SPI Rack

In this tutorial we explain basic usage of the modular SPI Rack drivers provided by the Qblox instruments package. The driver is based on the programming interface provided by SPI-rack.

In order to connect to the SPI Rack driver:

[1]:

from qblox_instruments import SpiRack

# In our case the SPI Rack is connected to COM port 4
spi = SpiRack('SPI Rack', 'COM4')

Connected to: Qblox SPI Rack (serial:None, firmware:{'device': 'v1.6 - May 10 2019 - mt', 'driver': {'version': '0.3.2', 'date': '21/04/2021-16:38:33', 'hash': '0x94E811E5', 'dirty': False}}) in 0.00s

To verify everything is working correctly we can read out the temperature of the C1b module

[2]:

spi.temperature()

[2]:

23.75

Connecting to S4g

Next, we need to add the modules to our driver. We will be using a S4g module for this tutorial.

[3]:

spi.add_spi_module(2, "S4g")

The S4g module we added can now be accessed through spi.module2. Let’s try setting an output current:

[4]:

spi.module2.dac0.current(1e-3)

This sets the output current of dac0 (output 1) to 1 mA. We can read this current back through:

[5]:

spi.module2.dac0.current()

[5]:

0.0009998321533203139

Now we will change the output range.

[6]:

spi.module2.dac1.span()

[6]:

'range_max_bi'

We see that the span of DAC channel 1 is set to the default 'range_max_bi' (corresponding to -40 to +40 mA), changing this works similar to how we change the current.

[7]:

spi.module2.dac1.span('range_min_bi')
spi.module2.dac1.span()

[7]:

'range_min_bi'

Now we updated the range to the smaller -20 to +20 mA range. We will now set all output values back to zero using the convenient set_dacs_zero function.

[8]:

spi.module2.dac0.current()

[8]:

0.0009998321533203139

[9]:

spi.set_dacs_zero()

[10]:

spi.module2.dac0.current()

[10]:

0.0

Connecting to D5a

Connecting to the D5a module works the same way as the S4g. Instead of the default name module1, let’s give this D5a an alias and call it alice

[11]:

spi.add_spi_module(1, "D5a", "alice")

[12]:

spi.alice.dac0.voltage(1.0)
spi.alice.dac0.voltage()

[12]:

1.0

[13]:

spi.set_dacs_zero()
spi.alice.dac0.voltage()

[13]:

0.0

Similar to the S4g, the D5a also has a span that can be set.

Supported settings are: 'range_4V_uni', 'range_4V_bi' and 'range_2V_bi'.

[14]:

spi.alice.dac0.span()

[14]:

'range_4V_bi'

Extending the SPI module drivers

It is possible to use custom drivers for the SPI modules within the SPI rack driver provided by qblox-instruments. Any class that inherits from SpiModuleBase is accepted by the spi rack driver. The driver can be added as a module by passing a reference to the class instead of the usual string.

As an example, we will add the DummySpiModule to the SPI Rack.

[15]:

from qblox_instruments.qcodes_drivers.spi_rack_modules import DummySpiModule

spi.add_spi_module(3, DummySpiModule, "bob")

Closing the instrument

Finally, we will close the connection to the instrument.

[16]:

spi.close()