# Copyright © PyroLab Project Contributors
# Licensed under the terms of the GNU GPLv3+ License
# (see pyrolab/__init__.py for details)
"""
Keysight B2900/BL series SMU
============================
.. admonition:: Dependencies
:class: note
| pyvisa
| NI-VISA *or* pyvisa-py
"""
import time
import pyvisa as visa
from pyrolab import __version__
from pyrolab.drivers import VISAResourceExtensions
from pyrolab.drivers.smu import SMU
[docs]
class B2900(SMU):
"""
Simple network controller class for Keysight B2900 SMU.
This class is used to control the Keysight B2900B/BL SMU. These are not local
devices, nor native PyroLab objects. Therefore, network device
autodetection is not supported.
"""
[docs]
@staticmethod
def detect_devices():
"""
Network device detection not supported.
Becuase SMUs are connected to using the IP address,
this function does not detect them and instead always returns an empty
list.
"""
device_info = []
return device_info
[docs]
def connect(self, address: str = "", timeout: float = 1e3) -> bool:
"""
Connects to and initializes the SMU.
Parameters
----------
address : str
The IP address of the instrument.
timeout : int, optional
The device response timeout in milliseconds (default 1 ms).
Pass ``None`` for infinite timeout.
"""
rm = visa.ResourceManager()
self.device = rm.open_resource(f"TCPIP0::{address}::5025::SOCKET")
self.device.timeout = timeout
self.device.read_termination = "\n"
self.write_termination = "\n"
self.device.ext_clear_status()
self.write("*RST;*CLS")
self.write(":DISP:ENAB ON")
self.device.ext_error_checking()
return True
[docs]
def close(self):
self.device.close()
@property
def timeout(self):
"""
Network timeout duration in milliseconds (errors out if no response
received within timeout).
"""
return self.device.timeout
@timeout.setter
def timeout(self, ms):
self.device.timeout = ms
[docs]
def query(self, message: str = "", delay: float = None):
"""
A combination of :py:func:`write` and :py:func:`read`.
Parameters
----------
message : str
The message to send.
delay : float, optional
Delay in seconds between write and read operations. If None,
defaults to ``self.device.query_delay``.
Raises
------
VI_ERROR_TMO
If there is no data to be read
"""
return self.device.query(message, delay)
[docs]
def write(self, message: str, termination: str = None, encoding: str = None):
"""
Writes a message to the SMU.
Parameters
----------
message : str
The message to send.
termination : str, optional
Alternative character termination to use. If None, the value
of write_termination is used. Defaults to None.
encoding : str, optional
Alternative encoding to use to turn str into bytes. If None,
the value of encoding is used. Defaults to None.
"""
self.device.write(message, termination, encoding)
[docs]
def screenshot(self, path: str, form: str = "PNG"):
"""
Takes a screenshot of the scope and saves it to the specified path.
Image format is PNG.
Parameters
----------
path : str
The local path, including filename and extension, of where
to save the file.
form : str, optional
Format of the created image. Defaults to PNG. Can be JPG, BMP, PNG, or WMF.
"""
instrument_save_path = "'C:\\temp\\Last_Screenshot.png'"
self.write(f"HCOP:SDUM:FORM {form}")
self.wait_for_device()
self.device.ext_error_checking()
self.device.ext_query_bin_data_to_file("HCOP:SDUM:DATA?", str(path))
self.device.ext_error_checking()
[docs]
def write_block(self, message: str):
"""
Writes a message to the scope, waits for it to complete, and checks for errors.
Parameters
----------
message : str
The message to send (not a query).
Notes
-----
This function is blocking.
"""
self.write(message)
self.wait_for_device()
self.device.ext_error_checking()
[docs]
def wait_for_device(self):
"""
Waits for the device until last action is complete.
.. note::
This function is blocking.
"""
self.device.ext_wait_for_opc()
# measure_ and sweep_ not tested yet
[docs]
def measure_current(
self,
voltage: float,
compliance: float,
power_line_cycles: int = 2,
channel: int = 0,
):
"""
Performs a spot measurement of current at the speficied voltage
Parameters
----------
voltage : float
Voltage in Volts
compliance : float
Safety limit on current, in Amps
power_line_cycles : int, optional
Duration of measurement in terms of power line cycles, defaults to 2
channel : int, optional
Channel number, defaults is 1
"""
if channel == 0:
channel = ""
# resets device
self.write("*RST")
# sets source mode to current
self.write(f":SOUR{channel}:FUNC:MODE VOLT")
# sets current
self.write_block(f":SOUR{channel}:VOLT {voltage}")
# sets output protection (current limit)
self.write(f":SENS{channel}:CURR:PROT {compliance}")
# sets measurement range to auto
self.write(f":SENS{channel}:CURR:RANG:AUTO ON")
# turns on voltage sensor
self.write(f':SENS{channel}:FUNC "CURR"')
# sets measurement speed (aperture time)
self.write(f":SENS:CURR:NPLC {power_line_cycles}")
self.device.ext_error_checking()
# turns on source and measurement channel
self.write(":OUTP ON")
# takes measurement
measurement = self.query(":MEAS:CURR? " + (f"(@2)" if channel == 2 else "(@1)"))
# turns off voltage and measurement channel
self.write(":OUTP OFF")
self.device.ext_error_checking()
return measurement
[docs]
def measure_voltage(
self,
current: float,
compliance: float,
power_line_cycles: int = 2,
channel: int = 0,
):
"""
Performs a spot measurement of voltage at the specified current
Parameters
----------
current : float
Current in Amps
compliance : float
Safety limit on voltage, in Volts
power_line_cycles : int, optional
Duration of measurement in terms of power line cycles, defaults to 2
channel : int, optional
Channel number, default is 1
"""
if channel == 0:
channel = ""
# resets device
self.write("*RST")
# sets source mode to current
self.write(f":SOUR{channel}:FUNC:MODE CURR")
# sets current
self.write_block(f":SOUR{channel}:CURR {current}")
# turns on voltage sensor
self.write(f':SENS{channel}:FUNC "VOLT"')
# sets output protection (voltage limit)
self.write(f":SENS{channel}:VOLT:PROT {compliance}")
# sets measurement range to auto
self.write(f":SENS{channel}:VOLT:RANG:AUTO ON")
# sets measurement speed (aperture time)
self.write(f":SENS{channel}:VOLT:NPLC {power_line_cycles}")
self.device.ext_error_checking()
# turns on source and measurement channel
self.write(":OUTP ON")
# takes measurement
measurement = self.query(":MEAS:VOLT? " + (f"(@2)" if channel == 2 else "(@1)"))
# turns off current source and measurement channel
self.write(":OUTP OFF")
self.device.ext_error_checking()
return measurement
[docs]
def toggle_colors(self):
"""
Toggles color scheme of SMU display
"""
color = self.query(":DISP:CSET?")
self.write(":DISP:CSET " + str(int(color) % 2 + 1))
# def sweep_voltage(self, start, stop, steps, compliance, measurement_speed, channel="", log=False):
"""
Staircase sweep measurement of current
Parameters
----------
start : float
Starting voltage
stop : float
Finish voltage
steps : int
Number of steps in meaurement
compliance : float
Sets current limit
measurement_speed : float
Aperture speed in seconds
channel : int, optional
Channel number, defaults to 1
log : bool, optional
Use logarithmic sweep spacing. Defaults to linear
"""
"""
#resets device
self.write("*RST")
#Set sweep source
self.write(f":SOUR{channel}:FUNC:MODE VOLT")
self.write(f":SOUR{channel}:VOLT:MODE SWE")
self.write(f":SOUR:SWE:SPAC " + ("LOG" if log else "LIN"))
self.write(f":SOUR{channel}:VOLT:STAR {start}")
self.write(f":SOUR{channel}:VOLT:STOP {stop}")
self.write(f":SOUR{channel}:VOLT:POIN {steps}")
#set measurement
self.write(f":SENS{channel}:FUNC \"CURR\"")
self.write(f":SENS{channel}:CURR:APER {measurement_speed}")
self.write(f":SENS{channel}:CURR:PROT {compliance}")
#generate triggers
self.write(":TRIG:SOUR AINT")
self.write(f":TRIG:COUN {steps}")
self.device.ext_error_checking()
#enable output
self.write(":OUTP ON")
#begin measurement
self.write_block(":INIT" + (f" (@2)" if channel == 2 else " (@1)"))
#turn off output
self.write(":OUTP OFF")
#read data
measurement = self.query(":FETC:ARR:CURR? " + (f"(@2)" if channel == 2 else "(@1)"))
self.device.ext_error_checking()
return measurement
"""
# def sweep_current(self, start, stop, steps, compliance, measurement_speed, channel="", log=False):
"""
Staircase sweep measurement of voltage
Parameters
----------
start : float
Starting current
stop : float
Finish current
steps : int
Number of steps in meaurement
compliance : float
Sets voltage limit
measurement_speed : float
Aperture speed in seconds
channel : int, optional
Channel number, defaults to 1
log : bool, optional
Use logarithmic sweep spacing. Defaults to linear
"""
"""
#resets device
self.write("*RST")
#Set sweep source
self.write(f":SOUR{channel}:FUNC:MODE CURR")
self.write(f":SOUR{channel}:CURR:MODE SWE")
self.write(f":SOUR:SWE:SPAC " + ("LOG" if log else "LIN"))
self.write(f":SOUR{channel}:CURR:STAR {start}")
self.write(f":SOUR{channel}:CURR:STOP {stop}")
self.write(f":SOUR{channel}:CURR:POIN {steps}")
#set measurement
self.write(f":SENS{channel}:FUNC \"VOLT\"")
self.write(f":SENS{channel}:VOLT:APER {measurement_speed}")
self.write(f":SENS{channel}:VOLT:PROT {compliance}")
#generate triggers
self.write(":TRIG:SOUR AINT")
self.write(f":TRIG:COUN {steps}")
self.device.ext_error_checking()
#enable output
self.write(":OUTP ON")
#begin measurement
self.write_block(":INIT" + (f" (@2)" if channel == 2 else " (@1)"))
#turn off output
self.write(":OUTP OFF")
#read data
measurement = self.query(":FETC:ARR:VOLT? " + (f"(@2)" if channel == 2 else "(@1)"))
self.device.ext_error_checking()
return measurement
` """
