Power Supply

Control and monitor power supply Nets through the Lager CLI. Supports multi-vendor bench power supplies with voltage/current setting, protection thresholds, real-time monitoring via TUI, and concurrent access.

Syntax

lager supply [OPTIONS] NET_NAME COMMAND [ARGS]...

When invoked without a subcommand, lists all available power supply nets on the box:

lager supply --box my-lager-box

Name          Net Type       Instrument     Channel  Address
================================================================
PSU_CH1       power-supply   Rigol_DP832    CH1      USB0::0x1AB1::0x0E11::DP8...
PSU_CH2       power-supply   Rigol_DP832    CH2      USB0::0x1AB1::0x0E11::DP8...
DUT_POWER     power-supply   Keysight_E36312A  1     USB0::0x2A8D::0x1602::...

Global Options

Option	Description
`--box TEXT`	Lager Box name or IP address
`--help`	Show help message and exit

Commands

Command	Description
`voltage`	Set or read output voltage with optional protection thresholds
`current`	Set or read output current with optional protection thresholds
`enable`	Enable power output (requires confirmation)
`disable`	Disable power output (requires confirmation)
`state`	Show current power state including measurements and protection status
`clear-ovp`	Clear over-voltage protection fault
`clear-ocp`	Clear over-current protection fault
`set`	Set power supply mode
`tui`	Launch interactive terminal UI for real-time monitoring and control

CLI Validation Ranges

The CLI enforces conservative upper bounds before sending commands to hardware:

Parameter	Maximum	Notes
Voltage	100.0 V	Most bench supplies are 30-60 V
Current	30.0 A	Typical bench supply limit
OVP	110.0 V	Can be slightly above max output
OCP	33.0 A	Can be slightly above max output

All values must be positive. OVP must be greater than or equal to the voltage setpoint.

Command Reference

`voltage`

Set or read output voltage with optional protection thresholds.

lager supply NET_NAME voltage [VALUE] [OPTIONS]

Arguments:

VALUE - Voltage in volts. Omit to read the current voltage setting.

Options:

Option	Type	Description
`--ovp FLOAT`	Volts	Over-voltage protection threshold (must be >= voltage)
`--ocp FLOAT`	Amps	Over-current protection threshold
`--yes`	Flag	Apply without confirmation prompt
`--box TEXT`	String	Lager Box name or IP

When VALUE is provided, the CLI prompts for confirmation unless --yes is passed:

Set voltage to 3.3 V? [y/N]:

Examples:

# Read current voltage
lager supply PSU voltage

# Set voltage to 3.3V (will prompt for confirmation)
lager supply PSU voltage 3.3

# Set voltage with automatic confirmation
lager supply PSU voltage 3.3 --yes

# Set voltage with OVP and OCP thresholds
lager supply PSU voltage 3.3 --ovp 3.6 --ocp 0.5 --yes

`current`

Set or read output current with optional protection thresholds.

lager supply NET_NAME current [VALUE] [OPTIONS]

Arguments:

VALUE - Current in amps. Omit to read the current limit setting.

Options:

Option	Type	Description
`--ovp FLOAT`	Volts	Over-voltage protection threshold
`--ocp FLOAT`	Amps	Over-current protection threshold (must be >= current)
`--yes`	Flag	Apply without confirmation prompt
`--box TEXT`	String	Lager Box name or IP

When VALUE is provided, the CLI prompts for confirmation unless --yes is passed:

Set current to 1.0 A? [y/N]:

Examples:

# Read current limit
lager supply PSU current

# Set current limit to 1A
lager supply PSU current 1.0 --yes

# Set current with protection thresholds
lager supply PSU current 1.0 --ocp 1.2 --ovp 5.0 --yes

`enable`

Enable power output to device. Requires confirmation to prevent accidental power-on.

lager supply NET_NAME enable [OPTIONS]

Options:

Option	Description
`--yes`	Enable without confirmation prompt
`--box TEXT`	Lager Box name or IP

Enable Net? [y/N]:

`disable`

Disable power output. Requires confirmation to prevent accidental power-off.

lager supply NET_NAME disable [OPTIONS]

Options:

Option	Description
`--yes`	Disable without confirmation prompt
`--box TEXT`	Lager Box name or IP

Disable Net? [y/N]:

`state`

Show comprehensive power supply state including measurements, setpoints, and protection status.

lager supply NET_NAME state [--box TEXT]

Example output (Rigol DP800):

Channel: CH1
Enabled: ON
Mode: CV
Voltage: 3.3000
Current: 0.1520
Power: 0.5016
OCP Limit: 1.0000
    OCP Tripped: NO
OVP Limit: 3.6000
    OVP Tripped: NO

Fields:

Channel - Active channel on multi-channel supplies
Enabled - Output ON or OFF
Mode - CV (constant voltage) or CC (constant current)
Voltage/Current/Power - Live measurements (4 decimal places)
OCP/OVP Limit - Protection thresholds
OCP/OVP Tripped - Whether protection tripped (color-coded: green=NO, red=YES)

`clear-ovp`

Clear over-voltage protection fault. Use after an OVP trip to reset the protection and allow the output to be re-enabled.

lager supply NET_NAME clear-ovp [--box TEXT]

`clear-ocp`

Clear over-current protection fault. Use after an OCP trip to reset the protection and allow the output to be re-enabled.

lager supply NET_NAME clear-ocp [--box TEXT]

`set`

Set power supply mode. The available modes depend on the hardware.

lager supply NET_NAME set [--box TEXT]

`tui`

Launch an interactive terminal UI for real-time power supply monitoring and control. The TUI provides live-updating measurements, inline command entry, and keyboard shortcuts.

lager supply NET_NAME tui [--box TEXT]

Requires the textual Python package (pip install textual). TUI display:

Live voltage, current, and power measurements (updated every second)
Output status (ON/OFF) with color coding
Mode indicator (CV/CC) with color coding
Protection thresholds and trip status
Hardware maximum ratings
Scrollable command log

TUI commands (enter at the prompt):

Command	Description
`voltage [VALUE]`	Set or read voltage
`current [VALUE]`	Set or read current limit
`ocp [VALUE]`	Set or read OCP threshold
`ovp [VALUE]`	Set or read OVP threshold
`enable`	Enable output
`disable`	Disable output
`state`	Display current state
`clear-ocp`	Clear OCP trip
`clear-ovp`	Clear OVP trip
`help`	Show available commands
`clear`	Clear the command log
`q` / `quit` / `exit`	Exit the TUI

Keyboard shortcuts:

Key	Action
`q`	Quit
`Ctrl+C`	Quit
`r`	Refresh display
Up/Down arrows	Navigate command history

Concurrent access: While the TUI runs, other lager supply CLI commands (e.g., lager supply PSU voltage 3.3 --yes) will route through the TUI’s WebSocket connection on port 9000. They share the one USB connection to the instrument. If the TUI is not open, commands use direct USB access.

OVP / OCP Protection

Over-voltage protection (OVP) and over-current protection (OCP) thresholds protect your device under test from damage. Setting thresholds:

# Set OVP and OCP when setting voltage
lager supply PSU voltage 3.3 --ovp 3.6 --ocp 0.5 --yes

# Set OCP when setting current
lager supply PSU current 1.0 --ocp 1.2 --yes

Validation rules:

All values must be positive
OVP must be >= the voltage setpoint
OCP must be >= the current setpoint
Values are validated against CLI maximum limits before being sent to hardware

When protection trips:

The supply output is disabled automatically
state shows the tripped status in red
Clear the fault with clear-ovp or clear-ocp
Re-enable the output with enable

Automatic OVP management (Rigol): If a new voltage will exceed the current OVP limit, the driver raises OVP by 10% headroom first. It then sets the new voltage and restores the desired OVP limit. This prevents false trips during voltage changes.

Supported Hardware

Manufacturer	Model Series	Channels	Specs	Notes
Rigol	DP832 / DP832A	3	Ch1-2: 30V/3A, Ch3: 5V/3A	Most common
Rigol	DP821	2	Ch1: 60V/1A, Ch2: 8V/10A
Rigol	DP811 / DP811A	1	20V/10A or 40V/5A (range)
Keithley	2281S	1	20V/6A/120W	Battery simulator mode
Keysight	E36200 series	2	E36233A: 30V/20A per ch	Dual output
Keysight	E36300 series	3	E36311A/12A/13A	Triple output
EA	PSI/EL series	1	PSB 10080-60, PSB 10060-60	Two-quadrant

Multi-channel supplies use the channel number configured in the net record. Each channel is typically configured as a separate net.

Default Net

Set a default power supply net to avoid specifying the name each time:

lager defaults add --supply-net PSU

Then commands can omit the net name:

lager supply voltage 3.3 --yes
lager supply state

Examples

# List all power supply nets
lager supply --box my-lager-box

# Set voltage with protection
lager supply PSU voltage 3.3 --ovp 3.6 --ocp 0.5 --yes

# Set current limit
lager supply PSU current 1.0 --ocp 1.2 --yes

# Enable output (skip confirmation)
lager supply PSU enable --yes

# Check state
lager supply PSU state

# Disable output
lager supply PSU disable --yes

# Clear protection faults
lager supply PSU clear-ovp
lager supply PSU clear-ocp

# Launch interactive TUI
lager supply PSU tui

Scripting Example

#!/bin/bash
# Power cycle a device under test
BOX="my-lager-box"
NET="DUT_POWER"

lager supply $NET voltage 3.3 --ovp 3.6 --ocp 0.5 --yes --box $BOX
lager supply $NET enable --yes --box $BOX
sleep 2

# Run tests while powered
lager python test_script.py --box $BOX

# Power down
lager supply $NET disable --yes --box $BOX

Troubleshooting

Error	Cause	Fix
”Resource busy”	TUI is using the supply’s USB connection	Close the TUI (press `q`), then retry
”No route to host”	Box unreachable	Check VPN/Tailscale: `lager hello --box <box>`
Connection refused	Box service not running	Verify box is online: `lager hello --box <box>`
OVP/OCP validation error	Protection threshold below setpoint	Set OVP >= voltage, OCP >= current
”exceeds maximum limit”	Value above CLI safety limits	Check equipment specs; CLI max is 100V / 30A

Notes

All voltage and current set operations require confirmation (use --yes to skip)
enable and disable also require confirmation
Net names refer to names assigned when setting up your testbed with lager nets
The TUI connects via WebSocket (port 9000) for real-time updates
Protection thresholds help prevent damage to your device under test
Multi-channel supplies: each channel is configured as a separate net

Lager Box Management

Configuration

Power & Simulation

Measurement

I/O & Communication

Development

Utilities

Power Supply

Syntax

Global Options

Commands

CLI Validation Ranges

Command Reference

`voltage`

`current`

`enable`

`disable`

`state`

`clear-ovp`

`clear-ocp`

`set`

`tui`

OVP / OCP Protection

Supported Hardware

Default Net

Examples

Scripting Example

Troubleshooting

Notes

See Also

​Syntax

​Global Options

​Commands

​CLI Validation Ranges

​Command Reference

​voltage

​current

​enable

​disable

​state

​clear-ovp

​clear-ocp

​set

​tui

​OVP / OCP Protection

​Supported Hardware

​Default Net

​Examples

​Scripting Example

​Troubleshooting

​Notes

​See Also

Syntax

Global Options

Commands

CLI Validation Ranges

Command Reference

`voltage`

`current`

`enable`

`disable`

`state`

`clear-ovp`

`clear-ocp`

`set`

`tui`

OVP / OCP Protection

Supported Hardware

Default Net

Examples

Scripting Example

Troubleshooting

Notes

See Also