> ## Documentation Index > Fetch the complete documentation index at: https://docs.lagerdata.com/llms.txt > Use this file to discover all available pages before exploring further. # ADC > Read analog-to-digital converter values 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 ```bash theme={null} 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: ```bash theme={null} 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: ```bash theme={null} 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` ```bash theme={null} lager nets add SENSOR_1 adc AIN0 USB0::0x0CD5::0x0007::::INSTR ``` **LabJack U3:** `AIN0`-`AIN15` ```bash theme={null} lager nets add SENSOR_1 adc AIN0 USB0::0x0CD5::0x0003::::INSTR ``` **MCC USB-202:** `CH0`-`CH7` ```bash theme={null} lager nets add SENSOR_1 adc CH0 USB0::0x09DB::0x012B::::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: ```bash theme={null} lager defaults add --adc-net SENSOR_1 ``` Then: ```bash theme={null} lager adc ``` ## Examples ```bash theme={null} # 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 ```bash theme={null} #!/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 adc
` * 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 ` to verify the ADC device is detected ## See Also * [DAC](/source/reference/cli/dac) -- Digital-to-analog converter output (the complement of ADC) * [Python ADC API](/source/reference/python/adc) -- Read ADC values in Python scripts