National Instruments 6527 Series User Manual

Chapter 3 Programming
6527 Register-Level Programmer Manual 3-6 ni.com
Input with Filtering
You have the option to set filter enable bits and a filter period before performing input.
The following example enables filtering with an interval of 10 ms for Port 0 (all lines).
To use filtering, set the filter enable bits for the lines you want to filter. Then set a filter
interval, which is common to all lines. The filter interval is in 200 ns increments. To set
a filter interval of 10 ms, the value to write to the Filter Interval Register is 0x00C350
((10 ms/200 ns) = 50,000 decimal = 0x00C350 hexadecimal).
Use the following pseudocode example:
Write (Filter Interval + 2, 0x00) //Set most significant bits of filter interval
Write (Filter Interval + 1, 0xC3) //Set the intermediate bits of filter interval
Write (Filter Interval + 0, 0x50) //Set least significant bits of filter interval
Write (Clear Register, 0x03) //Clear filters and filter interval clock
Write (Port 0 Filter Enables, 0xFF) //Enable filtering for all eight bits of Port 0
Read (Port 0) //Begin reading filtered input
Output
To control an output port of a 6527 device, write a digital value to the appropriate Port
Register to control the solid-state relays associated with that port. At power-up, all solid-state
relays of all output ports are open.
Note
Writing a digital 1 to a port line (which is also the initial power-up state) opens the
relay. Writing a digital 0 to a port line closes the relay, allowing current to flow between
the DIG+ and DIG– terminals of the switch.
The following example writes eight bits—11111110 binary, or 0xFE hexadecimal—to Port 0.
This value closes the solid-state relay on Port 0, line 0, but leaves all other relays in the port
open.
Use the following pseudocode example:
Write (Port 0, 0xFE) //Write 11111110 binary to Port 0

National Instruments 6527 Series Specifications

General

Brand	National Instruments
Model	6527 Series
Category	I/O Systems
Language	English

Summary

Important Information

Warranty Details

Details the warranty period and National Instruments' responsibilities for defective equipment and software media.

Copyright and Legal Notices

Outlines copyright laws, trademark usage, and legal disclaimers regarding the manual and product.

Product Usage Warning

Alerts users to critical safety warnings regarding the use of National Instruments products in life-support systems.

About This Manual

Manual Content Overview

Describes the information contained in the manual for register-level programming of 6527 devices.

Using the Manual Set

Guides users on how to utilize the 6527 Register-Level Programmer Manual alongside other documentation.

Conventions

Document Conventions

Explains the typographical and symbolic conventions used throughout the manual for clarity.

Chapter 1: Getting to Know Your 6527

PCI Interface Overview

Introduces the PCI MITE ASIC used for communication and the need to initialize the PCI interface.

General Operation Registers

Describes the main input/output registers and the Clear Register for resetting functions.

Digital Filtering Option

Explains how to enable/disable filtering to reduce glitches and the use of filter intervals.

Change Notification Option

Details using change notification to generate interrupts on input line changes.

Chapter 2: Register Map and Descriptions

Register Overview

Summarizes register groups: General Operation, Digital Filtering, and Change Notification.

Port Registers (Input/Output)

Describes input registers for optocoupler states and output registers for solid-state relay control.

Key Control Registers

Groups ID, Clear, and Master Interrupt Control Registers for device identification and function management.

Filter and Edge Detection Configuration

Covers registers for setting filter intervals, enabling filtering, and configuring edge detection interrupts.

Status Registers

Details the Change Status Register, which indicates the status of change detection events.

Chapter 3: Programming

Common Terms

Lists and defines terms commonly used in programming examples, such as port addresses and registers.

PCI Initialization

Guides on initializing the PCI local bus and configuring the device for PC and Macintosh systems.

PCI Initialization Examples

Provides pseudocode examples for re-mapping the PCI MITE and activating the device for specific platforms.

Programming Digital I/O Inputs

Explains reading input data from ports and configuring digital filtering for input lines.

Programming Digital I/O Outputs

Details controlling solid-state relays on output ports by writing digital values to port registers.

Change Notification and Interrupts

Covers configuring, handling, and disabling change notification interrupts for input line changes.

Appendix A: Technical Support Resources

Web and Developer Support

Directs users to National Instruments' web support, developer zone, and online resources for assistance.

Customer Education and Training

Provides information on training options, courses, and educational materials for users to enhance skills.

System Integration Services

Offers guidance on consulting or employing system integration services for complex projects and solutions.

Worldwide Support Network

Informs users about National Instruments' global offices and how to contact them for timely support.