DAQ Modules
All Deimos DAQs use unencrypted wired ethernet LAN for communication, and are assigned MAC addresses in the locally-administered block.
This means that untrusted individuals and unrelated hardware should not be given access to the control network.
For more details about networking and security, see the system details.
Multiple DAQ modules can be connected to the same control program; time-synchronization between multiple modules is a first-class feature and typically achieves sub-microsecond average synchronization within a few seconds. See the control program examples for reference programs using several DAQs simultaneously.
Analog I
The Analog I is our flagship DAQ unit, boasting a set of 22 input channels and 6 output channels, all available together and operated simultaneously on every cycle.
Fully open-source, the Analog I's design files, firmware, and control program can all be found under permissive licenses in the Deimos project repository.
Overview
| Feature | Performance |
|---|---|
| Comm. Medium | Ethernet (reliable UDP/IPV4 with full state reassertion) |
| Cycle Rate | 5Hz - 5000Hz, full round-trip control with full state reassertion |
| Multi-Unit Time Sync | ~1 microsecond (100ns typ.) |
| Voltage Reference | 0.02% accuracy, 2.5V |
| ADCs | 16-bit SAR, self-calibrating, 16kHz analog low-pass filter |
| Internal Samplerate | 40kHz burst-scanning w/ synthetic simultaneous sampling |
| Onboard Filtering | Digital Butterworth IIR anti-aliasing filter & Lagrange Polynomial Fractional-Delay FIR sample synchronization filter |
| Supply Voltage | 24V DC |
Outputs
| Kind | Range | Resolution | Notes |
|---|---|---|---|
| 4x PWM/GPIO | 1Hz-400kHz | 16-bit | 3.3V logic. All channels independent frequency and pulse width. |
| 2x DAC (Voltage) | 0-2.5V | 12-bit | Accuracy linked directly to voltage reference (0.02%) |
Inputs
| Kind | Range | Accuracy | Resolution | Notes |
|---|---|---|---|---|
| 4x Voltage, 1x Gain | 0-2.5V | 0.02% | 38uV | Single-ended, 40V tolerance |
| 1x Voltage, 25.7x Gain | 0-97mV | 0.04% | 1.5uV | Single-ended, 40V tolerance |
| 1x Voltage, 660x Gain | 0-3787uV | 0.04% | 58nV | Single-ended, 40V tolerance |
| 2x K-Type Thermocouple | 90-1600K | 0.5K near room temp | 0.03K | Cold-junction compensated. Material-matched connector. |
| 3x 3-Wire Resistance (RTD, strain, etc) | 70-1200K | 0.1K near room temp | 0.02K | Specs refer to use with Pt100 RTD |
| 4x 4-20mA | 0-33mA | 0.04% | 0.8uA | 24V excitation, 2 or 3-wire, short-circuit protected |
| 2x Frequency | 400Hz-1MHz | 100ppm | 16-bit | |
| 1x Pulse Counter | 400Hz-1MHz | N/A | 1 | 64-bit accumulator |
| 1x Encoder | N/A | Signed 64-bit accumulator, forward/backward counting. | ||
| Diagnostics | Bus current, bus voltage, and cold-junction temperature |