# Device Support

XClock supports various data acquisition (DAQ) devices for clock generation. This page provides device-specific information, wiring diagrams, and configuration details.

## Supported Devices

### LabJack T4

The LabJack T4 is the primary supported device for XClock.

**Specifications:**

- Base clock frequency: 80 MHz
- Maximum clock frequency: Limited by divisor calculations
- Minimum clock frequency: ~1 Hz

**Advantages:**

- Affordable and widely available
- USB-powered, no external power needed
- Cross-platform support (Windows, macOS, Linux)
- Precise internal clock

#### Wiring Diagram

![LabJack T4 Wiring](../../../resources/labjack_t4_wiring.png)

**Recommended Wiring:**

- **Clock Outputs**: FIO6, FIO7
- **Inputs**: EIO4, EIO5, EIO6, EIO7

#### Available Channels

Query available channels in Python:

```python
from xclock.devices import LabJackT4

t4 = LabJackT4()
output_channels = t4.get_available_output_clock_channels()
print(f"Clock outputs: {output_channels}")
# Output: ('FIO6', 'FIO7')
```

#### Clock Frequency Limitations

The LabJack T4 uses a divisor-based system for generating clocks from the 80 MHz base clock. Not all frequencies are achievable exactly.

**Achievable frequencies:**

- Frequency = 80,000,000 Hz / (divisor × roll_value)
- Divisor: 1, 2, 4, 8, 16, 32, 64, 256
- Roll value: 1-65536

XClock automatically calculates the closest achievable frequency:

```python
channel = t4.add_clock_channel(clock_tick_rate_hz=100, ...)
print(f"Requested: 100 Hz")
print(f"Actual: {channel.actual_sample_rate_hz} Hz")
```

#### Example: Basic LabJack T4 Usage

```python
from xclock.devices import LabJackT4

# Initialize
t4 = LabJackT4()

# Add two synchronized clocks
t4.add_clock_channel(
    clock_tick_rate_hz=60,
    channel_name="FIO6",
    duration_s=10.0,
)

t4.add_clock_channel(
    clock_tick_rate_hz=100,
    channel_name="FIO7",
    duration_s=10.0,
)

# Start and wait
t4.start_clocks(wait_for_pulsed_clocks_to_finish=True)
t4.close()
```

#### Troubleshooting LabJack T4

**Device not found:**

- Install [LabJack LJM software](https://support.labjack.com/docs/ljm-software-installer-downloads-t4-t7-t8-digit)
- Check USB connection
- Test with Kipling software (included with LJM)

**Unexpected frequencies:**

- Check `actual_sample_rate_hz` to see achieved frequency
- Try different target frequencies
- Some frequencies may not be exactly achievable

## Connection Examples

### Single Camera Synchronization

Connect one camera trigger input to LabJack FIO0:

```
LabJack T4          Camera
---------          --------
FIO6     ------>   Trigger In
GND      ------>   Ground
```

### Multi-Camera Setup

Connect multiple cameras to different channels:

```
LabJack T4          Devices
---------          --------
FIO6     ------>   Camera 1 Trigger
FIO7     ------>   Camera 2 Trigger
GND      ------>   Common Ground
```

## Performance Characteristics

### Timing Accuracy

**LabJack T4:**

- Base clock: 80 MHz ± 20 ppm
- Jitter: <1 µs
- Channel-to-channel skew: <100 ns
- Long-term drift: <50 ppm/°C

### Timestamp Resolution

When recording timestamps:

- Resolution: 1 ns (nanosecond)
- Accuracy: Limited by base clock accuracy
- Format: 64-bit signed integer

## Future Device Support

Planned support for additional devices:

- **National Instruments DAQ**: USB-6001, USB-6008, USB-6343
- **LabJack**: U3, T7

```{note}
See {doc}`../developer/adding_devices` for information on adding support for new devices.
```

## See Also

- {doc}`installation` - Installing device drivers
- {doc}`quickstart` - Basic usage examples
- {doc}`../developer/adding_devices` - Adding new device support
- {doc}`../api/devices` - Device API reference