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"""
Provide basic class to build an operational scope
Created by Eugeniy E. Mikhailov 2021/11/29
"""
import numpy as np
from qolab.hardware.scpi import SCPIinstr
from qolab.hardware.basic import BasicInstrument
from qolab.data.trace import TraceSetSameX
import time
import logging
logging.basicConfig(
format="%(asctime)s %(levelname)8s %(name)s: %(message)s",
datefmt="%m/%d/%Y %H:%M:%S",
)
logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)
def calcSparsingAndNumPoints(availableNpnts=None, maxRequiredPoints=None):
"""Calculate sparcing and number of sparced points.
Parameters
----------
availableNpnts: int or None (throws error)
Number of available points. If set to None exit with error
maxRequiredPoints: int or None (throws error)
number of requested points after decimation.
If availableNpnts< maxRequiredPoints*2,
decimation is impossible and we will get up to factor of 2 more
than requested.
Return
------
(sparsing, Npnts, availableNpnts, maxRequiredPoints)
"""
if availableNpnts is None:
raise ValueError("Invalid availableNpnts value, must be int.")
if maxRequiredPoints is None:
raise ValueError("Invalid maxRequiredPoints value, must be int.")
if availableNpnts <= maxRequiredPoints * 2:
Npnts = availableNpnts
sparsing = 1
else:
sparsing = int(np.floor(availableNpnts / maxRequiredPoints))
Npnts = int(np.floor(availableNpnts / sparsing))
return (sparsing, Npnts, availableNpnts, maxRequiredPoints)
class Scope(BasicInstrument):
"""Minimal class to implement a scope.
Intended to be used as a parent for hardware aware scopes.
Provide a minimal set of methods to be implemented by a scope.
"""
def __init__(self, *args, **kwds):
BasicInstrument.__init__(self, *args, **kwds)
self.config["Device type"] = "Scope"
self.config["Device model"] = "Generic Scope Without Hardware interface"
self.config["FnamePrefix"] = "scope"
self.numberOfChannels = 0
# deviceProperties must have 'get' and preferably 'set' methods available,
# i.e. 'SampleRate' needs getSampleRate() and love to have setSampleRate(value)
# they will be used to obtain config and set device according to it
self.deviceProperties.update(
{"SampleRate", "TimePerDiv", "TrigDelay", "TriggerMode", "Roll", "Run"}
)
# same is applied to channelProperties
# but we need setter/getter with channel number
# i.e. VoltsPerDiv must provide
# getChanVoltsPerDiv(chNum) and setSampleRate(chNum, value)
self.channelProperties = {
"VoltsPerDiv",
"VoltageOffset",
}
def getTrace(
self, chNum, availableNpnts=None, maxRequiredPoints=None, decimate=True
):
# Should work with minimal arguments list
# but might be faster if parameters provided: less IO requests
# old_trg_mode = self.getTriggerMode()
# self.setTriggerMode('STOP'); # to get synchronous channels
raise NotImplementedError("getTrace function is not implemented")
# if old_trg_mode != "STOP":
# short speed up here with this check
# self.setTriggerMode(old_trg_mode)
def getTriggerMode(self):
# we expect NORM, AUTO, SINGLE
raise NotImplementedError("getTriggerMode function is not implemented")
def setTriggerMode(self, mode):
# we expect NORM, AUTO, SINGLE
raise NotImplementedError("setTriggerMode function is not implemented")
def getRun(self):
"""Is acquisition running or stopped."""
raise NotImplementedError("getRun function is not implemented")
def setRun(self, val):
"""Either enable run or stop the acquisition."""
raise NotImplementedError("setRun function is not implemented")
def _waitUntillStop(self, timeout=1):
"""Wait until scope in the stop state.
Just because we ask for a scope to stop, does not mean
that it is stopped. It can still wait for a trigger or untill
the time span is filled.
Parameter
---------
timeout : float
timeout in seconds, default is 1 second
"""
starttime = time.time()
deadline = starttime + timeout
while time.time() < deadline:
if self.getRun():
time.sleep(0.010)
else:
logger.debug(f"Scope stopped within {time.time()-starttime} seconds.")
return
logger.warning(
f"Scope did not reach STOP state within {timeout=} sec, try to increase it."
)
def getAllTraces(self, availableNpnts=None, maxRequiredPoints=None, decimate=True):
allTraces = TraceSetSameX("scope traces")
allTraces.config["tags"]["DAQ"] = self.getConfig()
old_run_status = self.getRun()
if old_run_status: # avoid unnecessary status change
self.setRun(False) # stop if currently running
self._waitUntillStop()
# to get synchronous channels
for chNum in range(1, self.numberOfChannels + 1):
allTraces.addTrace(
self.getTrace(
chNum,
availableNpnts=availableNpnts,
maxRequiredPoints=maxRequiredPoints,
decimate=decimate,
)
)
# restore scope to the before acquisition mode
if old_run_status: # avoid unnecessary status change
self.setRun(old_run_status) # start running if it was old run state
return allTraces
def chanAutoScale(self, chNum, margin=0.125, timeout=5):
"""Auto scale channel to fit signal on screen.
Tunes Volts per division and Channel offset to fit signal
on screen (vertically).
Parameters
----------
chNum : int
Channel to auto scale
margin: float
How much extra space (margin) to have with respect to full screen.
Default is 0.125 (i.e. 12.5%).
Note that margin = 0.25 corresponds to 1 vertical division
at top and bottom for 8 division scope.
"""
starttime = time.time()
deadline = starttime + timeout
scaled_corectly = False
# maximally zoom out to get full signal
self.setChanVoltageOffset(chNum, 0)
self.setChanVoltsPerDiv(chNum, 10)
self.setRun(True)
while (not scaled_corectly) and (time.time() < deadline):
tr = self.getTrace(chNum)
vPerDiv = self.getChanVoltsPerDiv(chNum)
offset = self.getChanVoltageOffset(chNum)
v_range = vPerDiv * self.vertDivOnScreen
v_max = v_range / 2 - offset
v_min = -v_range / 2 - offset
y = tr.y.values
tr_max = y.max()
tr_min = y.min()
margin_t = (v_max - tr_max) / v_range
margin_b = (tr_min - v_min) / v_range
is_margin_t_good = (margin_t > margin * 0.5) and (margin_t < margin*0.6)
is_margin_b_good = (margin_b > margin * 0.5) and (margin_b < margin*0.6)
if (is_margin_b_good) and (is_margin_t_good):
scaled_corectly = True
break
offset = -(tr_max + tr_min) / 2
vPerDiv = (tr_max - tr_min) / (self.vertDivOnScreen * (1 - margin * 1.2))
logger.info(f"Requesting {offset=} for {chNum=}.")
self.setChanVoltageOffset(chNum, offset)
logger.info(f"Requesting {vPerDiv=} for {chNum=}.")
self.setChanVoltsPerDiv(chNum, vPerDiv)
scaled_corectly = False
if time.time() > deadline:
logger.warning(
f"Scope did not make proper channel {chNum} scaling within {timeout=} sec."
)
def plot(self, **kwargs):
allTraces = self.getAllTraces(**kwargs)
allTraces.plot()
def save(
self,
fname=None,
item_format="e",
availableNpnts=None,
maxRequiredPoints=None,
decimate=True,
extension="dat",
):
allTraces = self.getAllTraces(
availableNpnts=availableNpnts,
maxRequiredPoints=maxRequiredPoints,
decimate=decimate,
)
allTraces.config["item_format"] = item_format
if fname is None:
fname = self.getNextDataFile(extension=extension)
allTraces.save(fname)
print(f"Data saved to: {fname}")
return fname
class ScopeSCPI(SCPIinstr, Scope):
"""SCPI aware scope.
Use as a parent for a hardware aware scope classes.
Example
-------
>>> rm = pyvisa.ResourceManager()
>>> ScopeSCPI(rm.open_resource('TCPIP::192.168.0.2::INSTR'))
"""
def __init__(self, resource, *args, **kwds):
SCPIinstr.__init__(self, resource)
Scope.__init__(self, *args, **kwds)
self.config["DeviceId"] = str.strip(self.idn)
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