Chapter 2 DAQ System Overview

I/O Connector

 

 

 

 

 

 

 

Isolation

 

 

 

 

 

 

 

 

 

 

 

 

 

Barrier

 

 

 

 

 

 

Analog Input

 

 

 

 

 

 

(USB-6215

 

 

 

 

 

 

 

 

 

 

 

 

 

and USB-6218

 

 

 

 

 

 

 

 

 

 

 

 

 

devices only)

 

 

 

 

 

 

Analog Output

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Digital

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Routing

 

 

Digital

 

Bus

 

 

 

Bus

Digital I/O

 

 

 

 

 

 

 

 

 

 

 

 

and Clock

 

 

Isolators

 

Interface

 

 

 

 

 

 

 

Generation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Counters

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PFI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2-2.USB-621xBlock Diagram

DAQ-STC2

The DAQ-STC2 implements a high-performance digital engine for M Series data acquisition hardware. Some key features of this engine include the following:

•Flexible AI and AO sample and convert timing

•Many triggering modes

•Independent AI, AO, and CTR FIFOs

•Generation and routing of internal and external timing signals

•Two flexible 32-bit counter/timer modules with hardware gating

•Static DI and static DO signals

•USB Hi-Speed 2.0 interface

•Up to four USB Signal Streams for acquisition and generation functions

Calibration Circuitry

The M Series analog inputs and outputs have calibration circuitry to correct gain and offset errors. You can calibrate the device to minimize AI and AO errors caused by time and temperature drift at run time. No external circuitry is necessary; an internal reference ensures high accuracy and stability over time and temperature changes.