National Instruments PCI-1200 Figure 4-3. Timing Circuitry

Chapter 4 Theory of Operation

PCI-1200 User Manual 4-4 © National Instruments Corporation

Figure 4-3. Timing Circuitry

Each 82C53 contains three independent 16-bit counter/timers and one 8-bit mode register. Each counter has a CLK input pin, a GATE input pin, and an OUT output pin. You can program all six counter/timers to operate in several useful timing modes. The first group of counter/timers is called groupA and includes A0, A1, andA2. You can use these three counters for internal DAQ and DAC

2 MHz

Source

A/D Conversion Logic

1 MHz Source OUTB0

CLKA0

GATEB0

OUTB0

CLKB1

GATEB1

OUTB2

GATEB2

CLKB2

D/A Conversion Logic

82C53 Counter/Timer

Group A

CTR RD

CTR WRT

Data

8

82C53 Counter/Timer

Group B

OUTB0

OUTB2

GATEB2

CLKB2

GATEB1

Scan

Interval/

General

Purpose

Counter

CLKB1

OUTB1

GATEB0

Timebase

Extension/

General

Purpose

Counter

CLKB0

+5 V

MUX

MUX

EXTUPDATE*

EXTTRIG

EXTCONV*

I/O Connector

CLKA2

OUTA0

Sample

Interval

Counter

CLKA0

GATEA0

CLKA1

Sample

Counter

GATEA1

OUTA1

GATEA2

DAC

Timing

OUTA2

General

Purpose

Counter

OUTB1

OUTB1

PCI Bus

Digital

Control

Logic

MITE

PCI

Interface

Chip

Data/Address

Interface Control

Error Reporting

Arbitration

System

Interrupt

1

2

2

2

6

37

Address

Data

Control

Interrupt

1

DRQ

1

4

8

5

Contents

Main Page Important Information Warranty Copyright Trademarks WARNING REGARDING MEDICAL AND CLINICAL USE OF NATIONAL INSTRUMENTS PRODUCTS Contents Chapter 4 Theory of Operation Page Tables About This Manual Organization of This Manual Conventions Used in This Manual National Instruments Documentation Related Documentation Customer Communication Introduction About the PCI-1200 What You Need to Get Started Unpacking Software Programming Choices National Instruments Application Software NI-DAQ Driver Software Register-Level Programming Optional Equipment Custom Cabling Page Installation and Configuration Software Installation Hardware Installation Board Configuration Analog I/O Configuration Analog Output Polarity Analog Input Polarity Analog Input Mode RSE Input (Eight Channels, Reset Condition) NRSE Input (Eight Channels) DIFF Input (Four Channels) Signal Connections I/O Connector Figure 3-1. PCI-1200 I/O Connector Pin Assignments Signal Connection Descriptions Page Page Analog Input Signal Connections Page Types of Signal Sources Floating Signal Sources Ground-Referenced Signal Sources Input Configurations Chapter 3 Signal Connections Table 3-4. Summary of Analog Input Connections Differential Connection Considerations (DIFF Configuration) Differential Connections for Grounded Signal Sources Figure 3-3. Differential Input Connections for G rounded Signal Sources Differential Connections for Floating Signal Sources Figure 3-4. Differential Input Connections for Floating Sources Single-Ended Connection Considerations Single-Ended Connections for Floating Signal Sources (RSE Configuration) Single-Ended Connections for Grounded Signal Sources (NRSE Configuration) Common-Mode Signal Rejection Considerations Analog Output Signal Connections Digital I/O Signal Connections Logical Inputs and Outputs Port C Pin Connections Power Connections DAQ and General Purpose Timing Signal Connections DAQ Timing Connections Page Page Page General Purpose Timing Signal Connections Page Page Chapter 3 Signal Connections PCI-1200 User Manual 3-26 National Instruments Corporation Figure 3-16. General Purpose Timing Signals The GATE and OUT signals in Figure3-16 are referenced to the rising edge of the CLK signal. Timing Specifications Mode 1 Input Timing Mode 1 Output Timing Mode 2 Bidirectional Timing National Instruments Corporation 4-1 PCI-1200 User Manual Theory of Operation This chapter explains the operation of each functional unit of the PCI-1200. Functional Overview The block diagram in Figure4-1 shows a functional overview of the PCI-1200 board. Figure 4-1. PCI-1200 Block Diagram PCI Interface Circuitry Timing Chapter 4 Theory of Operation PCI-1200 User Manual 4-4 National Instruments Corporation Figure 4-3. Timing Circuitry Chapter 4 Theory of Operation National Instruments Corporation 4-5 PCI-1200 User Manual Analog Input Figure 4-4. Analog Input Circuitry Analog Input Circuitry DAQ Operations Controlled Acquisition Mode Freerun Acquisition Mode Interval Scanning Acquisition Mode Single-Channel Data Acquisition Multichannel Scanned Data Acquisition DAQ Rates Analog Output Analog Output Circuitry DAC Timing Digital I/O Page Calibration Calibration at Higher Gains Calibration Equipment Requirements Using the Calibration Function A Specifications Analog Input Input Characteristics Transfer Characteristics Amplifier Characteristics Dynamic Characteristics Stability Explanation of Analog Input Specifications Explanation of Dither Explanation of DAQ Rates Analog Output Output Characteristics Transfer Characteristics Voltage Output Dynamic Characteristics Stability Explanation of Analog Output Specifications Digital I/O Timing I/O Page B Customer Communication Electronic Services Bulletin Board Support FTP Support Fax-on-Demand Support Telephone and Fax Support Country Telephone Fax Technical Support Form Page PCI-1200 Hardware and Software Configuration Form National Instruments Products Other Products Page Documentation Comment Form Title: Edition Date: Part Number: Mail to: Technical Publications Fax to: Technical Publications Glossary Numbers/Symbols A C D E Page L M N O P R S T V W Index A B C D E F G I L M N O R S T U V W