National Instruments 321906B-01 PXI Interface

Chapter 2 NI2501/2503 Operation

NI 2501/2503 User Manual 2-6

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National Instruments Corporation

• Generate a scanner advanced trigger

• Generate a breakpoint interrupt

You can use the driver software to configure the switch card for continuous

or one-time scanning. In continuous scanning, the switch card cycles

through the scan list until you disable scanning. For one-time scanning, the

switch card cycles through the scan list only once.

You can also use software commands to clear the scan list or reset it to the

beginning at any time.

The onboard control logic for the NI 25 01/2503 switch card gives you

direct access to open and close the relays, and also the capability to

download up to 1024 random scanning instructions. The software included

with the card automatically configures the NI2501/2503 and downloads

the scan list to hardware for you. The scan list itself downloads directly into

the memory of the card to deliver the fastest scan possible with no

controller intervention. You can configure the switch card to process the

scan list once or to continuously loop through the scan list.

When configured to operate as a single switch card with multiple

multiplexers—such as four 6 x 1 two-wire multiplexers—the scan

architecture makes it possible for each multiplexer to have its own parallel

scan list (which must be triggered together). Also, if the switch card is

configured as a matrix, the scanning architecture scans the matrix through

a series of user-definable states.

PXI Interface

The NI2501/2503 switch card has a PXI interface through which you

canuse your driver software to configure and control the card. The

NI2501/2503 takes advantage of PXI features. It uses the PXI TTL triggers

to synchronize scanning with a measurement device such as a National

Instruments NI-4060 PXI digital multimeter (DMM).

Triggers

External Trigger Input

The NI2501/2503 can use an external trigger input to advance between

scan setups in a scan list. Using the driver software, you can configure the

switch card to route the external trigger from any of the PXI TTL trigger

lines, the PXI star trigger, or the EXT TRIG IN pin on the front connector.

Alternatively, you can use a software command to trigger the switch card.

Contents

Main Page Important Information Warranty Copyright Trademarks WARNING REGARDING MEDICAL AND CLINICAL USE OF NATIONAL INSTRUMENTS PRODUCTS Compliance FCC/DOC Radio Frequency Interference Class A Compliance Federal Communications Commission Canadian Department of Communications Conventions Contents Chapter 1 Routing Signals with Your NI 2501/2503 Chapter 2 NI 2501/2503 Operation Appendix A Specifications Page Routing Signals with Your NI2501/2503 About the NI2501/2503 Analog Bus Triggers Cold-Junction Sensor Channel NI 2501 Amplifier Connecting Signals Front Connector Figure 1-1. Front Connector Pinout Assignments for Two-Wire Mode National Instruments Corporation 1-5 NI 2501/2503 User Manual Figure 1-2. Front Connector Pinout Assignments for One-Wire Mode NI 2501/2503 User Manual 1-6 National Instruments Corporation Figure 1-3. Front Connector Pinout Assignments for Four-Wire Mode National Instruments Corporation 1-7 NI 2501/2503 User Manual NI 2501/2503 User Manual 1-8 National Instruments Corporation Figure 1-4. Front Connector Pinout Assignments to Create a 6 x 4 Matrix Page Contact Protection Terminal Blocks Software Choices NI-SWITCH Driver Software National Instruments Application Software Third Party Software NI 2501/2503 Operation Functional Overview Chapter 2 NI2501/2503 Operation Figure 2-1. NI2501 Module Block Diagram NI 2501/2503 User Manual 2-2 Front Connector PXIbus Connector Chapter 2 NI2501/2503 Operation Figure 2-2. NI 2503 Module Block Diagram National Instruments Corporation 2-3 NI 2501/2503 User Manual Multiplexer Two-Wire Mode One-Wire Mode Four-Wire Mode Matrix Mode Switch Control Circuitry Random Scanning PXI Interface Triggers External Trigger Input Scanner Advanced Modes Initiating Scanning Multicard Triggering A Specifications NI 2501 Input Characteristics Transfer Characteristics Channel Amplifier (Unity Gain) Cold-Junction Sensor Channel Amplifier (Unity Gain) Dynamic Characteristics PXI Bus Interface PXI Trigger Bus Power Requirement Physical Environment Shock and Vibration Certifications and Compliances CE Mark Compliance NI 2503 Input Characteristics Transfer Characteristics Dynamic Characteristics PXI Bus Interface PXI Trigger Bus Power Requirement Page B Accessories C Customizing Your Card Current-Loop Receivers Page D Architecture Drawings Appendix D Architecture Drawings Figure D-1. NI 2501 Switch Architecture NI 2501/2503 User Manual D-2 National Instruments Corporation Bank1 BC01 HLSELECT Figure D-2. NI 2503 Switch Architecture National Instruments Corporation D-3 NI 2501/2503 User Manual Bank1 BC01 Bank3 BC23 Common Questions Page F Customer Communication Electronic Services Bulletin Board Support FTP Support Fax-on-Demand Support Telephone and Fax Support Country Telephone Fax Technical Support Form NI 2501/2503 Hardware and Software Configuration Form National Instruments Products Other Products Page Documentation Comment Form Title: NI 2501/2503 User Manual Edition Date : Part Number: 321906B-01 Mail to:Technical Publications Fax to: Technical Publications Glossary Symbols A B C D Page N P R S T V Page Index Numbers A B C G I L M N P Q R S T V