DAC

Control DAC output on box

Control DAC (Digital-to-Analog Converter) output on your device. The DAC command sets a precise analog voltage on a DAC net, useful for generating reference voltages, bias signals, or test stimuli.

Syntax

lager dac [OPTIONS] NET [VOLTAGE]

Global Options

Option	Description
--box TEXT	Lagerbox name or IP address
--help	Show help message and exit

Arguments

• NET - Name of the DAC Net to control
• VOLTAGE - Voltage value in volts to output

Supported Hardware

Manufacturer	Model	Channels	Output Range	Resolution
LabJack	T7	2 (DAC0-DAC1)	0 to 5 V	16-bit
Measurement Computing	USB-202	2 (DAC0-DAC1)	0 to 5 V	12-bit

Channel Naming

When creating DAC nets, the channel name depends on the hardware:

LabJack T7: DAC0, DAC1, or numeric 0, 1

MCC USB-202: DAC0, DAC1, AOUT0, AOUT1, or numeric 0, 1

Default Net

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

lager defaults add --dac-net VOLTAGE_OUTPUT

Then:

lager dac 3.3

Examples

# Set DAC output to 3.3V
lager dac VOLTAGE_OUTPUT 3.3 --box my-lager-box

# Set DAC output to 5.0V
lager dac POWER_RAIL 5.0 --box my-lager-box

# Set DAC output to 1.8V
lager dac REFERENCE_VOLTAGE 1.8 --box my-lager-box

# Set DAC output to 0V
lager dac SIGNAL_GENERATOR 0.0 --box my-lager-box

Troubleshooting

Issue	Cause	Fix
Output stuck at 0V	Net not configured or wrong channel	Verify net configuration with lager nets --box <box>
Voltage inaccurate	Resolution limit or load effects	Both LabJack T7 and USB-202 output 0-5V; verify your circuit doesn’t draw too much current from the DAC output
”Net not found”	Typo or net not created	Check available nets with lager nets --box <box>. Net names are case-sensitive.

Notes

• Net names (e.g., VOLTAGE_OUTPUT, POWER_RAIL) refer to names assigned when setting up your testbed
• Voltage values are specified in volts
• Only works with nets of type dac
• Ensure the target box has DAC nets properly configured
• DAC outputs provide precise voltage control for analog circuits
• Both supported hardware models output 0-5V
• USB-202 channels can be specified as 0-1, DAC0-DAC1, or AOUT0-AOUT1

See Also

• ADC — Analog-to-digital converter input (the complement of DAC)
• Python DAC API — Set DAC output in Python scripts