Editing Data acquisition (section)

===DAQ hardware===

DAQ hardware is what usually interfaces between the signal and a PC. It could be in the form of modules that can be connected to the computer's ports ([[parallel port|parallel]], [[serial port|serial]], [[USB port|USB]], etc.) or cards connected to slots ([[S-100 bus]], AppleBus, ISA, [[Micro Channel architecture|MCA]], PCI, PCI-E, etc.) in a [[motherboard|PC motherboard]] or in a modular crate ([[Computer Automated Measurement and Control|CAMAC]], [[Nuclear Instrumentation Module|NIM]], [[VMEbus|VME]]). Sometimes adapters are needed, in which case an external [[breakout box]] can be used.

DAQ cards often contain multiple components (multiplexer, ADC, DAC, TTL-IO, high-speed timers, RAM). These are accessible via a [[Bus (computing)|bus]] by a [[microcontroller]], which can run small programs. A controller is more flexible than a hard-wired logic, yet cheaper than a CPU so it is permissible to block it with simple polling loops. For example:
Waiting for a trigger, starting the ADC, looking up the time, waiting for the ADC to finish, move value to RAM, switch multiplexer, get TTL input, let DAC proceed with voltage ramp.

Today, signals from some sensors and Data Acquisition Systems can be streamed via Bluetooth.