New ps6000a External Clock example

Author: AndrewAPico

ps6000aExamples/ps6000aBlockExampleExtClk.py

@@ -0,0 +1,168 @@
+#
+# Copyright (C) 2020 Pico Technology Ltd. See LICENSE file for terms.
+#
+# PS6000A Demonstrates external clock callback using block mode.
+# This example opens a 6000a driver device, sets up the External clock callback, and reports its status during a block capture.
+# Data is then plotted as mV against time in ns.
+
+import ctypes
+import numpy as np
+from picosdk.ps6000a import ps6000a as ps
+from picosdk.PicoDeviceEnums import picoEnum as enums
+import matplotlib.pyplot as plt
+from picosdk.functions import adc2mV, assert_pico_ok
+from picosdk.constants import PICO_STATUS
+import time
+
+# Create chandle and status ready for use
+chandle = ctypes.c_int16()
+status = {}
+
+# Open 6000 A series PicoScope
+# returns handle to chandle for use in future API functions
+resolution = enums.PICO_DEVICE_RESOLUTION["PICO_DR_8BIT"]
+status["openunit"] = ps.ps6000aOpenUnit(ctypes.byref(chandle), None, resolution)
+assert_pico_ok(status["openunit"])
+
+# setup External clock callback function
+wasCalledBack = False
+ExtRefClk_PicoStatus = enums.PICO_STATUS["PICO_OK"]
+ExtRefClkReference = enums.PICO_CLOCK_REFERENCE["PICO_INTERNAL_REF"]
+
+def ExternalReferenceInteractions_callback(handle, statusCallback, reference):
+    global wasCalledBack, ExtRefClk_PicoStatus, ExtRefClkReference
+    wasCalledBack = True
+    ExtRefClkReference = reference
+    ExtRefClk_PicoStatus = statusCallback
+    
+# Convert the python function into a C function pointer.
+cFuncPtrExtClkCB = ps.ExternalReferenceInteractionsReadyType(ExternalReferenceInteractions_callback) 
+# Register the External clock callback
+status["SetExternalReferenceInteractionCallback"] = ps.ps6000aSetExternalReferenceInteractionCallback(chandle, cFuncPtrExtClkCB)
+assert_pico_ok(status["SetExternalReferenceInteractionCallback"])
+
+time.sleep(1)
+
+if wasCalledBack == True:
+    print("ExtRefClk_PicoStatus = ", ExtRefClk_PicoStatus)
+    print("ExtRefClk_Reference = ", ExtRefClkReference)
+    wasCalledBack = False
+
+# Set channel A on
+# handle = chandle
+channelA = enums.PICO_CHANNEL["PICO_CHANNEL_A"]
+coupling = enums.PICO_COUPLING["PICO_DC"]
+channelRange = 7
+
+# analogueOffset = 0 V
+bandwidth = enums.PICO_BANDWIDTH_LIMITER["PICO_BW_FULL"]
+status["setChannelA"] = ps.ps6000aSetChannelOn(chandle, channelA, coupling, channelRange, 0, bandwidth)
+assert_pico_ok(status["setChannelA"])
+
+# set channel B-H off
+for x in range (1, 7, 1):
+    channel = x
+    status["setChannel",x] = ps.ps6000aSetChannelOff(chandle,channel)
+    assert_pico_ok(status["setChannel",x])
+
+# Set simple trigger on channel A, 1 V rising with 1 s autotrigger
+# handle = chandle
+# enable = 1
+source = channelA
+# threshold = 1000 mV
+direction = enums.PICO_THRESHOLD_DIRECTION["PICO_RISING"]
+# delay = 0 s
+# autoTriggerMicroSeconds = 1000000 us
+status["setSimpleTrigger"] = ps.ps6000aSetSimpleTrigger(chandle, 1, source, 1000, direction, 0, 1000000)
+assert_pico_ok(status["setSimpleTrigger"])
+
+# Get fastest available timebase
+# handle = chandle
+enabledChannelFlags = enums.PICO_CHANNEL_FLAGS["PICO_CHANNEL_A_FLAGS"]
+timebase = ctypes.c_uint32(0)
+timeInterval = ctypes.c_double(0)
+
+# resolution = resolution
+status["getMinimumTimebaseStateless"] = ps.ps6000aGetMinimumTimebaseStateless(chandle, enabledChannelFlags, ctypes.byref(timebase), ctypes.byref(timeInterval), resolution)
+timebase = ctypes.c_uint32(1000)
+print("timebase = ", timebase.value)
+print("sample interval =", timeInterval.value, "s")
+
+# Set number of samples to be collected
+noOfPreTriggerSamples = 500000
+noOfPostTriggerSamples = 1000000
+nSamples = noOfPostTriggerSamples + noOfPreTriggerSamples
+
+# Create buffers
+bufferAMax = (ctypes.c_int16 * nSamples)()
+bufferAMin = (ctypes.c_int16 * nSamples)() # used for downsampling which isn't in the scope of this example
+
+# Set data buffers
+# handle = chandle
+# channel = channelA
+# bufferMax = bufferAMax
+# bufferMin = bufferAMin
+# nSamples = nSamples
+dataType = enums.PICO_DATA_TYPE["PICO_INT16_T"]
+waveform = 0
+downSampleMode = enums.PICO_RATIO_MODE["PICO_RATIO_MODE_RAW"]
+clear = enums.PICO_ACTION["PICO_CLEAR_ALL"]
+add = enums.PICO_ACTION["PICO_ADD"]
+action = clear|add # PICO_ACTION["PICO_CLEAR_WAVEFORM_CLEAR_ALL"] | PICO_ACTION["PICO_ADD"]  
+status["setDataBuffers"] = ps.ps6000aSetDataBuffers(chandle, channelA, ctypes.byref(bufferAMax), ctypes.byref(bufferAMin), nSamples, dataType, waveform, downSampleMode, action)
+assert_pico_ok(status["setDataBuffers"])
+
+# Run block capture
+# handle = chandle
+# timebase = timebase
+timeIndisposedMs = ctypes.c_double(0)
+# segmentIndex = 0
+# lpReady = None   Using IsReady rather than a callback
+# pParameter = None
+status["runBlock"] = ps.ps6000aRunBlock(chandle, noOfPreTriggerSamples, noOfPostTriggerSamples, timebase, ctypes.byref(timeIndisposedMs), 0, None, None)
+assert_pico_ok(status["runBlock"])
+
+# Check for data collection to finish using ps6000aIsReady
+# Also print any change to the samaple clock source
+ready = ctypes.c_int16(0)
+check = ctypes.c_int16(0)
+while ready.value == check.value:
+    status["isReady"] = ps.ps6000aIsReady(chandle, ctypes.byref(ready))
+    if wasCalledBack == True:
+        print("ExtRefClk_Reference = ", ExtRefClkReference)
+        wasCalledBack = False
+
+# Get data from scope
+# handle = chandle
+# startIndex = 0
+noOfSamples = ctypes.c_uint64(nSamples)
+# downSampleRatio = 1
+# segmentIndex = 0
+overflow = ctypes.c_int16(0)
+status["getValues"] = ps.ps6000aGetValues(chandle, 0, ctypes.byref(noOfSamples), 1, downSampleMode, 0, ctypes.byref(overflow))
+assert_pico_ok(status["getValues"])
+
+# get max ADC value
+# handle = chandle
+minADC = ctypes.c_int16()
+maxADC = ctypes.c_int16()
+status["getAdcLimits"] = ps.ps6000aGetAdcLimits(chandle, resolution, ctypes.byref(minADC), ctypes.byref(maxADC))
+assert_pico_ok(status["getAdcLimits"])
+
+# convert ADC counts data to mV
+adc2mVChAMax =  adc2mV(bufferAMax, channelRange, maxADC)
+
+# Create time data
+time = np.linspace(0, (nSamples -1) * timeInterval.value * 1000000000, nSamples)
+
+# plot data from channel A and B
+plt.plot(time, adc2mVChAMax[:])
+plt.xlabel('Time (ns)')
+plt.ylabel('Voltage (mV)')
+plt.show()
+
+# Close the scope
+status["closeunit"] = ps.ps6000aCloseUnit(chandle)
+assert_pico_ok(status["closeunit"])
+
+print(status)