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Power API Reference

The Power API provides control over programmable power supplies for Device Under Test (DUT), USB ports, and current measurement through relay 4. Each DUT channel can supply -25V to +25V at up to 2A with precise current monitoring.

Accessing Power​

const power = tester.power;

Power Module Methods​

reset()​

Resets all power supplies to their default state (disabled).

await tester.power.reset();

Returns: Promise<void> / Awaitable[None]

dut(id)​

Access a specific DUT power supply channel.

const dut0 = tester.power.dut(0);

Parameters:

  • id (number / int): DUT channel identifier (0-based)

Returns: Dut instance

usb(id)​

Access a specific USB port for power control and monitoring.

const usb0 = tester.power.usb(0);

Parameters:

  • id (number / int): USB port identifier (0-based, typically 0-1)

Returns: Usb instance

relay_4()​

Access relay 4 for high-precision current measurement.

const relay4 = tester.power.relay_4();

Returns: RelayPower instance

note

This is a special relay with current measurement capability. Current measurement is done using a 0.33 Ohm shunt resistor, providing 1µA resolution up to 500mA.

Dut Class​

Programmable power supply for powering and testing devices.

reset()​

Resets the DUT channel to its default state (disabled).

await dut.reset();

Returns: Promise<void> / Awaitable[None]

configure(config)​

Configures the DUT power supply.

await dut.configure({
  enabled: true,
  target_voltage: 3.3
});

Parameters:

  • config (DutConfiguration):
    • enabled (boolean / bool, optional): Enable or disable the supply
    • target_voltage (number / float, optional): Target voltage (-25 to 25V)

Returns: Promise<DutState> / Awaitable[DutState] - Full state including measured voltage and current

Exceptions:

  • Throws validation error if target_voltage is outside the range [-25, 25]

enable(voltage) / power_up(voltage)​

Enables the DUT power supply at the specified voltage.

await dut.enable(12.0);  // Enable at 12V

Parameters:

  • voltage (number / float): Target voltage (-25 to 25V)

Returns: Promise<DutState> / Awaitable[DutState] - Updated state

Exceptions:

  • Throws validation error if voltage is outside the range [-25, 25]

disable() / power_down()​

Disables the DUT power supply.

await dut.disable();

Returns: Promise<DutState> / Awaitable[DutState] - Updated state with enabled: false

read()​

Reads the complete current state of the DUT supply.

const state = await dut.read();
console.log("Enabled:", state.enabled);
console.log("Target:", state.target_voltage, "V");
console.log("Actual:", state.voltage, "V");
console.log("Current:", state.current, "A");

Returns: Promise<DutState> / Awaitable[DutState] - Full state object

read_current()​

Reads only the current drawn by the DUT.

const current = await dut.read_current();
console.log("Current:", current, "A");

Returns: Promise<number> / Awaitable[float] - Current in amperes

read_voltage()​

Reads only the actual output voltage.

const voltage = await dut.read_voltage();
console.log("Voltage:", voltage, "V");

Returns: Promise<number> / Awaitable[float] - Voltage in volts

Usb Class​

USB port power control with monitoring capabilities.

reset()​

Resets the USB port to its default state (disabled).

await usb.reset();

Returns: Promise<void> / Awaitable[None]

configure(config)​

Configures the USB port power.

await usb.configure({
  enabled: true
});

Parameters:

  • config (UsbConfiguration):
    • enabled (boolean / bool, required): Enable or disable USB power

Returns: Promise<UsbState> / Awaitable[UsbState] - Current state including voltage and current

enable()​

Enables USB port power.

await usb.enable();

Returns: Promise<UsbState> / Awaitable[UsbState] - Updated state with enabled: true

disable()​

Disables USB port power (power cycle).

await usb.disable();

Returns: Promise<UsbState> / Awaitable[UsbState] - Updated state with enabled: false

read()​

Reads the complete current state of the USB port.

const state = await usb.read();
console.log("Enabled:", state.enabled);
console.log("Voltage:", state.voltage, "V");
console.log("Current:", state.current, "A");

Returns: Promise<UsbState> / Awaitable[UsbState] - Full state object

read_current()​

Reads only the current drawn through the USB port.

const current = await usb.read_current();
console.log("USB Current:", current, "A");

Returns: Promise<number> / Awaitable[float] - Current in amperes

read_voltage()​

Reads the USB port voltage.

const voltage = await usb.read_voltage();
console.log("USB Voltage:", voltage, "V");

Returns: Promise<number> / Awaitable[float] - Voltage in volts

RelayPower Class​

Relay 4 with high-precision current measurement capability.

read()​

Reads the complete state including current measurement.

const state = await relay4.read();
console.log("Current through relay:", state.current, "A");

Returns: Promise<RelayState> / Awaitable[RelayState] - State object with current measurement

read_current()​

Reads only the current flowing through the relay.

const current = await relay4.read_current();
console.log("Relay 4 Current:", current, "A");

Returns: Promise<number> / Awaitable[float] - Current in amperes

note

Relay must be closed for current to flow and be measured. Bidirectional current measurement is supported.

Types​

DutState​

{
  enabled: boolean,
  target_voltage: number,  // -25 to 25V
  voltage: number,         // Measured voltage -25 to 25V
  current: number          // Measured current in amperes
}

DutConfiguration​

{
  enabled?: boolean,
  target_voltage?: number  // -25 to 25V
}

UsbState​

{
  enabled: boolean,
  voltage: number,  // Measured voltage
  current: number   // Measured current in amperes
}

UsbConfiguration​

{
  enabled: boolean
}

RelayState​

{
  current: number  // Measured current in amperes
}

Notes​

  • DUT channels support -25V to +25V at up to 2A per channel
  • USB ports provide standard 5V USB power with monitoring
  • Voltage measurements are highly accurate for precise verification
  • Current measurements allow for real-time monitoring and over-current detection
  • Always allow time for voltage stabilization after enable (100-200ms recommended)
  • Use disable() to safely power down before disconnecting devices
  • Relay 4 provides high-precision current measurement (1µA resolution, max 500mA) when closed
  • Monitor current during boot/startup to verify proper device initialization