def open_connection():
gpib.open_connection()
gpib.set_address(24)
gpib.clear_selected_device() # clear keithley
gpib.write("*IDN?") # ask instrument to identify itself
reading = gpib.readline()
if "KEITHLEY INSTRUMENTS INC.,MODEL 2400" in reading:
gpib.write("OUTP ON") # Enable the Keithley's output
else:
raise Error("ERROR: The Keithley 2400 is not responding.")
def open_connection():
gpib.open_connection()
gpib.set_address(24)
gpib.clear_selected_device() # clear keithley
gpib.write("*IDN?") # ask instrument to identify itself
reading = gpib.readline()
if "KEITHLEY INSTRUMENTS INC.,MODEL 2400" in reading:
gpib.write("OUTP ON") # Enable the Keithley's output
else:
raise Error("ERROR: The Keithley 2400 is not responding.")
def read(interval = 0, samples = 1, update_graph = do_nothing, *args):
gpib.write("ARM:COUN 1") # arm instrument
gpib.write("TRIG:COUN %d" % samples) # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
Time = []
Data = []
CurrentSample = 0
gpib.write("READ?") # start measurement
while len(Data) < samples:
while CurrentSample < len(Data):
update_graph(Time[CurrentSample], Data[CurrentSample], figure)
CurrentSample = CurrentSample + 1
time.sleep(interval)
DataString = gpib.readline()
DataString = DataString.split(',')
for i in range(len(DataString)):
if len(DataString[i]) > 0:
#print DataString[i]
if DataString[i] != '\x00\x00\x00': # some 2400s return this if no data
Time.append(float(len(Data) * interval))
Data.append(float(DataString[i]))
while CurrentSample < len(Data):
update_graph(Time[CurrentSample], Data[CurrentSample], *args)
CurrentSample = CurrentSample + 1
if samples > 1:
return Time, Data
else:
return Data[0]
def read(interval=0, samples=1, update_graph=do_nothing, *args):
gpib.write("ARM:COUN 1") # arm instrument
gpib.write("TRIG:COUN %d" % samples) # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
Time = []
Data = []
CurrentSample = 0
gpib.write("READ?") # start measurement
while len(Data) < samples:
while CurrentSample < len(Data):
update_graph(Time[CurrentSample], Data[CurrentSample], figure)
CurrentSample = CurrentSample + 1
time.sleep(interval)
DataString = gpib.readline()
DataString = DataString.split(',')
for i in range(len(DataString)):
if len(DataString[i]) > 0:
#print DataString[i]
if DataString[
i] != '\x00\x00\x00': # some 2400s return this if no data
Time.append(float(len(Data) * interval))
Data.append(float(DataString[i]))
while CurrentSample < len(Data):
update_graph(Time[CurrentSample], Data[CurrentSample], *args)
CurrentSample = CurrentSample + 1
if samples > 1:
return Time, Data
else:
return Data[0]
def open_connection():
gpib.open_connection()
gpib.write("++addr 27") # set GPIB address to the Keithley 617
gpib.clear_selected_device() # Reset Keithley
gpib.write("C0X") # turn off zero check
gpib.write("C0X") # again, just to make sure :)
reading = gpib.readline() # make sure Keithley's turned on
if not "DC" in reading:
raise Error("ERROR: The Keithley 617 is not responding, make "\
"sure it is turned on.")
def enable_live_readings():
gpib.write("ARM:COUN INF") # infinite arm count
gpib.write("TRIG:DEL 0") # zero trigger delay
gpib.write("INIT") # start measurements
def enable_voltage_source():
gpib.write("O1X")
def current_mode():
gpib.write("SOUR:FUNC VOLT")
gpib.write("SOUR:VOLT 0")
gpib.write("CONF:CURR")
gpib.write("FORM:ELEM CURR")
time.sleep(1)
def read_one(interval = 0):
#gpib.write("ARM:COUN 1")
#gpib.write("ARM:SOUR BUS")
gpib.write("TRIG:COUN 1") # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
gpib.write("INIT") # start measurement
#gpib.write("*TRG")
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
RAV = 1 << 6
reading_available = measurement_event & RAV
while not reading_available:
#print str(measurement_event) + ", " + str(reading_available)
time.sleep(interval)
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
reading_available = measurement_event & RAV
#gpib.write("*CLS") # clear event registers
#time.sleep(interval)
gpib.write("FETC?")
gpib.write("++read 10")
Datum = gpib.readline()
print "reading: " + Datum
return Datum
def display_voltage_source():
gpib.write("D1X")
def read_one(interval = 0):
if interval == 0:
gpib.write("B1Q0G2X") # store data as fast as possible
elif interval == 1:
gpib.write("B1Q1G2X") # store data every 1 s
elif interval == 10:
gpib.write("B1Q2G2X") # store data every 10 s
elif interval == 60:
gpib.write("B1Q3G2X") # store data every 60 s
elif interval == 600:
gpib.write("B1Q4G2X") # store data every 600 s
elif interval == 3600:
gpib.write("B1Q5G2X") # store data every 3600 s
else:
raise Error("ERROR: The Keithley 617 allows sample intervals of " + \
"0, 1, 10, 60, 600, or 3600 seconds.")
#gpib.flushInput() # discard any previous readings
samples = 2
Data = []
CurrentSample = 1
Datum = gpib.readline()
while CurrentSample <= samples:
if ",%03d" % CurrentSample in Datum:
Data = Data + [float(Datum[4:Datum.find(',')])]
CurrentSample = CurrentSample + 1
time.sleep(interval)
elif ",%03d" % (CurrentSample -1) in Datum:
time.sleep(interval)
gpib.write("B1X") # get a reading
Datum = gpib.readline()
gpib.write("Q7X") # turn off data storage
return Data[-1]
def resistance_mode():
gpib.write("CONF:RES")
gpib.write("FORM:ELEM RES")
def voltage_mode():
gpib.write("SOUR:FUNC CURR")
gpib.write("SOUR:CURR 0")
gpib.write("CONF:VOLT")
gpib.write("FORM:ELEM VOLT")
time.sleep(1)
def current_mode():
gpib.write("F1X")
time.sleep(1)
def disable_voltage_source():
gpib.write("SOUR:VOLT 0")
def voltage_mode():
gpib.write("F0X")
time.sleep(1)
def set_voltage_source(voltage):
if abs((voltage / 0.05) - round(voltage / 0.05)) > 1e-10:
print 'Warning: The voltage source in the Keithley 617 has a ' \
'maximum resolution of 50 mV.'
gpib.write("V" + "%.2f" % voltage + "X")
def resistance_mode():
gpib.write("F2X")
time.sleep(1)
def disable_voltage_source():
gpib.write("SOUR:VOLT 0")
def read_one(interval=0):
#gpib.write("ARM:COUN 1")
#gpib.write("ARM:SOUR BUS")
gpib.write("TRIG:COUN 1") # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
gpib.write("INIT") # start measurement
#gpib.write("*TRG")
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
RAV = 1 << 6
reading_available = measurement_event & RAV
while not reading_available:
#print str(measurement_event) + ", " + str(reading_available)
time.sleep(interval)
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
reading_available = measurement_event & RAV
#gpib.write("*CLS") # clear event registers
#time.sleep(interval)
gpib.write("FETC?")
gpib.write("++read 10")
Datum = gpib.readline()
print "reading: " + Datum
return Datum
def resistance_mode():
gpib.write("CONF:RES")
gpib.write("FORM:ELEM RES")
def read_multiple(interval = 0, samples = 1, update_graph = do_nothing, *args):
if interval not in [0, 1, 10, 60, 600, 3600]:
raise Error("ERROR: The Keithley 617 allows interval values of " + \
"0, 1, 10, 60, 600, and 3600")
if samples > 100:
raise Error("ERROR: The Keithley 617 allows a maximum of 100 samples.")
#gpib.flushInput() # discard any previous readings
if interval == 0:
gpib.write("B1Q0G2X") # store data as fast as possible
elif interval == 1:
gpib.write("B1Q1G2X") # store data every 1 s
elif interval == 10:
gpib.write("B1Q2G2X") # store data every 10 s
elif interval == 60:
gpib.write("B1Q3G2X") # store data every 60 s
elif interval == 600:
gpib.write("B1Q4G2X") # store data every 600 s
elif interval == 3600:
gpib.write("B1Q5G2X") # store data every 3600 s
else:
raise Error("ERROR: The Keithley 617 allows sample intervals of " + \
"0, 1, 10, 60, 600, or 3600 seconds.")
Time = []
Data = []
CurrentSample = 1
time.sleep(interval)
Datum = gpib.readline()
while CurrentSample <= samples:
if ",%03d" % CurrentSample in Datum:
Data = Data + [float(Datum[4:Datum.find(',')])]
if interval == 0:
# Keithley617 manual page 3-24
Time = Time + [(CurrentSample - 1) * 0.360]
else:
Time = Time + [(CurrentSample - 1) * interval]
CurrentSample = CurrentSample + 1
# call graph update function
update_graph(Time[-1], Data[-1], *args)
time.sleep(interval)
elif ",%03d" % (CurrentSample -1) in Datum:
time.sleep(interval)
gpib.write("B1X") # get a reading
Datum = gpib.readline()
gpib.write("Q7X") # turn off data storage
return Time, Data
def set_voltage_source(voltage):
if abs((voltage / 5e-6) - round(voltage / 5e-6)) > 1e-10:
print 'Warning: The voltage source in the Keithley 2400 has a ' \
'maximum resolution of 5 uV.'
gpib.write("SOUR:VOLT " + str(voltage))
def set_voltage_source(voltage):
if abs((voltage / 5e-6) - round(voltage / 5e-6)) > 1e-10:
print 'Warning: The voltage source in the Keithley 2400 has a ' \
'maximum resolution of 5 uV.'
gpib.write("SOUR:VOLT " + str(voltage))
def read_old(interval=0, samples=1, update_graph=do_nothing):
RAV = 1 << 6
gpib.write("TRIG:COUN 1") # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
Time = []
Data = []
CurrentSample = 1
Datum = gpib.readline()
gpib.write("INIT") # start measurement
while CurrentSample <= samples:
reading_available = 0
while not reading_available:
#print str(measurement_event) + ", " + str(reading_available)
time.sleep(interval)
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
reading_available = measurement_event & RAV
gpib.write("FETC?")
gpib.write("++read 10")
gpib.write("INIT") # start measurement
Datum = gpib.readline()
#print Datum
#Data = Data + [float(Datum[4:Datum.find(',')])]
Data = Data + [float(Datum)]
Time = Time + [(CurrentSample - 1) * interval]
CurrentSample = CurrentSample + 1
update_graph(Time[-1], Data[-1]) # call graph update function
gpib.write("ARM:COUN INF") # return instrument to live mode
gpib.write("TRIG:DEL 0")
gpib.write("INIT") # start measurements
if samples > 1:
return Time, Data
else:
return float(Datum)
def voltage_mode():
gpib.write("SOUR:FUNC CURR")
gpib.write("SOUR:CURR 0")
gpib.write("CONF:VOLT")
gpib.write("FORM:ELEM VOLT")
time.sleep(1)
def current_mode():
gpib.write("SOUR:FUNC VOLT")
gpib.write("SOUR:VOLT 0")
gpib.write("CONF:CURR")
gpib.write("FORM:ELEM CURR")
time.sleep(1)
def read_old(interval = 0, samples = 1, update_graph = do_nothing):
RAV = 1 << 6
gpib.write("TRIG:COUN 1") # setup trigger count
gpib.write("TRIG:DEL %f" % interval) # setup trigger delay
Time = []
Data = []
CurrentSample = 1
Datum = gpib.readline()
gpib.write("INIT") # start measurement
while CurrentSample <= samples:
reading_available = 0
while not reading_available:
#print str(measurement_event) + ", " + str(reading_available)
time.sleep(interval)
gpib.write("STAT:MEAS?") # read measurement event register
gpib.write("++read 10")
measurement_event = int(gpib.readline())
reading_available = measurement_event & RAV
gpib.write("FETC?")
gpib.write("++read 10")
gpib.write("INIT") # start measurement
Datum = gpib.readline()
#print Datum
#Data = Data + [float(Datum[4:Datum.find(',')])]
Data = Data + [float(Datum)]
Time = Time + [(CurrentSample - 1) * interval]
CurrentSample = CurrentSample + 1
update_graph(Time[-1], Data[-1]) # call graph update function
gpib.write("ARM:COUN INF") # return instrument to live mode
gpib.write("TRIG:DEL 0")
gpib.write("INIT") # start measurements
if samples > 1:
return Time, Data
else:
return float(Datum)
def enable_live_readings():
gpib.write("ARM:COUN INF") # infinite arm count
gpib.write("TRIG:DEL 0") # zero trigger delay
gpib.write("INIT") # start measurements
def disable_voltage_source():
gpib.write("O0X")