Using instro - instro

This page discusses details about using instro.

Instruments

Two ways to get data

You can acquire measurements from an instrument in two ways. The difference is who triggers the reads and how often.

	Background acquisition	On-demand acquisition
How	Call `start()`. A background daemon reads from the instrument at a fixed, configurable rate. Pull the latest N values with `get_channel()` when you need them.	Call read methods (`read_analog()`, `get_voltage()`, …) only when you want a measurement.
Best for	Apps where data should always be available and publishing.	Apps that need measurements only at specific times; lower system and bus load. DMMs are a good example.

open()/close() or `with` block

Instruments can also be open/closed automatically using a with block.

Explicit open() / close()
with block

Best when the instrument’s lifetime spans many functions, or when you want to interleave setup and teardown across event handlers, fixtures, or REPL sessions.

from instro.psu import InstroPSU
from instro.psu.drivers import SimulatedPSU

psu = InstroPSU(
    name="bench_psu",
    driver=SimulatedPSU("TCPIP0::127.0.0.1::5025::SOCKET"),
    num_channels=2,
)
psu.open()

psu.set_voltage(5.0, channel=1)
psu.set_current_limit(1.0, channel=1)
psu.output_enable(True, channel=1)

voltage = psu.get_voltage(channel=1)
print(f"V: {voltage.latest:.3f} V")

psu.output_enable(False, channel=1)
psu.close()

Best for scripts and tests where the instrument is used inside a single scope. close() runs automatically on the way out, even if an exception is raised.

from instro.psu import InstroPSU
from instro.psu.drivers import SimulatedPSU

with InstroPSU(
    name="bench_psu",
    driver=SimulatedPSU("TCPIP0::127.0.0.1::5025::SOCKET"),
    num_channels=2,
) as psu:
    psu.set_voltage(5.0, channel=1)
    psu.set_current_limit(1.0, channel=1)
    psu.output_enable(True, channel=1)

    voltage = psu.get_voltage(channel=1)
    print(f"V: {voltage.latest:.3f} V")

​Instruments

​Two ways to get data

​open()/close() or with block

Instruments

Two ways to get data

open()/close() or `with` block