from pylab_ml.base_instrument import logger
from pylab_ml.collate_instrument import Interface
from pylab_ml.baseclass.base_measurement import Measure
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class Rohde_Schwarz(Measure):
"""Interface to the Keithley SMU Instruments.
The Keithley baseclass can connect to Keithley SMU instruments
Initialization arguments:
addr (int):
interface address
interface (dev_interface.Instrument):
gpib, usbserial
backend (str):
visa backend is either '@ni' for NI-Library or
'@py' for pure python pyvisa-py backend.
On default it uses '@ni' on win32 and '@py' on
other platforms.
Example: Initialization
>>> instrument = Keithley(addr=24) # GPIB or USB address
>>> instrument.init() # connect and initialize instrument
Methods:
init()
connect and initialize
local()
switch back to instrument control
reset()
reset
identify()
instrument message, reflect address & interface
message("")
instrument message ("string") or ()
error_list()
list of instrument errors
close()
terminate interface
com_recover(bool)
detect & attempt to recover out of step communication (maybe after timeout)
inst.write('*RST')
write direct to instrument
ask=inst.query(':READ?')
write and read the answer
Properties:
id get IDN string
"""
interchoices = [Interface.gpib]
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def __init__(self, **kwargs):
self.is_local = False
super().__init__(**kwargs)
logger.debug("Class {}".format(self.__class__.__name__))
self.com._init(self)
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def init(self, identify=False):
"""Connect to Keithley instrument and initialize."""
super().init(identify)
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def reset(self):
"""Reset and switch beep off."""
self.budget.set_slack(self)
self.inst.clear()
self.inst.write(':SYST:BEEP:STAT 0')
self.inst.write('*RST')
self.inst.write(':SYST:BEEP:STAT 0')
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def clear(self):
"""Clear error status."""
self.budget.set_slack(self)
self.inst.clear()
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def error_list(self):
"""List of outstanding errors."""
self.budget.set_slack(self)
errormsgs = self.inst.query(':SYST:ERR:ALL?')
errors = errormsgs.split(",")[1::2]
codes = errormsgs.split(",")[0::2]
errorlist = []
for c, m in zip(codes, errors):
print("{} : {}".format(c, m))
errorlist.append((c, m))
return errorlist
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def message(self, message=None):
"""Message display."""
self.budget.set_slack(self)
if message is None:
self.inst.write(':DISP:TEXT:STAT 0')
else:
linlen = self.msg_row_col[0] * self.msg_row_col[1]
msg = message[:linlen]
self.inst.write(':DISP:TEXT:DATA \"{message}\"'.format(message=msg))
self.inst.write(':DISP:TEXT:STAT 1')
@property
def id(self):
"""Query IDN."""
self.budget.set_slack(self)
try:
value = self.inst.query('*IDN?')
except Exception:
value = ""
return value.replace('\r', '').replace('\n', '')
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def local(self):
"""Switch back to local instrument control."""
self.budget.set_slack(self)
self.inst.write(':SYSTEM:LOC')
self.is_local = True
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def com_recover(self, fix=False):
"""
Can lose coherency between read request and data, usually because of Timeout.
This routine can diagnose such loss of coherency and attempt to fix it, when fix=True
"""
self.budget.set_slack(self)
ires = None
for i in range(1, 10):
self.inst.write(':DISP:TEXT:DATA \"{}\"'.format(i))
res = self.inst.query(':DISP:TEXT:DATA?')
try:
res = "".join([r for r in res if not r in '"'])
ires = int(float(res))
print("For {} got {}".format(i, ires))
if i in [5, 6, 7] and fix:
diff = i - ires
if diff > 0:
print("See offset {}".format(diff))
for j in range(diff):
consume = self.inst.read()
print("Consumed '{}'".format(consume))
except Exception:
print("For {} got: {}".format(i, res))
return (ires == i)