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"""
Created by Eugeniy E. Mikhailov 2021/11/29
"""
from qolab.hardware.scope.sds1104x import SDS1104X
from qolab.hardware.scope._basic import calcSparsingAndNumPoints
from qolab.hardware.basic import BasicInstrument
from qolab.hardware.scpi import response2numStr
from qolab.data.trace import Trace
import numpy as np
import scipy.signal
from pyvisa.constants import InterfaceType
class SDS800XHD(SDS1104X):
"""Siglent SDS800XHD scope"""
# SDS1104x has actually 8 divisions but its behave like it has 10,
# the grabbed trace has more points outside what is visible on the screen
vertDivOnScreen = 8
horizDivOnScreen = 10
def __init__(self, resource, *args, **kwds):
super().__init__(resource, *args, **kwds)
self.config["Device model"] = "SDS800XHD"
self.resource.read_termination = "\n"
self.resource.timeout = 1000
self.numberOfChannels = 4
self.maxRequiredPoints = 1000
# desired number of points per channel, can return twice more
@BasicInstrument.tsdb_append
def getTimePerDiv(self):
qstr = "TDIV?"
rstr = self.query(qstr)
# Careful! TDIV? is undocumented for SDS800XHD scope,
# the prescribe command is ":TIMebase:SCALe?".
# But "TDIV?" works identical to SDS2304, i.e.
# Siglent claims that this model should have same commands as SDS1104X
# However response is different.
# For example we got '2.00E-08S' instead 'TDIV 2.00E-08S'
# expected reply to query: '2.00E-08S'
prefix, numberString, unit = response2numStr(
rstr, firstSeparator=None, unit="S"
)
return float(numberString)
def getRawWaveform(
self, chNum, availableNpnts=None, maxRequiredPoints=None, decimate=True
):
"""
Get raw channel waveform in binary format.
Parameters
----------
chNum : int
Scope channel to use: 1, 2, 3, or 4
availableNpnts : int or None (default)
Available number of points. Do not set it if you want it auto detected.
maxRequiredPoints : int
Maximum number of required points, if we ask less than available
we well get sparse set which proportionally fills all available time range.
decimate : False or True (default)
Decimate should be read as apply the low pass filter or not, technically
for both setting we get decimation (i.e. smaller than available
at the scope number of points). The name came from
``scipy.signal.decimate`` filtering function.
If ``decimate=True`` is used, we get all available points
and then low-pass filter them to get ``maxRequiredPoints``
The result is less noisy then, but transfer time from the instrument
is longer.
If ``decimate=False``, then it we are skipping points to get needed number
but we might see aliasing, if there is a high frequency noise
and sparing > 1. Unless you know what you doing, it is recommended
to use ``decimate=True``.
"""
rawChanCfg = {}
# switching to binary data transfer
self.write(":WAVeform:WIDTh WORD") # two bytes per data point
rawChanCfg["WaveformWidth"] = "WORD"
self.write(":WAVeform:BYTeorder LSB")
rawChanCfg["WaveformByteorder"] = "LSB"
if availableNpnts is None:
# using channel 1 to get availableNpnts
availableNpnts = self.getAvailableNumberOfPoints(1)
rawChanCfg["availableNpnts"] = availableNpnts
if maxRequiredPoints is None:
maxRequiredPoints = self.maxRequiredPoints
(
sparsing,
Npnts,
availableNpnts,
maxRequiredPoints,
) = calcSparsingAndNumPoints(availableNpnts, maxRequiredPoints)
rawChanCfg["Npnts"] = Npnts
rawChanCfg["sparsing"] = sparsing
if decimate:
Npnts = availableNpnts # get all of them and decimate later
if (sparsing == 1 and Npnts == availableNpnts) or decimate:
# We are getting all points of the trace
self.write(":WAVeform:STARt 0") # start point to read from the scope memory
self.write(f":WAVeform:MAXPoint {availableNpnts}") # last point to read
self.write(":WAVeform:INTerval 1") # sparsing of 1, i.e. read every point
self.write(f":WAVeform:POINt {availableNpnts}") # transfer all points
else:
# we just ask every point with 'sparsing' interval
# fast to grab but we could do better with more advance decimate
# method, which allow better precision for the price
# of longer acquisition time
self.write(":WAVeform:STARt 0") # start point to read from the scope memory
self.write(f":WAVeform:MAXPoint {availableNpnts}") # last point to read
self.write(f":WAVeform:INTerval {sparsing}") # interval between points
# Note: it is not enough to provide sparsing
# number of requested points needed to be asked too.
# However this scope is smart enough to truncate the output to
# physically available points, if you request more no harm is done.
self.write(f":WAVeform:POINt {Npnts}") # transfer all points
trRaw = Trace(f"Ch{chNum}")
self.write(":WAVeform:SOURce C{chNum}")
qstr = f":WAVeform:DATA?"
if self.resource.interface_type == InterfaceType.usb:
# Setting chunk size to 496 bytes, it seems that SDS sends data
# in 512 bytes chunks via USB.
# Which is 8 packets of 64 bytes, but each packet takes 2 bytes for a header.
# Thus useful payload is 512-8*2 = 496
# see https://patchwork.ozlabs.org/project/qemu-devel/patch/20200317095049.28486-4-kraxel@redhat.com/
# Setting chunk_size for a large number has *catastrophic* results
# on data transfer rate, since we wait for more data
# which is not going to come until timeout expires
# Setting it low is not as bad but still slows down the transfer.
# NOTE: I am not sure if it is a Linux driver issue or more global.
# The transfer rate is about
# 5550 kB/S, for 10k points
# 1400 kB/S, for 50k points
# 1000 kB/S, for 100k points
# 500 kB/S, for 500k points
# 160 kB/S, for 1000k points
# 55 kB/S, for 2.5M points
# It is about factor of 2 slower (for 100k points),
# if the scope is in the Run mode, i.e. not Stopped.
# FIXME find why speed depends on number of points.
wfRaw = self.query_binary_values(
qstr,
datatype="h",
header_fmt="ieee",
container=np.array,
chunk_size=496,
)
else:
wfRaw = self.query_binary_values(
qstr, datatype="h", header_fmt="ieee", container=np.array
)
trRaw.values = wfRaw.reshape(wfRaw.size, 1)
if decimate and sparsing != 1:
numtaps = 3
# not sure it is the best case
trRaw.values = scipy.signal.decimate(
trRaw.values, sparsing, numtaps, axis=0
)
trRaw.config["unit"] = "Count"
trRaw.config["tags"]["Decimate"] = decimate
trRaw.config["tags"]["rawChanConfig"] = rawChanCfg
return trRaw
def getParsedPreamble(self):
"""
Parse preamble generated by the scope.
It has a lot of information, number of points, scale, bits resolution, etc.
Note: preamble is channel specific! The prior code must set desired channel
with self.write(":WAVeform:SOURce C{chNum}")
"""
preamble = {}
qstr = ":WAVeform:PREamble?"
if self.resource.interface_type == InterfaceType.usb:
# Setting chunk size to 496 bytes, it seems that SDS sends data
# in 512 bytes chunks via USB.
# Which is 8 packets of 64 bytes, but each packet takes 2 bytes for a header.
# Thus useful payload is 512-8*2 = 496
# see https://patchwork.ozlabs.org/project/qemu-devel/patch/20200317095049.28486-4-kraxel@redhat.com/
# Setting chunk_size for a large number has *catastrophic* results
# on data transfer rate, since we wait for more data
# which is not going to come until timeout expires
resp_bin = self.query_binary_values(
qstr,
datatype="c",
header_fmt="ieee",
container=np.array,
chunk_size=496,
)
else:
resp_bin = self.query_binary_values(
qstr, datatype="c", header_fmt="ieee", container=np.array
)
preamble["Npoints"] = resp_bin[116:120].view(np.int32).item()
preamble["firstPoint"] = resp_bin[132:136].view(np.int32).item()
preamble["sparsing"] = resp_bin[136:140].view(np.int32).item()
preamble["voltsPerDiv"] = resp_bin[156:160].view(np.float32).item()
preamble["verticalOffset"] = resp_bin[160:164].view(np.float32).item()
preamble["codePerDiv"] = resp_bin[164:168].view(np.float32).item()
preamble["adcBit"] = resp_bin[172:174].view(np.int16).item()
preamble["samplingTime"] = resp_bin[176:180].view(np.float32).item()
preamble["trigDelay"] = (
-resp_bin[180:188].view(np.float64).item()
) # manual is wrong, it claims that this int64
return preamble
def getWaveform(
self, chNum, availableNpnts=None, maxRequiredPoints=None, decimate=True
):
"""
For decimate use see ``getRawWaveform``.
In short decimate=True is slower but more precise.
"""
trRaw = self.getRawWaveform(
chNum,
availableNpnts=availableNpnts,
maxRequiredPoints=maxRequiredPoints,
decimate=decimate,
)
preamble = self.getParsedPreamble()
VoltageOffset = preamble["verticalOffset"]
VoltsPerDiv = preamble["voltsPerDiv"]
tr = trRaw
tr.values = trRaw.values * VoltsPerDiv / preamble["codePerDiv"] - VoltageOffset
tr.config["unit"] = "Volt"
tr.config["tags"]["VoltageOffset"] = VoltageOffset
tr.config["tags"]["VoltsPerDiv"] = VoltsPerDiv
tr.config["tags"]["Preamble"] = preamble
return tr
if __name__ == "__main__":
import pyvisa
print("testing")
rm = pyvisa.ResourceManager()
print(rm.list_resources())
# instr = rm.open_resource("TCPIP::192.168.0.62::INSTR")
instr = rm.open_resource("USB0::62700::4119::SDS08A0X806445::0::INSTR")
scope = SDS800XHD(instr)
print(f"ID: {scope.idn}")
# print(f'Ch1 mean: {scope.mean(1)}')
print(f"Ch1 available points: {scope.getAvailableNumberOfPoints(1)}")
print(f"Sample Rate: {scope.getSampleRate()}")
print(f"Time per Div: {scope.getTimePerDiv()}")
print(f"Ch1 Volts per Div: {scope.getChanVoltsPerDiv(1)}")
print(f"Ch1 Voltage Offset: {scope.getChanVoltageOffset(1)}")
print("------ Header start -------------")
print(str.join("\n", scope.getHeader()))
print("------ Header ends -------------")
# ch1 = scope.getTrace(1)
# traces = scope.getAllTraces()
|
