def saveTrace(filename=''):
''' Very basic, give it a file name and it will save a trace from SpecAn'''
date_string = datetime.datetime.today().strftime('%y-%m-%d')
filepath = "C:\Users\Milos\Desktop\James\\" + date_string + ' ' + filename + '.txt'
try:
os.remove(filename)
except OSError:
pass
file = open(filepath, 'w')
#Write header
SpecAn.write('CF?')
center = float(SpecAn.read())
SpecAn.write('SP?')
span = float(SpecAn.read())
file.write('Center freq: ' + str(center) + ' Span: ' + str(span) + '\n')
SpecAn.write('RL?')
ref_level = SpecAn.read()
file.write('Reference Level: ' + ref_level + '\n')
spec_data_temp = getTrace()
data_db = SIH.convert2db(SpecAn, spec_data_temp)
x = np.linspace(center - span / 2, center + span / 2, 601)
data = np.vstack([x, data_db]).T
np.savetxt(file, data, fmt='%.10e')
file.close()
def quick_rec(SpecAn, filename):
filepath = "C:\Users\Milos\Desktop\James\\" + filename + '.txt'
try:
os.remove(filename)
except OSError:
pass
file = open(filepath, 'w')
span = float(SpecAn.query('SP?'))
center = float(SpecAn.query('CF?'))
x = np.linspace(center - span / 2, center + span / 2, 601)
spec_data_temp = np.zeros(601)
#Gets the trace from the SpecAn
SpecAn.write('TRA?')
binary = SpecAn.read_raw()
spec_data_temp = np.frombuffer(
binary, '>u2') # Data format is big-endian unsigned integers
spec_data_db = SIH.convert2db(SpecAn, spec_data_temp)
#Conjoins both x and spec_data_temp vectors and saves them to file
data = np.vstack([x, spec_data_db]).T
np.savetxt(file, data, fmt='%.10e')
def multi_record(SpecAn, d_time, n, filepath):
'''Takes 'n' scans on the HP Spectrum Analyzer at ~d_time intervals.
This is an augmented version of record_trace from holeburn_james.
Also records the times for each data recording event.'''
#Run the following first to set up the text file.
#hb.create_file(SpecAn, filename = '', compensated = 'N', sweep_again = 'Y', n=1, burn_time = '')
SpecAn.write('SP?')
span = float(SpecAn.read())
SpecAn.write('CF?')
center = float(SpecAn.read())
file = open(filepath, 'a')
x = np.linspace(center - span / 2, center + span / 2, 601)
spec_data_db = np.zeros((601, n))
record_time = []
for i in range(n):
SpecAn.write('TS')
#Waits for Spectrum Analyser to finish Data sweep
SpecAn.wait_for_srq(timeout=30000)
#Gets the trace from the SpecAn
SpecAn.write('TRA?')
binary = SpecAn.read_raw()
spec_data_temp = np.frombuffer(
binary, '>u2') # Data format is big-endian unsigned integers
record_time.append(datetime.now().strftime("%H:%M:%S.%f"))
spec_data_db[:, i] = SIH.convert2db(SpecAn, spec_data_temp)
if compensated == 'Y':
spec_data_db[:, i] = compensate(spec_data_temp, span)
SpecAn.write("CLEAR; RQS 4")
pb.Sequence([(['ch2', 'ch5'], d_time)],
[(['ch2', 'ch5', 'ch4'], 1 * ms)],
loop=False)
#Conjoins both x and spec_data_temp vectors and saves them to file
data = np.vstack([x, spec_data_db]).T
np.savetxt(file, data, fmt='%.10e')
file.close()
pylab.ion()
if sweep_again == 'Y':
HP8560E_SpecAn_Trigger("FREE", 'CONTS', SpecAn)
return x, spec_data_db, filepath
def record_trace(SpecAn,
filepath,
filename='',
compensated='Y',
sweep_again='Y',
n=1,
burn_time='',
opt_bac=''):
''' Records a single trace from SpecAn '''
SpecAn.write('SP?')
span = float(SpecAn.read())
SpecAn.write('CF?')
center = float(SpecAn.read())
SpecAn.write('TS')
#Waits for Spectrum Analyser to finish Data sweep
SpecAn.wait_for_srq(timeout=30000)
## import time
## #time.sleep(10)
file = open(filepath, 'a')
x = np.linspace(center - span / 2, center + span / 2, 601)
spec_data_temp = np.zeros(601)
#Gets the trace from the SpecAn
SpecAn.write('TRA?')
binary = SpecAn.read_raw()
spec_data_temp = np.frombuffer(
binary, '>u2') # Data format is big-endian unsigned integers
spec_data_db = SIH.convert2db(SpecAn, spec_data_temp)
if compensated == 'Y':
spec_data_db = compensate(spec_data_db, span, opt_back=opt_bac)
#Conjoins both x and spec_data_temp vectors and saves them to file
data = np.vstack([x, spec_data_db]).T
np.savetxt(file, data, fmt='%.10e')
file.close()
pylab.ion()
if sweep_again == 'Y':
HP8560E_SpecAn_Trigger("FREE", 'CONTS', SpecAn)
return filepath
def laser_stability_measure(freq,
t_space=100 * ms,
t=4 * s,
f_name='',
show='Y'):
[SpecAn, SpecAn_Bool] = Initialise_HP8560E_SpecAn()
SpecAn.write('ST 0.05') #Sweep Time 50ms
n = int(t / t_space) #Amount of times scans needed
## mc.setup(centerFreqL = freq, widthL = 10e4, sweepTimeL = 1e-4)
if t_space < 50 * ms:
raise RuntimeError, "SpecAn's fastest sweep time & reset is 100ms, t_space cannot be faster."
file = make_file(f_name)
span = 5 * MHz
freq_sit = freq
SpecAn.write('CF ' + str(freq_sit))
SpecAn.write('SP ' + str(span))
time.sleep(0.5)
#Take Background measurement
SIH.save_offset(10, 'n')
#Burn a hole
pb.Sequence([(['ch1'], 50 * ms), (['ch2', 'ch4', 'ch5'], 1 * ms)],
loop=False)
HP8560E_SpecAn_Trigger('EXT', 'CONTS', SpecAn)
print "Recording for {}s at {} Hz".format(t, 1 / t_space)
#Get raw data
l = []
for k in range(n):
l.append([time.time(), getTrace(SpecAn, t_space)])
HP8560E_SpecAn_Trigger('FREE', 'CONTS', SpecAn)
t_init = l[0][0]
t_arr = []
center = []
freq_arr = np.linspace(freq_sit - span / 2, freq_sit + span / 2, 601)
for i in range(n):
#Convert to dB and background subtract post data collection
dat = SIH.convert2db(SpecAn, l[i][1])
dat = hb.compensate(dat, span)
#Make time and freq peak array
t_arr.append(l[i][0] - t_init)
index = np.argmax(
dat[50:]) #The carrier also makes a hole, this should ignore it
center.append(freq_arr[index])
data = np.vstack([t_arr, center]).T
np.savetxt(file, data, fmt='%.10e')
##
pb.Sequence([(['ch2', 'ch5', 'ch4'], 1 * ms)], loop=False)
#Plot
if show == 'Y':
plt.plot(t_arr, center)
plt.show()
return l, t_arr, center, data