Data Acquisition System (DAQ)

The headstage chip amplifies and digitizes the electrode signals, so the DAQ handles digital data only: it keeps several streams intact at full rate and synchronizes them with each other and with the GPIO signals.

Three specifications decide what a DAQ can do. Channel capacity is the total number of channels it records, 512 or 1,024 on current systems, and separately how many headstage ports can stream at once. GPIO is which other signals are acquired and synchronized with the neural data — analog inputs such as a photodiode or a treadmill encoder, digital lines from a behavior box or a laser, video frames, stimulation pulses — so that an event is timestamped against a spike by the hardware rather than aligned between two clocks afterwards. Latency is the time from a sample at the headstage to the same sample in the software, about 10 ms on XDAQ, Smartbox and comparable current systems, which sets whether a closed-loop protocol can act on what it sees. Sampling rate, 30 kHz at 16 bits, is set by the headstage chip and matched by the DAQ.

NeuroNexus supplies two systems. XDAQ, engineered and manufactured by Kontex and commercialized by NeuroNexus, acquires X-Series headstages over micro-HDMI in record and record-and-stimulate modes, with Neuropixels probes live, in three models from a 900 g USB-powered unit to a 1,024-channel system that synchronizes video and optogenetic channels with the neural data. Smartbox is built in two configurations, one with four ports for Intan-based headstages and one with a single port to the SiNAPS interface box for SiNAPS active-pixel probes at 1,024+ channels. Both are instruments in Radiens: Allego controls them and shows signal quality during the recording, which is why the DAQ is chosen as part of the recording chain rather than on its own.