"""Baseclass Interfaces to the Keithley SMU Instruments.
:Date: |today|
:Author: Semi-ATE <info@Semi-ATE.org>
"""
from pylab_ml.base_instrument import logger
from pylab_ml.collate_instrument import Interface
from pylab_ml.baseclass.base_measurement import Measure
[docs]
class Keithley (Measure):
"""
Baseclass Interface to the Keithley SMU Instruments.
The Keithley baseclass can connect to Keithley SMU instruments
Methods:
inst.write('*RST')
write direct to instrument
ask=inst.query(':READ?')
write and read the answer
"""
interchoices = [Interface.usbserial, Interface.gpib]
[docs]
def __init__(self, **kwargs):
"""
Connect and initialize Keithley instrument.
Args:
addr (int):
Interface address
interface (Interface):
GPIB, USB
backend (str):
VISA backend is either '@ivi' (or '@ni') for NI-Library or
'@py' for pure python pyvisa-py backend.
On default it uses '@ivi' (or '@ni') on win32 and '@py' on
other platforms.
Example: Initialization
>>> instrument = Keithley(addr=24) # GPIB or USB address
>>> instrument.init() # connect and initialize instrument
"""
self.is_local = False
super().__init__(**kwargs)
logger.debug("Class {}".format(self.__class__.__name__))
self.com._init(self)
[docs]
def init(self, identify=False):
"""
Connect to Keithley instrument and initialize.
Parameters
----------
identify : bool
If True, query the instrument ID and print it to the log.
"""
super().init(identify)
[docs]
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')
[docs]
def clear(self):
"""Clear error status."""
self.budget.set_slack(self)
self.inst.clear()
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def error_list(self):
"""List of instrument 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
[docs]
def message(self, message=None):
"""
Message display about Keithley instrument.
Instrument message ("string") or ()
If message is None, the display is cleared, otherwise the message is shown on the display.
Parameters
----------
message : str or None
Message to be displayed on the instrument. If None, the display is cleared.
"""
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', '')
[docs]
def local(self):
"""Switch back to local instrument control."""
self.budget.set_slack(self)
self.inst.write(':SYSTEM:LOC')
self.is_local = True
[docs]
def com_recover(self, fix=False):
"""
Detect & attempt to recover out of step communication (maybe after timeout).
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
Parameters
----------
fix : bool
If True, attempt to fix out of step communication by consuming extra data from the instrument.
Returns
-------
bool
True if communication is coherent, False otherwise.
"""
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)