add agilent examples

examples/take_agilent_waveforms.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python
+
+import time
+import pyvxi11
+import datetime
+import csv
+
+def chunks(l, n):
+    """Yield successive n-sized chunks from l."""
+    for i in range(0, len(l), n):
+        yield l[i:i + n]
+
+def take_waveform_word(dev, filename, channel):
+    dev.write(':WAVEFORM:SOURCE ' + channel)
+    dev.write(':WAVEFORM:FORMAT WORD') # ASCII, BYTE, WORD, BINARY
+    dev.write(':WAVEFORM:DATA?')
+    data = dev.read()
+    data = data[int(data[1])+2:-1]
+    if len(data)%2 != 0:
+        raise ValueError('recieved data length not mutiple of 2')
+    dev.write(':WAVEFORM:YINCREMENT?')
+    inc = float(dev.read()[:-1])
+    dev.write(':WAVEFORM:YORIGIN?')
+    offs = float(dev.read()[:-1])
+    values = map(lambda i: ( (ord(i[0])<<8) + ord(i[1]) - ((ord(i[0])&0x80)>>7)*0xffff ) * inc + offs, \
+            chunks(data,2))
+    filename = filename + '.csv'
+    with open(filename, 'wb') as f:
+        wr = csv.writer(f)
+        values = zip(values)
+        for value in values:
+            wr.writerow(value)
+#        wr.writerow(values)
+
+def take_waveform(dev, filename, channel='CHANNEL1', form='ASCII'):
+    dev.write(':WAVEFORM:SOURCE ' + channel)
+    dev.write(':WAVEFORM:FORMAT ' + form) # ASCII, BYTE, WORD, BINARY
+    dev.write(':WAVEFORM:DATA?')
+    data = dev.read()
+    if form == 'WORD':
+        data = data[int(data[1])+2:-1]
+        filename = filename + '.bin'
+    if form == 'ASCII':
+        filename = filename + '.csv'
+    with open(filename, 'w') as f:
+        f.write(data)
+
+
+HOST = 'osc05'
+CHANNEL = 'CHANNEL2'
+CHANNEL = 'WMEMORY1'
+CHANNEL = 'FUNCTION1'
+
+def main():
+    dev = pyvxi11.Vxi11(HOST)
+    dev.open()
+    dev.io_timeout = 300
+    datestring = datetime.datetime.now().strftime('%y-%m-%d_%H-%M-%S')
+
+    filename = 'waveform_' + CHANNEL + '_' + datestring
+#    take_waveform(dev, filename, CHANNEL, 'WORD')
+#    take_waveform(dev, filename, CHANNEL, 'ASCII')
+
+    take_waveform_word(dev, filename, CHANNEL)
+    dev.write(':WAVEFORM:XINCREMENT?')
+    print 'x_increment:' + dev.read()
+    dev.write(':WAVEFORM:XORIGIN?')
+    print 'x_origin:' + dev.read()
+    dev.write(':WAVEFORM:YINCREMENT?')
+    print 'y_increment:' + dev.read()
+    dev.write(':WAVEFORM:YORIGIN?')
+    print 'y_origin:' + dev.read()
+
+    dev.close()
+
+if __name__ == '__main__':
+    main()

examples/take_measurement.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+
+# example to take measurements periodicly after trigger occured
+# calculate simple statistics modes to the measurement values
+# works with tektronix tds series
+
+import sys
+import time
+import pyvxi11
+import datetime
+
+HOST = sys.argv[0]
+
+def main():
+    dev = pyvxi11.Vxi11(HOST)
+    dev.open()
+    dev.io_timeout = 10
+
+    count = 4
+    sum = 0
+    square_sum = 0
+    cube_sum = 0
+    quad_sum = 0
+    min = 0
+    max = 0
+    mean = 0
+    rms = 0
+    skewness = 0
+    ekurtosis = 0
+
+    print datetime.datetime.now().strftime('screen_%y-%m-%d_%Hh%Mm%S.png')
+    start_second = int(datetime.datetime.now().strftime("%s"))
+    dev.write('ACQUIRE:STATE ON')
+
+    while True:
+        state = dev.ask(':ACQ?').split(';')[1]
+        if state == "STATE 0":
+            # capture screenshot
+            value = float(dev.ask('MEASUREMENT:MEAS1:VALUE?').split(' ')[1])
+            count += 1
+            if value > max:
+                max = value
+            if value < min:
+                min = value
+            sum += value
+            square_sum += pow(value, 2)
+            cube_sum += pow(value, 3)
+            quad_sum += pow(value, 4)
+            mean = sum / count
+            rms = pow((square_sum - pow(sum, 2)/count) / (count-1), 0.5)
+            skewness = cube_sum / pow(rms, 3) * count / (count-1) / (count-2)
+            ekurtosis = ( quad_sum / pow(rms, 4) * \
+                (count+1) / (count-1) - 3 * count ) * \
+                count / (count-2) / (count-3)
+            print "%i, %e, %e, %e, %e, %e, %e, %e" % \
+                (count, value, min, max, mean, rms, skewness, ekurtosis)
+
+            # reenable single shot
+            dev.write('ACQUIRE:STATE ON')
+
+    dev.close()
+
+if __name__ == '__main__':
+    main()

examples/tek-screenshot.py

@@ -30,6 +30,7 @@
 f = file(sys.argv[2], 'w')
 v = pyvxi11.Vxi11(sys.argv[1])
 v.open()
+v.io_timeout = 10
 v.write(r'EXPORT:FILENAME "C:\TEMP\SCREEN.PNG"')
 v.write('EXPORT:FORMAT PNG')
 v.write('EXPORT:IMAGE NORMAL')
@@ -38,6 +39,7 @@
 #v.write('EXPORT:VIEW GRATICULE')
 #v.write('EXPORT:VIEW FULLNO')
 v.write('EXPORT START')
+time.sleep(3)
 v.write(r'FILESYSTEM:PRINT "C:\TEMP\SCREEN.PNG", GPIB')
 time.sleep(0.5)
 f.write(v.read())