QSwitch usage¶

[1]:

import pprint
pp = pprint.PrettyPrinter()
import qcodes
from qcodes_contrib_drivers.drivers.QDevil import QSwitch

Connect via USB:

[3]:

qswitch_addr = '/dev/cu.usbmodem14101'
qswitch = QSwitch.QSwitch('switch', visalib='@py', address=f'ASRL{qswitch_addr}::INSTR')

Connected to: Quantum Machines QSwitch (serial:2, firmware:0.178) in 0.05s

Or connect via Ethernet:

[2]:

qswitch_addr = '192.168.8.21'
qswitch = QSwitch.QSwitch('switch', visalib='@py', address=f'TCPIP::{qswitch_addr}::5025::SOCKET')

Connected to: Quantum Machines QSwitch (serial:2, firmware:0.178) in 0.12s

When the QSwitch is reset, all lines are grounded:

[3]:

qswitch.reset()
qswitch.state()

[3]:

'(@1!0:24!0)'

Or in expanded form:

[4]:

QSwitch.expand_channel_list(qswitch.state())

[4]:

'(@1!0,2!0,3!0,4!0,5!0,6!0,7!0,8!0,9!0,10!0,11!0,12!0,13!0,14!0,15!0,16!0,17!0,18!0,19!0,20!0,21!0,22!0,23!0,24!0)'

Or expressed as a Python array:

[5]:

qswitch.closed_relays()

[5]:

[(1, 0),
 (2, 0),
 (3, 0),
 (4, 0),
 (5, 0),
 (6, 0),
 (7, 0),
 (8, 0),
 (9, 0),
 (10, 0),
 (11, 0),
 (12, 0),
 (13, 0),
 (14, 0),
 (15, 0),
 (16, 0),
 (17, 0),
 (18, 0),
 (19, 0),
 (20, 0),
 (21, 0),
 (22, 0),
 (23, 0),
 (24, 0)]

Beep and blink on SCPI command errors:

[6]:

qswitch.error_indicator('on')

Manipulation by numbers¶

Connect and unground line 23:

[7]:

qswitch.close_relay(23, 9)
qswitch.open_relay(23, 0)
qswitch.state()

[7]:

'(@1!0:22!0,24!0,23!9)'

Tap off line 23 to BNC 2:

[8]:

qswitch.close_relay(23, 2)
qswitch.state()

[8]:

'(@1!0:22!0,24!0,23!9,23!2)'

Multiple relays at once:

[9]:

qswitch.open_relays([(22, 0), (24, 0)])
qswitch.state()

[9]:

'(@1!0:21!0,23!9,23!2)'

Arrangements¶

At a higher level of abstraction, lines and break-out BNCs can be given names.

[10]:

qswitch.arrange(
    breakouts={'DMM': 2, 'VNA': 7},  # BNC 2 connected to DMM & BNC 7 to VNA
    lines={'plunger': 23, 'sensor': 5})  # Give names to lines 23 & 5

There are specialised functions for manipulating relays by name:

[11]:

qswitch.connect('plunger')

which is equivalent to

[12]:

qswitch.close_relay(23, 9)
qswitch.open_relay(23, 0)

that is, connect the device-under-test to input line 23, and then unground it.

For the BNC breakout:

[13]:

qswitch.breakout('sensor', 'DMM')

which is equivalent to

[14]:

qswitch.close_relay(5, 2)
qswitch.open_relay(5, 0)

that is, connect the device-under-test line 5 to BNC 2, and then unground it.

For convenience, the default name of a line or BNC is just its number, so eg.

[15]:

qswitch.breakout('24', '1')

is equivalent to

[16]:

qswitch.close_relay(24, 1)
qswitch.open_relay(24, 0)

Moreover, any breakouts are also disconnected when grounding:

[17]:

qswitch.ground('sensor')

will be equivalent to

[18]:

qswitch.close_relay(5, 0)
qswitch.open_relays([(5, 2), (5, 9)])

Monitors¶

There is a pseudo parameter dedicated to monitoring:

[19]:

qswitch.overview()

[19]:

{'1': ['grounded'],
 '2': ['grounded'],
 '3': ['grounded'],
 '4': ['grounded'],
 'sensor': ['grounded'],
 '6': ['grounded'],
 '7': ['grounded'],
 '8': ['grounded'],
 '9': ['grounded'],
 '10': ['grounded'],
 '11': ['grounded'],
 '12': ['grounded'],
 '13': ['grounded'],
 '14': ['grounded'],
 '15': ['grounded'],
 '16': ['grounded'],
 '17': ['grounded'],
 '18': ['grounded'],
 '19': ['grounded'],
 '20': ['grounded'],
 '21': ['grounded'],
 'plunger': ['connected', 'breakout DMM'],
 '24': ['breakout 1']}

[20]:

monitor = qcodes.Monitor(qswitch.overview)

Autosave¶

When turning on autosave, the state will be restored over restart.

[21]:

qswitch.auto_save('on')
qswitch.auto_save('off')

The QSwitch only supports a single Ethernet connection at a time, so you can explicitly tell Python to let go of the connection:

[ ]:

qswitch.close()