AXP/ADC/401 Axon Pico

Silver Honoree - 2024 MAE Innovators Awards

The Axon Pico is an 8-channel flexible ADC, stand-alone data acquisition unit. It supports full-bridge, half-bridge, differential-ended, single-ended, RTD, thermocouple, ICP, and AC coupled measurements, with both voltage and current excitation. Data is packetized directly out of the unit, without the need for a separate chassis. Each unit has two ports, which carry both 100BaseTX Ethernet and power, over CAT5 or better cable. Units can be daisy-chained together, with system synchronization using IEEE 1588 PTP, with each Pico in the chain providing PTP Transparency to downstream units.

For each thermocouple channel, it is necessary to select the Junction Compensation Channel setting. Internally, the AXP/ADC/401 performs linearization for RTD and thermocouple modes.

At the heart of the AXP/ADC/401 is a hard-wired state-machine that oversamples all channels at a rate between 800 ksps and 1.6 Msps and digitally filters any noise above the user-programmable cutoff frequency. This is achieved using cascaded, 15-tap FIR filters with output rate decimation, followed by a final FIR or IIR filter. If IIR filtering mode is selected, the last digital filter in the filtering chain is an 8th or 16th-order (selectable) Butterworth filter. If FIR mode is selected, the last digital filter in the filtering chain is a 49-tap Kaiser window, Beta 6 filter.

All signals are sampled simultaneously. When several channels are sampled at different sampling rates, at the start of an acquisition cycle all channels are aligned.