP_SEC)
print("Program Start")
rp_prim.tx_txt('GEN:RST')
rp_prim.tx_txt('ACQ:RST')
rp_sec.tx_txt('GEN:RST')
rp_sec.tx_txt('ACQ:RST')
###### ENABLING THE DAISY CHAIN PRIMARY UNIT ######
rp_prim.tx_txt('DAISY:SYNC:TRig ON') #! OFF (without sync)
rp_prim.tx_txt('DAISY:SYNC:CLK ON')
rp_prim.tx_txt('DAISY:TRIG_O:SOUR ADC')
rp_prim.tx_txt('DIG:PIN LED5,1') # LED Indicator
time.sleep(0.2)
print(f"Trig: {rp_prim.txrx_txt('DAISY:SYNC:TRig?')}")
print(f"CLK: {rp_prim.txrx_txt('DAISY:SYNC:CLK?')}")
print(f"Sour: {rp_prim.txrx_txt('DAISY:TRIG_O:SOUR?')}\n")
###### ENABLING THE DAISY CHAIN SECONDARY UNIT ######
rp_sec.tx_txt('DAISY:SYNC:TRig ON') #! OFF (without sync)
rp_sec.tx_txt('DAISY:SYNC:CLK ON')
rp_sec.tx_txt('DAISY:TRIG_O:SOUR ADC') # Ext trigger will trigger the ADC
rp_sec.tx_txt('DIG:PIN LED5,1') # LED Indicator
print("Start generator\n")
### Generation ### - Primary unit
rp_prim.sour_set(1, "sine", 1, 100000)
rp_prim.tx_txt('OUTPUT1:STATE ON')
### Aquisition ###
# Primary unit
rp_prim.acq_set(dec = 2,
trig_lvl = 0.5,
trig_delay = 7000)
# Secondary unit
rp_sec.acq_set(dec = 2,
trig_lvl = 0.5,
trig_delay = 7000)
rp_sec.tx_txt('ACQ:START')
time.sleep(0.2) # Not necessary
rp_sec.tx_txt('ACQ:TRig EXT_NE') #! CH1_PE (without sync trig) EXT_NE (with sync trig)
# If not synchronised make sure no signal arrives before both units are set up
rp_prim.tx_txt('ACQ:START')
time.sleep(0.2)
rp_prim.tx_txt('ACQ:TRig CH1_PE')
time.sleep(1) # Symulating a trigger after one second
rp_prim.tx_txt('SOUR1:TRig:INT')
print("ACQ start")
while 1:
# Get Trigger Status
if rp_prim.txrx_txt('ACQ:TRig:STAT?') == 'TD': # Triggerd?
break
print("Trigger primary condition met.")
## ! OS 2.00 or higher only ! ##
while 1:
if rp_prim.txrx_txt('ACQ:TRig:FILL?') == '1':
break
print("Buffer primary filled.")
while 1:
# Get Trigger Status
if rp_sec.txrx_txt('ACQ:TRig:STAT?') == 'TD': # Triggerd?
break
print("Trigger secondary condition met.")
## ! OS 2.00 or higher only ! ##
while 1:
if rp_sec.txrx_txt('ACQ:TRig:FILL?') == '1':
break
print("Buffer secondary filled.")
# Read data and plot
rp_prim.tx_txt('ACQ:SOUR1:DATA?') # Read full buffer primary (source 1)
data_string1 = rp_prim.rx_txt() # data into a string
rp_sec.tx_txt('ACQ:SOUR1:DATA?') # Read full buffer secondary (source 1)
data_string2 = rp_sec.rx_txt()
# Display both buffers at once
n = 2
buff = np.zeros((n,16384))
# Remove brackets and empty spaces + string => float
data_string1 = data_string1.strip('{}\n\r').replace(" ", "").split(',')
data_string2 = data_string2.strip('{}\n\r').replace(" ", "").split(',')
# Transform data into data series
buff[0, :] = list(map(float, data_string1))
buff[1, :] = list(map(float, data_string2))
######## PLOTTING THE DATA #########
fig, axs = plt.subplots(n, sharex = True) # plot the data (n subplots)
fig.suptitle("Measurements P1 S2")
for i in range(0,n,1): # plotting the acquired buffers
axs[i].plot(buff[i])
plt.show()
rp_prim.close()
rp_sec.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.
2.3.6.6.1.4. 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.
2.3.6.6.1.4.1. Code - Python API
#!/usr/bin/python3
import time
import numpy as np
import rp
########! Primary unit code !#########
channel = rp.RP_CH_1 # rp.RP_CH_2
waveform = rp.RP_WAVEFORM_SINE
freq = 100000
ampl = 1.0
trig_lvl = 0.5
trig_dly = 0
dec = rp.RP_DEC_1
gen_trig_sour = rp.RP_GEN_TRIG_SRC_INTERNAL
acq_trig_sour = rp.RP_TRIG_SRC_CHA_PE
N = 16384
# Initialize the interface
rp.rp_Init()
# Reset Generation and Acquisition
rp.rp_GenReset()
rp.rp_AcqReset()
###### Enable Daisy Chain #####
rp.rp_SetEnableDiasyChainClockSync(True) # Sync Clock
rp.rp_SetEnableDaisyChainTrigSync(True) # Sync Trigger
# Choose which trigger to synchronise (rp.OUT_TR_ADC, rp.OUT_TR_DAC)
rp.rp_SetSourceTrigOutput(rp.OUT_TR_ADC)
# LED indicator
rp.rp_DpinSetState(rp.RP_LED5, rp.RP_HIGH)
###### Generation #####
print("Gen_start")
rp.rp_GenWaveform(channel, waveform)
rp.rp_GenFreqDirect(channel, freq)
rp.rp_GenAmp(channel, ampl)
rp.rp_GenTriggerSource(channel, gen_trig_sour)
rp.rp_GenOutEnable(channel)
##### Acquisition #####
rp.rp_AcqSetDecimation(dec)
# Set trigger level and delay
rp.rp_AcqSetTriggerLevel(rp.RP_T_CH_1, trig_lvl)
rp.rp_AcqSetTriggerDelay(trig_dly)
# Start Acquisition
print("Acq_start")
rp.rp_AcqStart()
# Specify trigger - input 1 positive edge
rp.rp_AcqSetTriggerSrc(acq_trig_sour)
rp.rp_GenTriggerOnly(channel) # Trigger generator
# Trigger state
while 1:
trig_state = rp.rp_AcqGetTriggerState()[1]
if trig_state == rp.RP_TRIG_STATE_TRIGGERED:
break
## ! OS 2.00 or higher only ! ##
# Fill state
while 1:
if rp.rp_AcqGetBufferFillState()[1]:
break
### Get data ###
# Volts
fbuff = rp.fBuffer(N)
res = rp.rp_AcqGetDataV(rp.RP_CH_1, 0, N, fbuff)
data_V = np.zeros(N, dtype = float)
for i in range(0, N, 1):
data_V[i] = fbuff[i]
print(f"Data in Volts: {data_V}")
# Release resources
rp.rp_Release()
########! Secondary unit code !#########
channel = rp.RP_CH_1 # rp.RP_CH_2
waveform = rp.RP_WAVEFORM_SINE
freq = 100000
ampl = 1.0
trig_lvl = 0.5
trig_dly = 0
dec = rp.RP_DEC_1
# Initialize the interface
rp.rp_Init()
# Reset Generation and Acquisition
rp.rp_GenReset()
rp.rp_AcqReset()
###### Enable Daisy Chain #####
rp.rp_SetEnableDiasyChainClockSync(True) # Sync Clock
rp.rp_SetEnableDaisyChainTrigSync(True) # Sync Trigger
# Choose which trigger to synchronise (rp.OUT_TR_ADC, rp.OUT_TR_DAC)
rp.rp_SetSourceTrigOutput(rp.OUT_TR_ADC)
# LED indicator
rp.rp_DpinSetState(rp.RP_LED5, rp.RP_HIGH)
##### Acquisition #####
rp.rp_AcqSetDecimation(dec)
rp.rp_AcqSetTriggerDelay(trig_dly)
# Start Acquisition
print("Acq_start")
rp.rp_AcqStart()
# Specify trigger - must be EXT_NE
rp.rp_AcqSetTriggerSrc(rp.RP_TRIG_SRC_EXT_NE)
# Trigger state
while 1:
trig_state = rp.rp_AcqGetTriggerState()[1]
if trig_state == rp.RP_TRIG_STATE_TRIGGERED:
break
## ! OS 2.00 or higher only ! ##
# Fill state
while 1:
if rp.rp_AcqGetBufferFillState()[1]:
break
### Get data ###
# Volts
fbuff = rp.fBuffer(N)
res = rp.rp_AcqGetDataV(rp.RP_CH_1, 0, N, fbuff)
data_V = np.zeros(N, dtype = float)
for i in range(0, N, 1):
data_V[i] = fbuff[i]
print(f"Data in Volts: {data_V}")
# Release resources
rp.rp_Release()