ADC

Read analog-to-digital converter (ADC) values from your box. Supports LabJack T7, LabJack U3 and MCC USB-202 hardware with per-hardware channel naming and voltage ranges.

Syntax

lager adc [NET] [OPTIONS]

Arguments

Argument	Description
`NET`	Name of the ADC net to read (optional if default is set)

Options

Option	Description
`--box TEXT`	Lager Box name or IP address
`--json`	Emit a machine-readable JSON object instead of formatted text
`--help`	Show help message and exit

Usage

Read ADC Value

Read voltage from an ADC net:

lager adc SENSOR_1 --box my-lager-box

Output:

ADC 'SENSOR_1': 2.450000 V

The result is returned in volts with 6 decimal places.

List ADC Nets

When invoked without a net name (and no default is set), lists all available ADC nets:

lager adc --box my-lager-box

Output:

Name            Net Type  Instrument       Channel  Address
================================================================
VOLTAGE_SENSOR  adc       LabJack_T7       AIN0     USB::470026574
TEMP_SENSOR     adc       LabJack_T7       AIN1     USB::470026574
CURRENT_MON     adc       MCC_USB202       CH0      USB0::0x09DB::0x012B::...

Supported Hardware

Manufacturer	Model	Channels	Voltage Range	Input Mode
LabJack	T7	14 (AIN0-AIN13)	+/-10 V	Single-ended
LabJack	U3	16 (AIN0-AIN15)	U3-HV: AIN0-AIN3 +/-10.3 V, AIN4-AIN15 0-2.44 V	Single-ended
Measurement Computing	USB-202	8 (CH0-CH7)	+/-10 V	Single-ended

Hardware Comparison

Feature	LabJack T7	MCC USB-202
Channel count	14	8
Channel names	AIN0-AIN13	CH0-CH7
Pin input format	`0`-`13` or `AIN0`-`AIN13`	`0`-`7` or `CH0`-`CH7`
Voltage range	+/-10 V (bipolar)	+/-10 V (bipolar)
Resolution	16-bit (~0.3 mV/LSB)	12-bit (~4.9 mV/LSB)
Connection	Shared handle (with DAC, GPIO, SPI)	Per-transaction open/close
Device selection	Auto-discovered (no address needed)	Via serial number or VISA address

LabJack U3

The U3 uses a different driver stack from the T7: the LabJack Exodriver and LabJackPython. The two families can share one Lager Box.

The ranges above are LabJack’s figures for a U3-HV. On a U3-HV, AIN0-AIN3 are fixed high-voltage inputs.
AIN4-AIN7 are the same physical pins as FIO4-FIO7, and AIN8-AIN15 are the same pins as EIO0-EIO7. An adc read sets the pin to analog mode, and a gpio read or write on the same pin sets it back to digital mode.
AIN8-AIN15 are on the DB15 connector of the U3.
Lager treats every U3 as a U3-HV, because a U3-LV reports the same USB product ID.

Channel Naming

When you create an ADC net, use a channel name that lager instruments lists for the instrument. lager nets add refuses any other value, including a numeric shorthand such as 0, and prints the valid channels. LabJack T7: AIN0-AIN13

lager nets add SENSOR_1 adc AIN0 USB0::0x0CD5::0x0007::::INSTR

LabJack U3: AIN0-AIN15

lager nets add SENSOR_1 adc AIN0 USB0::0x0CD5::0x0003::::INSTR

MCC USB-202: CH0-CH7

lager nets add SENSOR_1 adc CH0 USB0::0x09DB::0x012B::<SERIAL>::INSTR

Instrument Name Matching

The backend driver is selected based on the instrument name in the net configuration:

Pattern	Driver
`labjack` + `t7` (case-insensitive, flexible separators)	LabJack T7
`labjack` + `u3` (case-insensitive, flexible separators)	LabJack U3
`mcc` + `usb` + `202` (case-insensitive, flexible separators)	MCC USB-202

Default Net

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

lager defaults add --adc-net SENSOR_1

Then:

lager adc

Examples

# Read ADC value from voltage sensor
lager adc VOLTAGE_SENSOR --box my-lager-box

# Read ADC value from temperature sensor
lager adc TEMP_SENSOR --box my-lager-box

# Read ADC value from current monitor
lager adc CURRENT_MONITOR --box my-lager-box

# List all ADC nets on the box
lager adc --box my-lager-box

# Use default net (if configured)
lager adc

Scripting Example

#!/bin/bash
# Read sensor and check threshold
RESULT=$(lager adc VOLTAGE_SENSOR --box my-lager-box)
echo "$RESULT"

# Extract numeric value
VOLTAGE=$(echo "$RESULT" | grep -oP '[\d.]+(?= V)')
if (( $(echo "$VOLTAGE > 3.0" | bc -l) )); then
    echo "Voltage too high: $VOLTAGE V"
    exit 1
fi
echo "Voltage OK: $VOLTAGE V"

Notes

Results are returned in volts with 6 decimal places
The LabJack T7 and the USB-202 support bipolar measurement (+/-10 V range)
On a LabJack U3, only AIN0-AIN3 of a U3-HV are bipolar
ADC nets must be configured before use with lager nets add <name> adc <channel> <address>
Default net can be set with lager defaults add --adc-net
LabJack T7 shares a connection handle with DAC, GPIO, and SPI operations on the same device
USB-202 opens and closes the connection on each read
Use lager instruments --box <box> to verify the ADC device is detected

Lager Box Management

Configuration

Power & Simulation

Measurement

I/O & Communication

Development

Utilities

Syntax

Arguments

Options

Usage

Read ADC Value

List ADC Nets

Supported Hardware

Hardware Comparison

LabJack U3

Channel Naming

Instrument Name Matching

Default Net

Examples

Scripting Example

Notes

See Also

​Syntax

​Arguments

​Options

​Usage

​Read ADC Value

​List ADC Nets

​Supported Hardware

​Hardware Comparison

​LabJack U3

​Channel Naming

​Instrument Name Matching

​Default Net

​Examples

​Scripting Example

​Notes

​See Also

Syntax

Arguments

Options

Usage

Read ADC Value

List ADC Nets

Supported Hardware

Hardware Comparison

LabJack U3

Channel Naming

Instrument Name Matching

Default Net

Examples

Scripting Example

Notes

See Also