attribute_id=niscope_types.NiScopeAttributes.
NISCOPE_ATTRIBUTE_FETCH_RELATIVE_TO,
value=niscope_types.NiScopeInt32AttributeValues.
NISCOPE_INT32_FETCH_RELATIVE_TO_VAL_READ_POINTER))).status)
# Fetch continuously until all samples are acquired.
current_pos = 0
samples_per_fetch = 100
while current_pos < total_samples:
# We fetch each channel at a time so we don't have to de-interleave afterwards.
# We do not keep the wfm_info returned from fetch.
for channel_name, waveform in zip(channel_list, waveforms):
fetch_response = client.Fetch(
niscope_types.FetchRequest(vi=vi,
channel_list=channel_name,
timeout=500000,
num_samples=samples_per_fetch))
CheckForError(vi, fetch_response.status)
waveform[current_pos:current_pos +
samples_per_fetch] = fetch_response.waveform
print(
f'Fetching channel {channel_name}\'s waveform for indices {current_pos} to {current_pos + samples_per_fetch - 1}'
)
print()
current_pos += samples_per_fetch
# Close session to NI-SCOPE module.
CheckForError(vi, (client.Close(niscope_types.CloseRequest(vi=vi))).status)
channel.close()
# If NI-SCOPE API throws an exception, print the error message.
niscope_types.ConfigureHorizontalTimingRequest(
vi=vi,
min_sample_rate=50000000,
min_num_pts=samples,
ref_position=50.0,
num_records=1,
enforce_realtime=True))).status)
# Initiate acquisition.
CheckForError(vi, (client.InitiateAcquisition(
niscope_types.InitiateAcquisitionRequest(vi=vi))).status)
# Fetch waveforms.
fetch_response = client.Fetch(
niscope_types.FetchRequest(vi=vi,
channel_list=channels,
timeout=10000,
num_samples=samples))
CheckForError(vi, fetch_response.status)
waveforms = fetch_response.waveform
# Print waveform results.
for i in range(len(waveforms)):
print(f'Waveform {i} information:')
print(f'{waveforms[i]}\n')
# If NI-SCOPE API throws an exception, print the error message.
except grpc.RpcError as rpc_error:
error_message = rpc_error.details()
if rpc_error.code() == grpc.StatusCode.UNAVAILABLE:
error_message = f"Failed to connect to server on {server_address}:{server_port}"
elif rpc_error.code() == grpc.StatusCode.UNIMPLEMENTED:
def on_close(event):
global closed
closed = True
fig.canvas.mpl_connect('close_event', on_close)
print("\nReading values in loop. CTRL+C to stop.\n")
try:
while not closed:
# Clear the plot and setup the axis
fig.clf()
plt.axis([0, 500, -6, 6])
# Fetch a waveform from the scope
for i in range(len(sessions)):
fetch_result = scope_service.Fetch(
niscope_types.FetchRequest(vi=sessions[i],
channel_list=channels,
timeout=1,
num_samples=500))
CheckForError(scope_service, session, fetch_result.status)
plt.subplot(1, len(sessions), i + 1, label=str(i))
# Round the array to 2 decimal places and Update the plot with the new waveform
data = np.array(fetch_result.waveform[0:500])
# Add labels for axes and legends
plt.ylabel('Amplitude')
plt.xlabel('Samples')
plt.plot(np.round(data, 2))
plt.title(label='$Scope{i}$'.format(i=i))
plt.subplots_adjust(wspace=0.5)
plt.pause(0.001)
time.sleep(0.1)
except KeyboardInterrupt:
pass