National Instruments NI 6520 User Manual

Also see for NI 6520: User guide Manual

Contents

National Instruments NI 6520 User Manual Manual pdf 6 page image

NI 6520/6521 User Guide 6 ni.comRelated DocumentationThe following documents contain information that you may find helpful asyou use this user guide:• DAQ Getting Started Guide—This guide describes how to install theNI-DAQ software, the DAQ device, and how to confirm that the deviceis operating properly.• NI-DAQmx Help—This help file contains information about usingNI-DAQmx to program National Instruments devices. NI-DAQmxis the software you use to communicate with and control NI DAQdevices.• Measurement & Automation Explorer Help for NI-DAQmx—Thishelp file contains information about configuring and testing DAQdevices using Measurement & Automation Explorer (MAX) forNI-DAQmx, and information about special considerations foroperating systems.• DAQ Assistant Help—This help file contains information aboutcreating and configuring channels, tasks, and scales using the DAQAssistant.Note You can download these documents from ni.com/manuals.FeaturesDigital FilteringUse the digital filter option available on the NI 6520/6521 input lines toeliminate glitches on input data. When used with change detection, filteringcan also reduce the number of changes to examine and process.You can configure the digital input channels to pass through a digital filterafter the photocouplers, and you can control the timing interval the filteruses. The filter blocks pulses that are shorter than half of the specifiedtiming interval and passes pulses that are longer than the specified interval.Intermediate-length pulses—pulses longer than half of the interval but lessthan the interval—may or may not pass the filter.The filter operates on the inputs from the photocouplers. Photocouplersturn on faster than they turn off and pass rising edges faster than fallingedges. As a result, the photocouplers can add up to 100 μs to a high pulseor subtract up to 100 μs from a low pulse.Note A 100 μs change is typical when IF = 16 mA, and R L = 10 kΩ.