3.4.6.6.2. Synchronised Click Shield Generation and Acquisition
3.4.6.6.2.1. Description
This example shows how to synchronise multiple Red Pitaya boards to simultaneously acquire 16k samples of a generated signal on multiple Red Pitaya units (fast RF inputs and outputs) using the Red Pitaya Click Shields. Red Pitaya can transmit the trigger signal through the DIO0_N and receive it on DIO0_P.
This example can be easily modified for simultaneous generation (setup the signal generation, choose a primary trigger, all secondary triggers set to EXT_NE, and finally, change the daisy trigger source to DAC).
3.4.6.6.2.2. Required hardware
Two or more Red Pitaya External clock devices (STEMlab 125-14 Ext. clk., SDRlab 122-16 Ext. Clk., STEMlab 125-14 4-Input)
A Red Pitaya Click Shield for each unit
U.FL Cables
SMA cables
SMA T-connectors
Note
STEMlab 125-14 4-Input has a Clock Select pin to determine whether the clock should be internal or external. For more information, see STEMlab 125-14 4-Input documentation.
3.4.6.6.2.3. Required software
2.04-35 or higher OS
Note
This code is written for 2.04-35 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).
3.4.6.6.2.4. Wiring example
The Red Pitaya Click Shield can synchronise multiple Red Pitaya units together. As U.FL cables are used for clock and trigger synchronisation, other external clock devices can also be included in the chain. The connection provides minimal clock signal delay between multiple Red Pitaya units, as there is only a single ZL40213 LVDS clock fanout buffer between two units.
To synchronise two or more Red Pitaya units, establish the following connections with U.FL cables between the primary board (transmitting clock and trigger signals) and the secondary board (receiving the clock and trigger signals). Use one of the two schemes depending on whether you want to connect an external clock or use the oscillator on the Red Pitaya Click Shields.
3.4.6.6.2.4.1. Oscillator
When using the oscillator, the first Red Pitaya Click Shield transmits the clock and trigger signals to all devices in the chain. Here are the most important things to check:
Primary board:
Jumpers J4 and J5 connected. Connect the oscillator to the clocking transmission line.
Jumpers J6 and J7 connected. Connect the Red Pitaya trigger to the trigger transmission line.
Jumper J1 disconnected (unless using a single wire clock).
CLK OSC switch in ON position.
CLK SELECT switch in EXT position.
Secondary board:
Jumper J6 connected. Connect the trigger to the Ext. Trigger pin.
Jumper J1 disconnected (unless using a single wire clock).
CLK OSC switch in OFF position.
CLK SELECT switch in EXT position.
If an external trigger signal is used, copy the secondary board’s trigger connections to the primary board (disconnect J7 and connect the external trigger U.FL cable). Otherwise, DIO0_N acts as external trigger output (on the primary board), and DIO0_P acts as external trigger input.
3.4.6.6.2.4.2. External Clock
When using an external clock and external trigger, the clock and trigger signals are transmitted to all devices in the chain. All the Click Shields share the same configuration:
Primary and Secondary boards:
Jumper J6 connected. Connect the trigger to the Ext. Trigger pin.
Jumper J1 disconnected (unless using a single wire clock).
CLK OSC switch in OFF position.
CLK SELECT switch in EXT position.
Note
For more information on connectors, switches, and jumper positions, check out the Red Pitaya Click Shield documentation.
Note
The trigger signals from the SATA connector and the DIO0_P (External trigger pin) are OR-ed together in the software. The generation and acquisition trigger fronts apply after the “OR gate” and trigger either DAC or ADC, depending on the DAISY:TRIG_O:SOUR <mode> command.
3.4.6.6.2.5. SCPI Code Examples
3.4.6.6.2.5.1. Code - MATLAB®
%% ### CLICK SHIELD 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 for External clock Red Pitaya units connected with Red
% Pitaya Click Shields
%% 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');
%%% PRIMARY UNIT %%%
writeline(RP_PRI,'DAISY:TRig:Out:ENable ON');
writeline(RP_PRI,'DAISY:TRig:Out:SOUR ADC'); % Select which trigger will be shared
writeline(RP_PRI,'DIG:PIN LED5,1'); % indicator
fprintf('DIO0_N trigger: %s\n', writeread(RP_PRI,'DAISY:TRig:Out:ENable?'));
fprintf('Trigger source: %s\n', writeread(RP_PRI,'DAISY:TRig:Out:SOUR?'));
%%% SECONDARY UNIT %%%
% this section must be copied if using multiple secondary devices (once for each device)
writeline(RP_PRI,'DAISY:TRig:Out:ENable OFF');
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:Factor ', 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:Factor ', 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');
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');
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');
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;
3.4.6.6.2.5.2. Code - Python
Using SCPI commands:
#!/usr/bin/env python3
""" Click shield 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' # Red Pitaya IP
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:TRig:Out:ENable ON') # Enables DIO0_N as trigger output
rp_prim.tx_txt('DAISY:TRig:Out:SOUR ADC') # Ext trigger will trigger the ADC
rp_prim.tx_txt('DIG:PIN LED5,1') # LED Indicator
time.sleep(0.2)
print(f"DIO0_N trig: {rp_prim.txrx_txt('DAISY:TRig:Out:ENable?')}\n")
print(f"Trig source: {rp_prim.txrx_txt('DAISY:TRig:Out:SOUR?')}\n")
###### ENABLING THE DAISY CHAIN SECONDARY UNIT ######
rp_sec.tx_txt('DAISY:TRig:Out:ENable OFF') # Disables DIO0_N as trigger output
rp_sec.tx_txt('DAISY:TRig:Out: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:Factor {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:Factor {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')
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.")
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.")
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
""" Click shield 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' # Red Pitaya IP
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:TRig:Out:ENable ON') # Enables DIO0_N as trigger output
rp_prim.tx_txt('DAISY:TRig:Out:SOUR ADC') # Ext trigger will trigger the ADC
rp_prim.tx_txt('DIG:PIN LED5,1') # LED Indicator
time.sleep(0.2)
print(f"DIO0_N trig: {rp_prim.txrx_txt('DAISY:TRig:Out:ENable?')}\n")
print(f"Trig source: {rp_prim.txrx_txt('DAISY:TRig:Out:SOUR?')}\n")
###### ENABLING THE DAISY CHAIN SECONDARY UNIT ######
rp_sec.tx_txt('DAISY:TRig:Out:ENable OFF') # Disables DIO0_N as trigger output
rp_sec.tx_txt('DAISY:TRig:Out: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')
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.")
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.")
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.
3.4.6.6.2.6. 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.
3.4.6.6.2.6.1. 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_SetDpinEnableTrigOutput(True) # Enable trigger output on DIO0_N
# 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
# 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_SetDpinEnableTrigOutput(False) # Disable trigger output on DIO0_N
# 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
while 1:
if rp.rp_AcqGetBufferFillState()[1]:
break
### Get data ###
# Volts
fbuff = rp.fBuffer(N)
res = rp.rp_AcqGetDataVNP(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()