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"""
Provide basic class to operate scope
Created by Eugeniy E. Mikhailov 2021/11/29
"""
import pyvisa
import scpi
import re
import numpy as np
class Scope(scpi.SCPIinstr):
"""
Do not instantiate directly, use
rm = pyvisa.ResourceManager()
Scope(rm.open_resource('TCPIP::192.168.0.2::INSTR'))
"""
def __init__(self, resource):
super().__init__(resource)
class SDS1104x(Scope):
""" Siglent SDS1104x scope """
def __init__(self, resource):
super().__init__(resource)
self.resource.read_termination='\n'
self.maxRequiredPoints = 1000; # desired number of points per channel, can return twice more
def response2numStr(self, strIn, firstSeparator=None, unit=None):
# A typical reply of Siglent is in the form 'TDIV 2.00E-08S'
# i.e. "<prefix><firstSeparator><numberString><unit>
# prefix='TDIV', firstSeparator=' ', numberString='2.00E-08', unit='S'
# this function parses the reply
spltStr = re.split(firstSeparator, strIn)
prefix = spltStr[0]
rstr = spltStr[1]
spltStr = re.split(unit, rstr)
numberString = spltStr[0]
unit = spltStr[1]
return (prefix, numberString, unit)
def mean(self, chNum):
# get mean on a specific channel calculated by scope
# PAVA stands for PArameter VAlue
qstr = f'C{chNum}:PAVA? MEAN'
rstr = self.query(qstr);
# reply is in the form 'C1:PAVA MEAN,3.00E-02V'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=',', unit='V')
return(float(numberString))
def getAvailableNumberOfPoints(self, chNum):
if chNum != 1 and chNum != 3:
# for whatever reason 'SAMPLE_NUM' fails for channel 2 and 4
chNum = 1
qstr = f'SAMPLE_NUM? C{chNum}'
rstr = self.query(qstr)
# reply is in the form 'SANU 7.00E+01pts'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='pts')
return(int(float(numberString)))
def getSampleRate(self):
rstr = self.query('SAMPLE_RATE?');
# expected reply is like 'SARA 1.00E+09Sa/s'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='Sa/s')
return(int(float(numberString)))
def getRawWaveform(self, chNum, availableNpnts=None, maxRequiredPoints=None):
if availableNpnts == None:
availableNpnts = self.getAvailableNumberOfPoints(chNum)
if maxRequiredPoints == None:
maxRequiredPoints = self.maxRequiredPoints
if availableNpnts <= maxRequiredPoints*2:
Npnts = availableNpnts
sparsing = 1
cstr = f'WAVEFORM_SETUP NP,0,FP,0,SP,{sparsing}'
self.write(cstr)
else:
sparsing = int(np.floor(availableNpnts/maxRequiredPoints))
Npnts = int(np.floor(availableNpnts/sparsing))
cstr = f'WAVEFORM_SETUP SP,{sparsing},NP,{Npnts},FP,0'
# Note: it is not enough to provide sparsing (SP),
# number of points (NP) needed to be calculated properly too!
# From the manual
# WAVEFORM_SETUP SP,<sparsing>,NP,<number>,FP,<point>
# SP Sparse point. It defines the interval between data points.
# For example:
# SP = 0 sends all data points.
# SP = 1 sends all data points.
# SP = 4 sends every 4th data point
# NP — Number of points. It indicates how many points should be transmitted.
# For example:
# NP = 0 sends all data points.
# NP = 50 sends a maximum of 50 data points.
# FP — First point. It specifies the address of the first data point to be sent.
# For example:
# FP = 0 corresponds to the first data point.
# FP = 1 corresponds to the second data point
qstr = f'C{chNum}:WAVEFORM? DAT2'
wfRaw=self.query_binary_values(qstr, datatype='b', header_fmt='ieee', container=np.array)
# expected full reply: 'C1:WF DAT2,#9000000140.........'
return(wfRaw, availableNpnts, sparsing)
def getChanVoltsPerDiv(self, chNum):
qstr = f'C{chNum}:VDIV?'
rstr = self.query(qstr)
# expected reply to query: 'C1:VDIV 1.04E+00V'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='V')
return(float(numberString))
def getChanOffset(self, chNum):
qstr = f'C{chNum}:OFST?'
rstr = self.query(qstr)
# expected reply to query: 'C1:OFST -1.27E+00V'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='V')
return(float(numberString))
def getTimePerDiv(self):
qstr = f'TDIV?'
rstr = self.query(qstr)
# expected reply to query: 'TDIV 2.00E-08S'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='S')
return(float(numberString))
def getTrigDelay(self):
qstr = f'TRIG_DELAY?'
rstr = self.query(qstr)
# expected reply to query: 'TRDL -0.00E+00S'
prefix, numberString, unit = self.response2numStr(rstr, firstSeparator=' ', unit='S')
return(float(numberString))
def getWaveform(self, chNum, availableNpnts=None, maxRequiredPoints=None):
wfRaw, availableNpnts, sparsing = self.getRawWaveform(chNum, availableNpnts=availableNpnts, maxRequiredPoints=maxRequiredPoints)
vertDivOnScreen = 10
VoltageOffset = self.getChanOffset(chNum)
VoltsPerDiv = self.getChanVoltsPerDiv(chNum)
return( wfRaw * VoltsPerDiv * vertDivOnScreen/250 -VoltageOffset, availableNpnts, sparsing)
def getTimeTrace(self, sparsing=1, Npnts=None):
sampleRate = self.getSampleRate()
timePerDiv = self.getTimePerDiv()
trigDelay = self.getTrigDelay()
if Npnts == None:
# using channel 1 as reference
Npnts = self.getAvailableNumberOfPoints(1)
time = np.arange(Npnts) / sampleRate * sparsing;
horizDivOnScreen = 14
time = time - timePerDiv * horizDivOnScreen/2 - trigDelay
return(time)
if __name__ == '__main__':
print("testing")
rm = pyvisa.ResourceManager()
print(rm.list_resources())
instr=rm.open_resource('TCPIP::192.168.0.61::INSTR')
scope = SDS1104x(instr)
print(scope.idn)
print(scope.mean(1))
print(scope.getAvailableNumberOfPoints(1))
print(scope.getSampleRate())
print(scope.getTimePerDiv())
print(scope.getChanVoltsPerDiv(1))
print(scope.getChanOffset(1))
wf = scope.getWaveform(4)
time = scope.getTimeTrace()
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