""" 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. """ vertDivOnScreen = 8 # should be adjusted in hardware aware class horizDivOnScreen = 8 # should be adjusted in hardware aware class minVoltsPerDiv = 0.001 # should be adjusted in hardware aware class 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 restorePriorToFastGrab(self, chNum, old_config): """Restore relevant channel/scope settings prior to fast grab tune up.""" logger.info("method restorePriorToFastGrab is not implemented") def switchToFastGrab(self, chNum): """Switch scope to the fastest mode for trace delivery. Intended to be used in chanAutoScale methods where speed transfer is more important than fidelity. It is good idea to implement function ``restorePriorToFastGrab(chan, old_config)`` to be used in conjunction with ``switchToFastGrab``. To be fast, it should aim to decrease data transfer time, i.e. reduce number of transferred point. It also need to be interface dependent. GPIB and USB are known to be quite slow when compared to network connection. So try to be smart in hardware dependent classes. Return ------ old_config : dictionary old config with settings necessary to restore initial state """ logger.info("machinery for switchToFastGrab is not implemented") return self.getConfig() 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. """ old_config = self.switchToFastGrab(chNum) starttime = time.time() deadline = starttime + timeout timespan = self.getTimePerDiv() * self.horizDivOnScreen scaled_corectly = False self.setRun(True) while (not scaled_corectly) and (time.time() < deadline): time.sleep( timespan + 0.5 ) # give enough time to acquire a trace and switch to Run 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() signal_range = tr_max - tr_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 * 1.0) is_margin_b_good = (margin_b > margin * 0.5) and (margin_b < margin * 1.0) if (is_margin_b_good) and (is_margin_t_good): scaled_corectly = True break old_offset = offset old_vPerDiv = vPerDiv offset = -(tr_max + tr_min) / 2 if min(margin_t, margin_b) < 0.01: # too close to edge, zoom out vPerDiv *= 2 elif (signal_range / v_range) < 0.2: # signal is too small, zoom in vPerDiv /= 2 else: vPerDiv = signal_range / (self.vertDivOnScreen * (1 - margin * 1.2)) if vPerDiv < self.minVoltsPerDiv: vPerDiv = self.minVoltsPerDiv logger.debug(f"Auto Scaler Requesting {vPerDiv=} for {chNum=}.") self.setChanVoltsPerDiv(chNum, vPerDiv) logger.debug(f"Auto Scaler Requesting {offset=} for {chNum=}.") self.setChanVoltageOffset(chNum, offset) relOffsetChange = abs(old_offset - offset) / old_vPerDiv relVperDivChange = abs(old_vPerDiv - vPerDiv) / old_vPerDiv if (relOffsetChange < 0.5) and (relVperDivChange < 0.05): # we converge, there is no point to improve break scaled_corectly = False self.restorePriorToFastGrab(chNum, old_config) 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)