> ## Documentation Index
> Fetch the complete documentation index at: https://instro.nominal.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Quickstart
> Drive a simulated power supply end-to-end in about five minutes. No hardware required
## Step-by-step
`instro` ships with a built-in SCPI simulator, so you can try the library without owning any hardware.
```bash theme={null}
pip install instro
```
Open a separate terminal and start the bundled simulator.
```bash theme={null}
python -m instro.psu.scpi_sim_server
```
Create an `InstroPSU` driven by the `SimulatedPSU` driver. The driver owns the VISA transport.
```python theme={null}
from instro.psu import InstroPSU
from instro.psu.drivers import SimulatedPSU
from instro.lib.publishers import FilePublisher
file_pub = FilePublisher(format="jsonl", directory="/tmp/instro/")
psu = InstroPSU(
name="bench_psu",
driver=SimulatedPSU("TCPIP0::127.0.0.1::5025::SOCKET"),
publishers=[file_pub],
num_channels=2,
)
psu.open()
```
```python theme={null}
psu.set_voltage(5.0, channel=1)
psu.set_current_limit(1.0, channel=1)
psu.set_overvoltage_protection_level(5.5, channel=1)
psu.set_overvoltage_protection_enabled(True, channel=1)
psu.output_enable(True, channel=1)
```
Measurement getters return a [Measurement](/library/library#measurements-and-commands) object. Use `.latest` to grab the current value. Every measurement is timestamped, tagged, and streamed to the [Publishers](/library/publishers).
```python theme={null}
voltage = psu.get_voltage(channel=1)
current = psu.get_current(channel=1)
print(f"V: {voltage.latest:.3f} V")
print(f"I: {current.latest:.3f} A")
```
When you're done, disable the output and close the connection. `close()` stops the background daemon and flushes the publishers.
```python theme={null}
psu.output_enable(False, channel=1)
psu.close()
```
All `Commands` and `Measurements` are logged to the `publishers`.
```python theme={null}
print(file_pub.file_path.read_text()) # commands and measurements written to the publisher
```