Tektronix Keithley DAS-4200 Series Function Call Driver Users Guide

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DAS-4200 Series Function Call Driv er

USER’S GUIDE

DAS-4200 Series

Function Call Driver

User’s Guide

Revision B - May 1996

Part Number: 94510

New Contact Information

Keithley Instruments, Inc.

28775 Aurora Road

Cleveland, OH 44139

Technical Support: 1-888-KEITHLEY

Monday – Friday 8:00 a.m. to 5:00 p.m (EST)

Fax: (440) 248-6168

Visit our website at http://www.keithley.com

The information contained in this manual is believed to be accurate and reliable. However, Keithley Instruments, Inc., assumes no responsibility for its use or for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent rights of Keithley Instruments, Inc.

KEITHLEY INSTRUMENTS, INC., SHALL NO T BE LIABLE FOR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES RELATED TO THE USE OF THIS PRODUCT. THIS PRODUCT IS NOT DESIGNED WITH COMPONENTS OF A LEVEL OF RELIABILITY SUITABLE FOR USE IN LIFE SUPPORT OR CRITICAL APPLICATIONS.

Refer to your Keithley Instruments license agreement for speciﬁc warranty and liability information.

All brand and product names are trademarks or registered trademarks of their respective companies.

All rights reserved. Reproduction or adaptation of any part of this documentation beyond that permitted by Section 117 of the 1976 United States Copyright Act without permission of the Copyright owner is unlawful.

Keithley MetraByte Division

Keithley Instruments, Inc.

440 Myles Standish Blvd. Taunton, MA 02780

FAX: (508) 880-0179

Telephone: (508) 880-3000

●

Preface

The DAS-4200 Series Function Call Driver User’s Guide describes how to write programs for DAS-4200 Series boards using the DAS-4200 Series Function Call Driver. The DAS-4200 Series Function Call Driver supports the following DOS-based languages:

●

Microsoft Borland



C/C++ (Version 6.0 and higher)



C/C++ (Version 1.0 and higher)

The DAS-4200 Series Function Call Driver supports the following Windows-based languages:

●

Microsoft C/C++ (Version 7.0 and higher) Microsoft Visual C++ (Version 1.0 and higher)

●

Borland C/C++ (Version 4.0 and higher)

●

Microsoft Visual Basic  for Windows (Version 3.0 and higher)

The manual is intended for programmers using a DAS-4200 Series board in an IBM



PC AT



or compatible computer. It is assumed that users have read the DAS-4200 Series User’s Guide to familiarize themselves with the board’s features, and that they have completed the appropriate hardware installation and conﬁguration. It is also assumed that users are experienced in programming in their selected language and that they are familiar with data acquisition principles.

vii

The DAS-4200 Series Function Call Driver User’s Guide is organized as follows:

●

Chapter 1 contains installation information, a brief description of available functions, and an illustration of the procedures to follow when programming a DAS-4200 Series board using the DAS-4200 Series Function Call Driver. The last section of this chapter explains how to get help.

Chapter 2 contains the background information needed to use the

●

functions included in the DAS-4200 Series Function Call Driver. Chapter 3 contains a programming overview and language-speciﬁc

●

information related to using the DAS-4200 Series Function Call Driver.

●

Chapter 4 contains detailed descriptions of the DAS-4200 Series Function Call Driver functions, arranged in alphabetical order.

Appendix A contains a list of the error codes returned by DAS-4200

●

Series Function Call Driver functions. Appendix B contains instructions for converting counts to v oltage and

●

for converting voltage to counts.

An index completes this manual.

Keep the following conventions in mind as you use this manual:

●

References to DAS-4200 Series boards apply to both the DAS-4201/128K and the DAS-4201/512K boards. When a feature applies to a particular board, that board’s name is used.

●

Unless otherwise noted, references to W indows include W indo ws 3.1, Windows 3.11 for Workgroups, and Windows 95.

●

Keyboard keys and function names are represented in bold typeface.

viii

Table of Contents

Preface

Overview

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

Supporting Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

Technical Reference

Analog-to-Digital Converter (ADC) . . . . . . . . . . . . . . . . . . . . . .2-3

Reference Voltage Range and Vernier Gain . . . . . . . . . . . . . .2-3

Static Conversion Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

Noise Gain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

Dynamic Conversion Errors . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

Channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

Input Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

Onboard Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

Buffer Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

Nonvolatile Memory (EEPROM). . . . . . . . . . . . . . . . . . . .2-9

Host Computer Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

I/O Address Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

Memory Address Space . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

Pacer Clocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

Internal Pacer Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

External Pacer Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

Adjusting the Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

Trigger Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

Software Trigger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

Analog Trigger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

Digital Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18

iii

Trigger Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18

Post-Trigger Acquisition . . . . . . . . . . . . . . . . . . . . . . . . .2-18

About-Trigger Acquisition . . . . . . . . . . . . . . . . . . . . . . . .2-21

Trigger Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24

Equivalent Time Sampling (ETS) . . . . . . . . . . . . . . . . . . . . . . .2-25

Peak Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28

Setup and Installation

Unpacking the Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

Installing the Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

Installing the DAS-4200 Series Standard Software Package .3-2

Installing the ASO-4200 Software Package . . . . . . . . . . . . . .3-3

DOS Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

Windows Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

Conﬁguring the Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

Creating a Conﬁguration File . . . . . . . . . . . . . . . . . . . . . . . . .3-7

Setting Jumpers on the Board . . . . . . . . . . . . . . . . . . . . . . . . .3-9

Setting the Base I/O Address . . . . . . . . . . . . . . . . . . . . . .3-11

Setting the Memory Address . . . . . . . . . . . . . . . . . . . . . .3-12

Excluding the Memory Area . . . . . . . . . . . . . . . . . . . . . .3-13

Setting the Interrupt Level . . . . . . . . . . . . . . . . . . . . . . . .3-14

Setting Trigger Synchronization. . . . . . . . . . . . . . . . . . . .3-15

Setting the Input Impedance for Analog

Input Channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15

Setting the Input Impedance for the Clock

I/O Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17

Setting the Input Impedance for the Trigger

I/O Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-19

Adding a Ground Connection . . . . . . . . . . . . . . . . . . . . .3-20

Installing the Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21

Attaching Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22

Scope and Test Program

Control Keys for D4200.EXE . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1

Scope and Test Program Menus. . . . . . . . . . . . . . . . . . . . . . . . . .4-4

A/D Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4

Display Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

Gates Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9

Options Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

Conﬁguration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

Saving Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-12

Recalling Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-13

Calibrating the DAS-4200 Series Board . . . . . . . . . . . . . . . . . .4-14

Using Parameter Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-15

Troubleshooting

Identifying Symptoms and Possible Causes . . . . . . . . . . . . . . . .5-1

Testing Board and Host Computer. . . . . . . . . . . . . . . . . . . . . . . .5-3

Testing Accessory Slot and I/O Connections. . . . . . . . . . . . . . . .5-4

Technical Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

Speciﬁcations

Keithley Memory Manager

Installing and Setting Up the KMM in Windows 3.x. . . . . . . . . B-2

Using KMMSETUP.EXE . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2

Using a Text Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

Installing and Setting Up the KMM in Windows 95 . . . . . . . . . B-4

Removing the KMM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4

Index

List of Figures

Figure 2-1. DAS-4200 Series Functional Block Diagram . . . .2-1

Figure 2-2. Ideal Transfer Function of a 3-Bit ADC . . . . . . . .2-4

Figure 2-3. Non-Ideal Transfer Function of a 3-Bit ADC . . . .2-5

Figure 2-4. Host Computer Memory Address Space . . . . . . .2-11

Figure 2-5. Analog Trigger Modes. . . . . . . . . . . . . . . . . . . . .2-17

Figure 2-6. Post-Trigger Acquisition . . . . . . . . . . . . . . . . . . .2-19

Figure 2-7. Memory Usage in Post-Trigger Acquisition . . . .2-20

Figure 2-8. About-Trigger Acquisition . . . . . . . . . . . . . . . . .2-22

Figure 2-9. Memory Usage in About-Trigger Acquisition. . .2-23

Figure 2-10. Possible Trigger Position. . . . . . . . . . . . . . . . . . .2-24

Figure 2-11. Trigger Jitter with Synchronized Divider . . . . . .2-24

Figure 2-12. Equivalent Time Sampling (ETS) . . . . . . . . . . . .2-25

Figure 2-13. ETS Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27

Figure 2-14. Peak Detection. . . . . . . . . . . . . . . . . . . . . . . . . . .2-29

Figure 3-1. Jumper Locations. . . . . . . . . . . . . . . . . . . . . . . . .3-10

Figure 3-2. Analog Input Circuitry. . . . . . . . . . . . . . . . . . . . .3-16

Figure 3-3. Clock I/O Connector Circuitry . . . . . . . . . . . . . .3-18

Figure 3-4. Trigger I/O Connector Circuitry . . . . . . . . . . . . .3-19

List of Tables

Table 2-1. Analog Input Ranges . . . . . . . . . . . . . . . . . . . . . . .2-8

Table 2-2. Available Conversion Rates Using

Internal Clock . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

Table 3-1. Configuring DAS-4200 Series Boards . . . . . . . . .3-6

Table 3-2. Base I/O Address . . . . . . . . . . . . . . . . . . . . . . . . .3-11

Table 3-3. Memory Address . . . . . . . . . . . . . . . . . . . . . . . . .3-13

Table 3-4. Interrupt Level Selection . . . . . . . . . . . . . . . . . . .3-14

Table 3-5. Changing the Input Impedance . . . . . . . . . . . . . .3-17

Table 4-1. Control Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

Table 4-2. Suffixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4

Table 4-3. A/D Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5

Table 4-4. Display Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

Table 4-5. Gates Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10

Table 4-6. Options Menu . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

Table 5-1. Troubleshooting Information. . . . . . . . . . . . . . . . .5-1

Table A-1. DAS-4200 Series Specifications . . . . . . . . . . . . . A-1

Table 1-1. Summary of Functions. . . . . . . . . . . . . . . . . . . . . .1-3

Table 2-1. A/D Frame Elements . . . . . . . . . . . . . . . . . . . . . . .2-6

Table 2-2. Analog Input Ranges and Gains . . . . . . . . . . . . .2-10

Table 2-3. Conversion Rates and Sample Periods for the Internal Pacer Clock2-11

Table 3-1. Protected-Mode Memory Architecture . . . . . . . .3-12

Table 4-1. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

Table 4-2. Data Type Prefixes. . . . . . . . . . . . . . . . . . . . . . . . .4-4

Table A-1. Error/Status Codes. . . . . . . . . . . . . . . . . . . . . . . . A-1

Table B-1. Some Span Values For Analog Input Data Conversion Equations B-2

Figure 2-1. Interrupt-Mode Operation . . . . . . . . . . . . . . . . . . .2-5

Figure 2-2. Analog Trigger Conditions . . . . . . . . . . . . . . . . .2-14

Figure 2-3. Digital Trigger Conditions. . . . . . . . . . . . . . . . . .2-15

Figure 4-1. Status Word Settings . . . . . . . . . . . . . . . . . . . . . .4-26

Getting Started

This chapter contains the following sections:

Overview - a description of the DAS-4200 Series Function Call

●

Driver.

Summary of Functions - a brief description of the DAS-4200 Series

●

Function Call Driver functions.

Programming Flow Diagrams - an illustration of the procedures to

●

follow when programming a DAS-4200 Series board using the DAS-4200 Series Function Call Driver.

Getting Help - information on how to get help when installing or

●

using the DAS-4200 Series Function Call Driver.

1-1

Overview

The DAS-4200 Series Function Call Dri ver is a library of data acquisition and control functions (referred to as the Function Call Driver or FCD functions). It is part of the ASO-4200 software package, which includes the following:

Libraries of FCD functions for Microsoft C/C++ and Borland C/C++

●

(for DOS).

●

Dynamic Link Libraries (DLLs) of FCD functions for Microsoft Visual Basic for Windows, Microsoft C/C++ (for Windows), and Borland C/C++ (for Windows).

Support ﬁles, containing program elements, such as function

●

prototypes and deﬁnitions of variable types, that are required by the FCD functions.

Utility programs, running under DOS, that allow you to conﬁgure,

●

calibrate, and test the DAS-4200 Series boards.

●

Language-speciﬁc example programs.

Before you use the Function Call Driver, make sure that you have installed the software, set up the board, and created a conﬁguration ﬁle using the setup and installation procedures described in the DAS-4200

Series User’s Guide .

1-2 Getting Started

Summary of Functions

Table 1-1 provides a brief description of the functions in the DAS-4200 Series Function Call Driver. For more detailed information about the functions, refer to Chapter 4.

Table 1-1. Summary of Functions

Function Type Function Name Description

Initialization K_OpenDriver Initializes any Function Call Driver.

K_CloseDriver Closes a Function Call Driver. K_GetDevHandle Initializes any Keithley DAS board. K_FreeDevHandle Frees a device handle. K_DASDevInit Reinitializes a board.

Operation K_IntStart Starts an interrupt-mode operation.

K_IntStatus Gets the status of an interrupt-mode operation. K_IntStop Stops an interrupt-mode operation.

Frame Management K_GetADFrame Accesses a frame for an analog input operation.

K_FreeFrame Frees a frame. K_ClearFrame Sets all frame elements to their default values.

Memory Management K_IntAlloc Dynamically allocates a memory buffer for an

interrupt-mode operation.

K_IntFree Frees a memory buffer that was dynamically

allocated for an interrupt-mode operation.

K_MoveBufToArray Transfers data from a dynamically allocated

memory buffer to a local integer array.

Buffer Address K_SetBuf Speciﬁes the starting address of a local array

(C/C++) or a dynamically allocated memory buffer (C/C++, Visual Basic for Windows) for an interrupt-mode operation.

K_SetBufI Speciﬁes the starting address of a local array

(Visual Basic for W indo ws) for an interrupt-mode operation.

Summary of Functions 1-3

Table 1-1. Summary of Functions (cont.)

Function Type Function Name Description

Channel and Gain K_SetChn Speciﬁes the channel to use for the operation.

K_SetG Speciﬁes the gain for the speciﬁed channel.

Clock K_SetClk Speciﬁes the pacer clock source.

K_SetClkRate Speciﬁes the clock rate for the internal pacer

clock.

K_GetClkRate Gets the clock rate for the internal pacer clock.

Trigger K_SetTrig Speciﬁes the trigger source.

K_SetADTrig Sets up an external analog trigger. K_SetDITrig Sets up an external digital trigger. K_SetAboutTrig Enables the about trigger and speciﬁes the

number of post-trigger samples.

K_ClrAboutTrig Disables the about trigger.

Miscellaneous K_GetErrMsg Gets the address of an error message string.

K_GetVer Gets revision numbers. K_GetShellVer Gets the current DAS shell version.

Programming Flow Diagrams

This section contains a series of programming ﬂow diagrams illustrating the procedures used when programming each of the operations supported by the DAS-4200 Series Function Call Dri ver. Although error checking is not shown in the ﬂow diagrams, it is recommended that you check the error/status code returned by each function used in your program.

1-4 Getting Started

Preliminary Steps

Install all required ﬁles,

including the function and

variable type deﬁnition ﬁle.

Declare and initialize program

variables.

Initialize the driver

(K_OpenDriver).

Initialize a board

(K_GetDevHandle).

Access a frame

(K_GetADFrame).

Using another

board?

For each board, perform the remaining

steps appropriate to the analog input

operation (beginning on the next page).

Yes

Programming Flow Diagrams 1-5

Steps for an Analog Input Operation

Continued from previous page

How is

memory to be

allocated?

Dynamically allocated memory buffer

Allocate a buffer

(K_IntAlloc).

Specify the starting address of the buffer

(K_SetBuf).

Specify the channel to use

(K_SetChn).

Specify the gain

for the channel

(K_SetG).

Local array

Declare and dimension

a local array.

Specify the starting

address of the local

array (K_SetBufI).

What type

of clock

source?

Specify an external pacer clock source

(K_SetClk) and set up the external clock

(hardware setup).

Continued on next page

Internal

External

Speciﬁy an internal clock

source (K_SetClk).

Set the clock rate

(K_SetClkRate).

1-6 Getting Started

Steps for an Analog Input Operation (cont.)

Continued from previous page

Using a trigger?

Specify an internal

start trigger

(K_SetTrig)l

Yes

What type of

Specify an external start

trigger (K_SetTrig)

What type of

external start

Specify digital trigger

conditions (K_SetDITrig)

trigger?

External start trigger.

trigger?

Digital

About trigger

Analog

Specify an internal

start trigger (K_SetTrig)l

Continued on next page

Specify the

analog

trigger conditions

Disable the

about trigger

(K_ClrAboutTrig)

Specify the number of

Delaying

data

collection?

Yes

post-trigger delay samples

(K_SetPostTrigDelay)

Go to page 1-9

Programming Flow Diagrams 1-7

Steps for an Analog Input Operation (cont.)

Continued from previous page

When reading

data?

Only before about trigger occurs

Enable the about trigger

and specify 1 sample

(K_SetAboutTrig)

What type

of about

trigger?

Digital

Before and after the about trigger occurs

Analog

Enable the about trigger

and specify the number of

post-trigger samples

(K_SetAboutTrig)

Specify the analog

about trigger conditions

(K_SetADTrig)

Specify digital

about trigger

conditions

(K_SetDITrig)

Continued on next page

1-8 Getting Started

Steps for an Analog Input Operation (cont.)

Continued from previous page or from page 1-7

Start the operation

(K_IntStart)

Monitor the status of the operation

(K_IntStatus)

Stop the operation

(K_IntStop)

Which

programming

language?

Visual Basic for Windows

Transfer data from the buffer to a

local array (K_MoveBufToArray)

Read data from the array

Convert data

from the array

Free the frame

K_FreeFrame

Operation complete

C / C++

Read data

from the buffer

Convert data

from the buffer

Free the buffer

(K_IntFree)

Programming Flow Diagrams 1-9

Getting Help

If you need help installing or using the DAS-4200 Series Function Call Driver, call your local sales ofﬁce or call the following number for technical support:

(508) 880-3000

Monday - Friday, 8:00

A.M.

- 6:00

P.M.

, Eastern Time

An applications engineer will help you diagnose and resolve your problem over the telephone.

Please make sure that you have the information on the following page available before you call.

1-10 Getting Started

DAS-4200Series board conﬁguration

Computer

Operating system

Software package

Compiler (if applicable)

Model Serial # Revision code Base address setting Interrupt level setting Input conﬁguration Input range type

Manufacturer CPU type Clock speed (MHz) Amount of RAM Video system BIOS type

DOS version Windows version

Name Serial # Version Invoice/Order #

Language Manufacturer Version

_____________________ _____________________ _____________________ _____________________ _____________________ single-ended, differential unipolar, bipolar

_____________________ _____________________ _____________________ _____________________ _____________________ _____________________

_____________________ _____________________

_____________________ _____________________ _____________________ _____________________

_____________________ _____________________ _____________________

Accessories

Getting Help 1-11

Type/Number Type/Number Type/Number Type/Number Type/Number Type/Number Type/Number Type/Number

_____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________

Available Operations

This chapter contains the following sections:

System Operations - descriptions of the miscellaneous operations

●

and general maintenance operations that apply to DAS-4200 Series boards and to the DAS-4200 Series Function Call Driver.

Analog Input Operations - description of the operation mode

●

available for analog input operations and instructions for allocating memory and setting parameters for an analog input operation.

2-1

System Operations

Initializing the Driver

This section describes the miscellaneous operations and general maintenance operations that apply to DAS-4200 Series boards and to the DAS-4200 Series Function Call Driver. It includes information on initializing a driver, initializing a board, retrieving revision levels, and handling errors.

You must initialize the DAS-4200 Series Function Call Driver and any other Keithley D AS Function Call Dri v ers you are using in your program. T o initialize the dri v ers, use the K_OpenDriver function. Y ou specify the driver you are using and the conﬁguration ﬁle that deﬁnes the use of the driver . The driv er returns a unique identiﬁer for the driv er; this identiﬁer is called the driver handle.

You can specify a maximum of 30 driver handles for all the Keithley MetraByte drivers initialized from all your programs. If you no longer require a driver and you want to free some memory or if you ha ve used all 30 driver handles, you can use the K_CloseDriver function to free a driver handle and close the associated driver.

If the driver handle you free is the last driver handle speciﬁed for a Function Call Driver, the driver is shut down. (For Windows-based languages only, the DLLs associated with the Function Call Driver are shut down and unloaded from memory.)

Initializing a Board

The DAS-4200 Series Function Call Driver supports up to two boards. You must use the K_GetDevHandle function to specify the boards you want to use. The driver returns a unique identiﬁer for each board; this identiﬁer is called the device handle.

Device handles allow you to communicate with more than one board. You use the device handle returned by K_GetDevHandle in subsequent function calls related to the board.

2-2 Available Operations

You can specify a maximum of 30 device handles for all the Keithley MetraByte boards accessed from all your programs. If a board is no longer being used and you want to free some memory or if you have used all 30 device handles, you can use the K_FreeDevHandle function to free a device handle.

Use K_GetDevHandle the ﬁrst time you initialize a board only. Once you have a device handle, you can reinitialize a board as needed by using the K_DASDevInit function.

Retrieving Revision Levels

If you are using functions from different Keithley DAS Function Call Drivers in the same program or if you are having problems with your program, you may want to verify which versions of the Function Call Driver, Keithley DAS Driver Speciﬁcation, and Keithley DAS Shell are installed on your computer.

The K_GetVer function allows you to get both the revision number of the DAS-4200 Series Function Call Driver and the revision number of the Keithley DAS Driver Speciﬁcation to which the driver conforms.

The K_GetShellVer function allows you to get the revision number of the Keithley DAS Shell (the Keithley DAS Shell is a group of functions that are shared by all DAS boards).

Handling Errors

Each FCD function returns a code indicating the status of the function. To ensure that your program runs successfully, it is recommended that you check the returned code after the execution of each function. If the status code equals 0, the function executed successfully and your program can proceed. If the status code does not equal 0, an error occurred; ensure that your program takes the appropriate action. Refer to Appendix A for a complete list of error codes.

System Operations 2-3

Each supported programming language uses a different procedure for error checking. Refer to the following for information:

C/C++ page 3-5 Visual Basic for Windows page 3-14

For C-language programs only, the DAS-4200 Series Function Call Driver provides the K_GetErrMsg function, which gets the address of the string corresponding to an error code.

Analog Input Operations

This section describes the following:

●

Operation Mode

DAS-4200 Series boards support interrupt mode only. In interrupt mode, the board acquires multiple samples from a single analog input channel. A hardware clock initiates A/D conversions. Once the analog input operation begins, control returns to your program. The hardware continues to store the acquired data in its onboard memory until the speciﬁed number of samples is acquired, then transfers the data all at once to a user-deﬁned buf fer in the computer using an interrupt service routine.

Use the K_IntStart function to start an analog input operation in interrupt mode. Use the K_IntStop function to stop the operation. Use the K_IntStatus function to determine the current status of the operation.

The converted data is stored as counts. For information on converting counts to voltage, refer to Appendix B.

Analog input operation mode available. How to allocate and manage memory for analog input operations. How to specify the following for an analog input operation: a

channel, a gain and range, a clock source, a trigger source, and the trigger acquisition type.

2-4 Available Operations

Frames

The DAS-4200 Series Function Call Driver uses frames to perform interrupt-mode analog input operations. A frame is a data structure whose elements deﬁne the attributes of the operation. For each board you are using in a program, use the K_GetADFrame function to access an analog input frame, called an A/D (analog-to-digital) frame. The driver returns a unique identiﬁer for the frame; this identiﬁer is called the frame handle.

Specify the attributes of the operation by using a separate setup function to deﬁne each element of the A/D frame. Use the frame handle returned by the driver in each setup function to ensure that you always deﬁne the same operation. For example, assume that you access an A/D frame with the frame handle ADFrame. To specify the channel on which to perform the operation, use the K_SetChn setup function, referencing the frame handle ADFrame. To specify the gain at which to read the channel, use the K_SetG setup function, also referencing the frame handle ADFrame.

When you are ready to perform the operation you have set up, use the

K_IntStart function to start the operation, again referencing the

appropriate frame handle. Figure 2-1 illustrates the use of an A/D frame for an interrupt-mode operation, where the frame handle is ADFrame.

K_IntStart (ADFrame)

ADFrame

Channel Clock Source Trigger Source

. . .

Figure 2-1. Interrupt-Mode Operation

Attributes of Operation

Analog input channel Pacer clock source Trigger source

. . .

Analog Input Operations 2-5

Frames help you create structured programs. They are useful for operations that have many deﬁning attributes, since providing a separate argument for each attribute could make a function’s argument list unmanageably long.

If you want to perform an interrupt-mode operation and all frames have been accessed, you can use the K_FreeFrame function to free a frame that is no longer in use. You can then redeﬁne the elements of the frame for the next operation.

When you access a frame, the elements are set to their default values. You can also use the K_ClearFrame function to reset all the elements of a frame to their default values.

Table 2-1 lists the elements of an A/D frame, the default value of each element, the setup function used to deﬁne each element, and the pages in this guide on which to ﬁnd information speciﬁc to the function.

Table 2-1. A/D Frame Elements

Element Default Value Setup Function See Also

Buffer

Number of Samples 0 K_SetBuf page 4-37

Channel 0 K_SetChn page 4-41 Gain 0 (gain of 1) K_SetG page 4-47 Clock Source Internal A/D pacer clock K_SetClk page 4-42 Pacer Clock Rate Trigger Source Internal K_SetTrig page 4-49 Trigger Type Digital K_SetADTrig page 4-35

Trigger Channel 0 (for analog trigger) K_SetADTrig page 4-35

0 (NULL) K_SetBuf page 4-37

K_SetBufI page 4-39

0 K_SetClkRate page 4-43

K_SetDITrig page 4-45

0 (for digital trigger) Not applicable

page 4-45

2-6 Available Operations

Table 2-1. A/D Frame Elements (cont.)

Element Default Value Setup Function See Also

Trigger Polarity Positive K_SetADTrig page 4-35

K_SetDITrig page 4-45

Trigger Sensitivity Edge (for analog) K_SetADTrig page 4-35

Edge (for digital) Not applicable

Trigger Level 0 K_SetADTrig page 4-35

page 4-45

About-Trigger Acquisition

Notes

This element must be set.

The default value of this element cannot be changed.

Use this function to reset the value of this particular frame element to its default setting

without clearing the frame or getting a new frame. Whene v er you clear a frame or get a ne w frame, this frame element is set to its default value automatically.

Disabled K_SetAboutTrig page 4-33

K_ClrAboutTrig

Memory Allocation and Management

Interrupt-mode analog input operations require a memory buffer in which to store acquired data. DAS-4201/128K boards can acquire 131,072 samples (128K); DAS-4201/512K boards can acquire 524,288 samples (512K).

Note:

board requires, it is recommended that you allocate a maximum buffer size of 128K for DAS-4201/128K boards and 512K for DAS-4201/512K boards.

Even though you can allocate a memory buffer greater than the

page 4-7

The ways you can allocate and manage memory are described in the following sections.

Analog Input Operations 2-7

Dynamically Allocating a Memory Buffer

You can allocate a memory buffer dynamically outside of your program’ s memory area. This way is recommended for the D AS-4200 Series boards. The advantages of this method are as follows:

●

The size of the buffer is limited by the amount of free physical memory available in your computer at run time.

A dynamically allocated memory buffer can be freed to make it

●

available to other programs or processes.

Use the K_IntAlloc function to dynamically allocate a memory buffer. You specify the operation requiring the buffer and the number of samples to store in the buffer. The driver returns the starting address of the buffer and a unique identiﬁer for the buffer; this identiﬁer is called the memory handle. When the buffer is no longer required, you can free the buffer for another use by specifying this memory handle in the K_IntFree function.

For Visual Basic for Windows, data in a dynamically allocated buffer is not directly accessible to your program. You must use the

K_MoveBufToArray function to move the data from the dynamically

allocated buffer to the program’s local array; refer to page 4-30 for more information.

Notes:

If you are writing W indows 95, 32-bit programs, you must install

the Keithley Memory Manager. See your board user’s guide for details.

For DOS-based languages, the area used for dynamically allocated memory buffers is referred to as the far heap; for Windows-based languages, this area is referred to as the global heap. These heaps are areas of memory left unoccupied as your program and other programs run.

For DOS-based languages, the K_IntAlloc function uses the DOS Int 21H function 48H to dynamically allocate far heap memory. For Windows-based languages, the K_IntAlloc function calls the

GlobalAlloc API function to allocate the desired buffer size from the

global heap.

For Windows-based languages, dynamically allocated memory is guaranteed to be ﬁxed and locked in memory.

2-8 Available Operations

Dimensioning a Local Array

A simpler way to reserve a memory location is to dimension an array within your program’s memory area. The adv antage of this method is that the array is directly accessible to your program. The limitations of this method are as follows:

●

Certain programming languages limit the size of local arrays. Local arrays occupy permanent memory areas; these memory areas

●

cannot be freed to make them available to other programs or processes.

●

You cannot use local arrays with Windows 95, 32-bit programs.

Because of these limitations and because the DAS-4200 Series boards can store up to 524,288 samples onboard, dimensioning a local array is not recommended.

Since the DAS-4200 Series Function Call Driver stores data in 16-bit integers, you must dimension all local arrays as integers.

Assigning the Starting Address

After you allocate a buffer or dimension an array, you must assign the starting address of the array or buffer and the number of samples to store in the buffer or array. Each supported programming language requires a particular procedure for assigning a starting address. Refer to the following table for information:

Language Memory Location Function Refer to

C/C++ Array or Buffer K_SetBuf page 3-4 Visual Basic for

Windows

Array K_SetBufI page 3-11 Buffer K_SetBuf page 3-10

Analog Input Operations 2-9

Channels

DAS-4200 Series boards provide tw o analog input channels; the software refers to Channel A as channel 0 and Channel B as channel 1. You can perform an analog input operation on a single channel at a time. To acquire samples from both channels, you must alternate between the two channels after an acquisition is done.

You can acquire a single sample or multiple samples from a single analog input channel. Use the K_SetChn function to specify the channel.

Gains and Ranges

Each channel on the DAS-4200 Series board can measure signals in one of eight, software-selectable bipolar analog input ranges.

Table 2-2 lists the analog input ranges supported by DAS-4200 Series boards and the gain and gain code associated with each range. Use the

K_SetG function to specify the gain code (the gain code is used by K_SetG to represent the gain).

Table 2-2. Analog Input Ranges and Gains

Analog Input

Range

±2 V 1 0

±1 V 2 1

±500 mV 4 2

±250 mV 8 3

±125 mV 16 4

±62.5 mV 32 5

±31.25 mV 64 6

±15.625 mV 128 7

Gain

Gain Code

2-10 Available Operations

Pacer Clocks

The pacer clock determines the period between A/D conversions. You can specify an internal or an external pacer clock, as described in the following subsections. Refer to the DAS-4200 Series User’s Guide for more information.

Internal Pacer Clock

The internal pacer clock is the 100-MHz oscillator on the DAS-4200 Series board. The default clock source is internal; to reset the clock source to the internal clock, use the K_SetClk function.

When you start an analog input operation (using K_IntStart ), conversions are performed at a rate of 3.2 Gsamples/s divided by a clock divider value. Use the K_SetClkRate function to specify the clock divider value. Table 2-3 lists the supported clock divider values and the corresponding conversion rates and sample periods for the internal pacer clock.

Table 2-3. Conversion Rates and Sample Periods

for the Internal Pacer Clock

Clock Divider

32 100 Msamples/s 10 ns 64 50 Msamples/s 20 ns 128 25 Msamples/s 40 ns 256 12.5 Msamples/s 80 ns 512 6.25 Msamples/s 160 ns 1024 3.13 Msamples/s 320 ns 2048 1.56 Msamples/s 640 ns 4096 0.78 Msamples/s 1280 ns

Analog Input Operations 2-11

Conversion Rate

Sample Period

Note:

Table 2-3, the driver uses the next fastest rate. For example, if you enter a clock divider value of 63, the driver uses a clock divider value of 32 to perform the faster conversion rate. To determine the actual clock divider value used, use the K_GetClkRate function.

External Pacer Clock

You connect an external clock to the Clock I/O connector of the DAS-4200 Series board. To specify an external clock source, use the

K_SetClk function.

When you start an analog input operation (using K_IntStart ), conversions are armed. At the next rising edge of the external pacer clock (and at every subsequent rising edge of the external pacer clock), a conversion is initiated.

Triggers

A trigger is an event that occurs based on a speciﬁed set of conditions. The operation must have a start trigger that determines when the acquisition starts. In addition, you can choose the optional about trigger to determine when the acquisition stops.

If you enter a clock divider value that is not one of those listed in

You can deﬁne operations that acquire data after the trigger event occurs (post-trigger acquisition), operations that acquire data before a trigger event (pre-trigger acquisition), and operations that acquire data before and after a trigger event (about-trigger acquisition). If you specify an about trigger, the operation stops when a speciﬁed number of samples has been acquired after the occurrence of the about-trigger event.

The following sections describe the supported trigger sources and the ways to acquire data using triggers.

2-12 Available Operations

Trigger Sources

You can specify an internal or an external trigger source. An internal trigger is a software trigger . External triggers can be either analog triggers or digital triggers. The trigger event is not signiﬁcant until the operation the trigger governs has been started (using K_IntStart ).

The internal trigger, external analog trigger, and external digital trigger are described in the following subsections.

Internal T rigger

An internal trigger is a software trigger. The trigger event occurs when you start the operation using the K_IntStart function. Note that there is a slight delay between the time you start the operation and the time the trigger event occurs.

The internal trigger is the default trigger source. To reset the trigger source to internal, use the K_SetTrig function.

External Analog Trigger

You can use the signal on the analog input channel being sampled as the trigger signal for an analog trigger. The trigger conditions for analog triggers are illustrated in Figure 2-2 and described as follows:

● Positiv e-Edge Trigger - A trigger event occurs the ﬁrst time the

trigger signal changes from a voltage that is less than the trigger level to a voltage that is greater than the trigger level.

● Negative-Edge Trigger - A trigger event occurs the ﬁrst time the

trigger signal changes from a voltage that is greater than the trigger level to a voltage that is less than the trigger level.

● Positiv e-Level Trigger - A trigger event occurs the ﬁrst time the

trigger signal is a voltage that is greater than the trigger level.

● Negative-Lev el Trigger - If the trigger polarity is negative and the

sensitivity is level, a trigger event occurs the ﬁrst time the trigger signal is a voltage that is less than the trigger level.

Analog Input Operations 2-13

Positive-level trigger occurs

Level + 5 V

0 V

Negative-edge or negative-level trigger occurs

Analog input operation start function is executed

Positive-edge trigger occurs

Figure 2-2. Analog Trigger Conditions

To specify an external analog trigger, ﬁrst use the K_SetTrig function to specify an external trigger. Then, use the K_SetADTrig function to specify the analog input channel to use as the trigger channel, the trigger level, and the trigger polarity and sensiti vity. You specify the trigger level as a count value.

Refer to Appendix B for information on how to convert a voltage to a count value.

External Digital Trigger

The digital trigger signal is connected to the Trigger I/O connector of the DAS-4200 Series boards. To specify an external digital trigger, ﬁrst use the K_SetTrig function to specify an external trigger. Then, use the K_SetDITrig function to specify whether you want the trigger event to occur on the rising edge of the digital trigger signal (positive-edge trigger) or on a falling edge of the digital trigger signal (negative-edge trigger). The trigger events are illustrated in Figure 2-3.

2-14 Available Operations

Trigger Acquisition

The ways you can acquire data using triggers are described in the following subsections.

Post-Trigger Acquisition

Use post-trigger acquisition in applications where you want to collect data after a speciﬁc trigger event. You specify a start trigger only; the start trigger determines when the operation starts and can be either an internal, an external analog, or an external digital trigger. To stop the operation, use the K_IntStop function.

Negative-edge

trigger event occurs Positive-edge trigger event occurs

Trigger signal

Figure 2-3. Digital Trigger Conditions

To specify post-trigger acquisition, perform the following steps:

1. Specify the start trigger.

– Use K_SetTrig to specify an internal or an external trigger

source (specify external for an analog or digital trigger).

– If you specify an external start trigger in K_SetTrig, deﬁne the

start trigger conditions using K_SetADTrig (for an analog trigger) or K_SetDITrig (for a digital trigger).

2. If you speciﬁed an external analog or digital start trigger, use

K_ClrAboutTrig to disable the about trigger.

Analog Input Operations 2-15

Pre-Trigger Acquisition

Use pre-trigger acquisition in applications where you want to collect data before a speciﬁc trigger event. The start trigger is always an internal trigger; the operation starts when your program calls the K_IntStart function. The operation stops when the about-trigger event occurs. The about trigger can be either an external analog or external digital trigger.

To specify pre-trigger acquisition, perform the following steps:

1. Use K_SetTrig to specify an internal start-trigger source.

2. Use K_SetAboutTrig to enable the about trigger and to set the

number of samples to 1.

Note: The minimum number of samples that you can specify in

K_SetAboutTrig is 1.

3. Specify the trigger conditions for the about trigger. – If the about trigger is an external analog trigger, use

K_SetADTrig to specify the trigger conditions for the about trigger.

– If the about trigger is an external digital trigger, use K_SetDIT rig

to specify the trigger conditions for the about trigger.

About-Trigger Acquisition

Use about-trigger acquisition in applications where you want to collect data both before and after a speciﬁc trigger event. The start trigger is always an internal trigger; the operation starts when your program calls the K_IntStart function. The operation stops after a speciﬁed number of samples has been acquired after the about-trigger event occurs. The about trigger can be either an external analog or external digital trigger.

To specify about-trigger acquisition, perform the following steps:

1. Use K_SetTrig to specify an internal start-trigger source.

2. Use K_SetAboutTrig to enable the about trigger and to specify the desired number of post-trigger samples.

2-16 Available Operations

3. Specify the trigger conditions for the about trigger. – If the about trigger is an external analog trigger, use

K_SetADTrig to specify the trigger conditions for the about trigger.

– If the about trigger is an external digital trigger, use K_SetDIT rig

to specify the trigger conditions for the about trigger.

After the about-trigger acquisition is completed, the software automatically ensures that the post-trigger samples are the last samples in the buffer.

Analog Input Operations 2-17

Programming with

the Function Call Driver

This chapter contains a programming overview and language-speciﬁc information related to using the DAS-4200 Series Function Call Dri ver. It includes the following sections:

●

Programming Overview - an overview of the tasks required to write

a program using the DAS-4200 Series Function Call Driver.

●

C/C++ Programming Information - language-speciﬁc information

for programming in Microsoft C/C++ (including Visual C++) and Borland C/C++.

●

Visual Basic for Windows Programming Information -

language-speciﬁc information for programming in Microsoft Visual Basic for Windows.

3-1

Programming Overview

To write a program using the DAS-4200 Series Function Call Driver, perform the following steps:

1. Deﬁne the program's requirements. Refer to Chapter 2 for a description of the board operations supported by the Function Call Driver and the functions that you can use to deﬁne each operation.

2. Write your program. Refer to the following for additional information:

– Programming ﬂow diagrams for the preliminary tasks, on page

1-5, which illustrate the programming tasks common to all programs.

– Programming ﬂow diagrams for an analog input operation, on

page 1-6.

– Chapter 4, which contains detailed descriptions of the FCD

functions.

– The example programs in the ASO-4200 software package. The

FILES.TXT ﬁle in the installation directory lists and describes the example programs.

3. Compile and link the program. Refer to the language-specific programming information (page 3-2 to page 3-9 for C/C++ or page 3-15 for Visual Basic for Windows), or to the EXAMPLES.TXT file in the installation directory for compile and link statements and other language-specific considerations for each supported language.

C/C++ Programming Information

The following sections contain information you need to allocate and assign a memory buffer when programming in C or C++, as well as language-speciﬁc information for Microsoft C/C++ (including Visual C++) and Borland C/C++ for DOS and Windows.

3-2 Programming with the Function Call Driver

When programming in C/C++, proper typecasting may be required

Note:

to avoid C/C++ type-mismatch warnings. Make sure that linker options are set so that case-sensitivity is disabled.

Dynamically Allocating and Assigning a Memory Buffer

This section provides code fragments that describe how to allocate and assign a single, dynamically allocated memory buffer when programming in C or C++. Refer to the example programs on disk for more information.

Note:

To ensure that you can allocate a large enough buffer or buffers, it is recommended that you install the Keithley Memory Manager before you begin programming. Refer to the DAS-4200 Series User’s Guide for information on the Keithley Memory Manager.

The following code fragment illustrates how to use K_IntAlloc to allocate a buffer of size Samples for the frame deﬁned by hFrame and how to use K_SetBuf to assign the starting address of the buffer.

. . . void far *AcqBuf; //Declare pointer to buffer WORD hMem; //Declare word for memory handle . . . wDasErr = K_IntAlloc (hFrame, Samples, &AcqBuf, &hMem); wDasErr = K_SetBuf (hFrame, AcqBuf, Samples); . . .

The following code illustrates how to use K_IntFree to later free the allocated buffer, using the memory handle stored by K_IntAlloc .

. . . wDasErr = K_IntFree (hMem); . . .

C/C++ Programming Information 3-3

Accessing Data from a Dynamically Allocated Memory Buffer

You access the data stored in a dynamically allocated buffer through C/C++ pointer indirection. For example, assume that you want to display the ﬁrst 10 samples of the buffer described in the previous section (AcqBuf). The following code fragment illustrates how to access and display the data.

. . . int huge *pData; //Declare a pointer called pData . . . pData = (int huge *) AcqBuf; //Assign pData to buffer for (i = 0; i < 10; i++)

printf ("Sample #%d %X", i, *(pData+i));

. . .

Note:

Declaring pData as a huge pointer allows the program to directly access all data within the computer’s memory buffer, regardless of the buffer size.

Dimensioning a Local Array

Although it is not generally recommended for this driver, you can use a single, local array for an interrupt-mode analog input operation. A local array is useful when you are acquiring small amounts of data (less than 32,767 samples). The following code fragment illustrates how to dimension an array of 8,192 samples for the frame deﬁned by hFrame and how to use K_SetBuf to assign the starting address of the array.

. . . int Data(8192); //Dimension array of 8,192 samples . . . wDasErr = K_SetBuf (hFrame, Data, 8192); . . .

Refer to the example programs on disk for more information.

3-4 Programming with the Function Call Driver

Handling Errors

It is recommended that you always check the returned value (wDasErr in the previous examples) for possible errors. The following code fragment illustrates how to check the returned value of the K_GetDevHandle function.

. . . if ((wDASErr = K_GetDevHandle (hDrv, BoardNum, &hDev)) ! = 0)

{ printf ("Error %X during K_GetDevHandle", wDASErr); exit (1); }

. . .

The following code fragment illustrates how to use the K_GetErrMsg function to access the string corresponding to an error code.

. . . if ((wDasErr = K_SetChn (hAD, 0) ! = 0)

{ Error = K_GetErrMsg (hDev, wDasErr, &pMessage); printf ("%s", pMessage); exit (1); }

C/C++ Programming Information 3-5

Programming in Microsoft C/C++ (for DOS)

To program in Microsoft C/C++ (for DOS), you need the following ﬁles; these ﬁles are provided in the ASO-4200 software package.

File Description

DAS4200.LIB Linkable driver DASRFACE.LIB Linkable driver DASDECL.H Include ﬁle when compiling in C DASDECL.HPP Include ﬁle when compiling in C++ USE4200.OBJ Linkable object

To create an executable ﬁle in Microsoft C/C++ (for DOS), use the following compile and link statements. Note that ﬁlename indicates the name of your program.

Type of Compile Compile and Link Statements

C CL /c ﬁlename .c

LINK ﬁlename +use4200.obj,,,das4200+dasrface;

C++ CL /c ﬁlename .cpp

LINK ﬁlename +use4200.obj,,,das4200+dasrface;

Notes

These statements assume a large memory model; in DOS, only the large

memory model is acceptable.

3-6 Programming with the Function Call Driver

Programming in Microsoft C/C++ (for Windows)

The ﬁles you need to program in Microsoft C/C++ (for Windows), including Microsoft Visual C++, depend on whether you are writing 16-bit or 32-bit programs. The following ﬁles are provided either in the ASO-4200 software package or on the ASO-Win95/32-Bit disk, which is shipped with the ASO-4200 software package:

Program File Description

16 bits DASSHELL.DLL Dynamic Link Library of Shell functions

DASSUPRT.DLL Dynamic Link Library of support functions DAS4200.DLL Dynamic Link Library of board-speciﬁc functions DASDECL.H Include ﬁle of Shell function deﬁnitions (used when

compiling in C or C++)

DASIMP.LIB Import library of Shell functions

32-bits DASSHL32.DLL Dynamic Link Library of Shell functions

DASSUPRT.DLL Dynamic Link Library of support functions DASSHL16.DLL Dynamic Link Library of support functions DAS4200.DLL Dynamic Link Library of board-speciﬁc functions DASDECL.H Include ﬁle of Shell function deﬁnitions (used when

compiling in C or C++)

DASSHL32.LIB Import library of Shell functions

To create an executable ﬁle in the Microsoft C/C++ for Windows environment, perform the following steps. Refer to the documentation supplied with your compiler for information.

1. Create a project ﬁle.

2. Add all necessary ﬁles to the project make ﬁle. Make sure that you

include ﬁlename .c (or ﬁlename .cpp), ﬁlename .rc, ﬁlename .def, DASIMP.LIB (or DASSHL32.LIB), and D4200IMP.LIB (16-bit programs only), where ﬁlename indicates the name of your program.

3. Create a stand-alone executable ﬁle (.EXE) that you can run from

within Windo ws.

C/C++ Programming Information 3-7

Programming in Borland C/C++ (for DOS)

To program in Borland C/C++ (for DOS), you need the following ﬁles; these ﬁles are provided in the ASO-4200 software package.

File Description

DAS4200.LIB Linkable driver DASRFACE.LIB Linkable driver DASDECL.H Include ﬁle when compiling in C DASDECL.HPP Include ﬁle when compiling in C++ USE4200.OBJ Linkable object

To create an executable ﬁle in Borland C/C++ (for DOS), use the following compile and link statements. Note that ﬁlename indicates the name of your program.

Type of Compile Compile and Link Statements

C BCC ﬁlename .c use4200.obj das4200.lib dasrface.lib C++ BCC ﬁlename .cpp use4200.obj das4200.lib dasrface.lib

Notes

These statements assume a large memory model; in DOS, only the large memory

model is acceptable.

3-8 Programming with the Function Call Driver

Programming in Borland C/C++ (for Windows)

The ﬁles you need to program in Borland C/C++ (for Windows) depend on whether you are writing 16-bit or 32-bit programs. The following ﬁles are provided either in the ASO-4200 software package or on the ASO-Win95/32-Bit disk, which is shipped with the ASO-4200 software package:

Program File Description

16 bits DASSHELL.DLL Dynamic Link Library of Shell functions

DASSUPRT.DLL Dynamic Link Library of support functions DAS4200.DLL Dynamic Link Library of board-speciﬁc functions DASDECL.H Include ﬁle of Shell function deﬁnitions (used when

compiling in C or C++)

DASIMP.LIB Import library of Shell functions

32-bits DASSHL32.DLL Dynamic Link Library of Shell functions

compiling in C or C++)

DASSHL32.LIB Import library of Shell functions

To create an executable ﬁle in the Borland C/C++ (for Windows) environment, perform the following steps:

1. Create a project ﬁle.

2. Add all necessary ﬁles to the project make ﬁle. Make sure that you

include ﬁlename .c (or ﬁlename .cpp), ﬁlename .rc, ﬁlename .def, DASIMP.LIB (or DASSHL32.LIB), and D4200IMP.LIB (16-bit programs only), where ﬁlename indicates the name of your program.

C/C++ Programming Information 3-9

3. Make sure that you turn OFF the following options for the project:

– Case sensitive link – Case sensitive exports and imports – Ignore default libraries

4. Create a stand-alone executable ﬁle (.EXE) that you can run from

within Windo ws.

Microsoft Visual Basic for Windows Programming Information

The following sections contain information you need to dimension an array or dynamically allocate a memory buffer when programming in Microsoft Visual Basic for Windows, as well as language-speciﬁc information for Microsoft Visual Basic for Windows.

Dynamically Allocating and Assigning a Memory Buffer

This section provides code fragments that describe how to allocate and assign a single, dynamically allocated memory buffer when programming in Microsoft Visual Basic for Windows. Refer to the example programs on disk for more information.

Note:

recommended that you use the Keithley Memory Manager before you begin programming. Refer to your DAS-4200 Series User’s Guide for more information on the Keithley Memory Manager.

To ensure that you can allocate a large enough buffer, it is

3-10 Programming with the Function Call Driver

You can use a single, dynamically allocated memory buffer for an interrupt-mode analog input operation. The following code fragment illustrates how to use K_IntAlloc to allocate a buffer of size Samples for the frame deﬁned by hFrame and how to use K_SetBuf to assign the starting address of the buffer.

. . . Global AcqBuf As Long ’ Declare pointer to buffer Global hMem As Integer ’ Declare integer for memory handle . . . wDasErr = K_IntAlloc (hFrame, Samples, AcqBuf, hMem) wDasErr = K_SetBuf (hFrame, AcqBuf, Samples) . . .

The following code illustrates how to use K_IntFree to later free the allocated buffer, using the memory handle stored by K_IntAlloc .

. . . wDasErr = K_IntFree (hMem) . . .

Accessing Data from a Dynamically Allocated Memory Buffer

In Microsoft Visual Basic for Windo ws, you cannot directly access analog input samples stored in a dynamically allocated memory buffer. You must use K_MoveBufToArray to move a subset (up to 32,766 samples) of the data into a local array as required.

When Windows is running, the CPU operates in 16-bit protected mode. Memory is addressed using a 32-bit selector:offset pair. The selector is the CPU’s handle to a 64K byte memory page; it is a code whose value is signiﬁcant only to the CPU. No mathematical relationship exists between a selector and the memory location it is associated with. In general, even consecutively allocated selectors have no relationship to each other.

When a memory buffer of more than 64K bytes (32K values) is used, multiple selectors are required. Under Windows, K_IntAlloc uses a “tiled” method to allocate memory whereby a mathematical relationship does exist among the selectors. Speciﬁcally , when you allocate a b uf fer of more than 64K bytes, each selector that is allocated has an arithmetic value that is eight greater than the previous one. The format of the address is a 32-bit value whose high word is the 16-bit selector value and low word is the 16-bit offset value. When the offset reaches 64K bytes, the

Microsoft Visual Basic for Windows Programming Information 3-11

next consecutive memory address location can be accessed by adding eight to the selector and resetting the offset to zero; to do this, add &h80000 to the buffer starting address.

Table 3-1 illustrates the mapping of consecutive memory locations in protected-mode “tiled” memory, where xxxxxxxx indicates the address calculated by the CPU memory mapping mechanism.

Table 3-1. Protected-Mode Memory Architecture

Selector:Offset 32-Bit Linear

Address

. . . . : . . . . . . . . .

32E6:FFFE 32E6:FFFF 32EE:0000 32EE:0001

. . . . : . . . . . . . . .

The following code fragment illustrates moving 1,000 values from a memory buffer (AcqBuf) allocated with 50,000 values to the program’s local array (Array), starting at the sample at buffer index 40,000. First, start with the buffer address passed in K_SetBuf . Then, determine how deep (in 64K byte pages) into the buffer the desired starting sample is located and add &h80000 to the buffer address for each 64K byte page. Finally, add any additional offset after the 64K byte pages to the buffer address.

Dim AcqBuf As Long Dim NumSamps As Long

Dim Array(1000) As Integer

xxxxxxxx xxxxxxxx + 1 xxxxxxxx + 2 xxxxxxxx + 3

NumSamps = 50000 wDasErr = K_IntAlloc (hFrame, NumSamps, AcqBuf, hMem) . . ’Acquisition routine .

3-12 Programming with the Function Call Driver

DesiredSamp = 40000 DesiredByte = DesiredSamp * 2 ’Number of bytes into buffer AddSelector = DesiredByte / &h10000 ’Number of 64K pages into buffer RemainingOffset = DesiredByte Mod &h10000 ’Additional offset

DesiredBuffLoc = AcqBuf + (AddSelector * &h80000) + RemainingOffset

wDasErr = K_MoveBufToArray (Array(0), DesiredBuffLoc, 1000)

To move more than 32,767 values from the memory buffer to the program’s local array, the program must call K_MoveBufToArray more than once. For example, assume that pBuf is a pointer to a dynamically allocated buffer that contains 65,536 v alues. The follo wing code fragment illustrates how to move 65,536 values from the dynamically allocated buffer to a local array within the program:

... Dim Data [3, 16384] As Integer ... wDasErr = K_MoveBufToArray (Data(0,0), pBuf, 16384)

’Same selector, add 32,768 bytes to offset: add &h8000 wDasErr = K_MoveBufToArray (Data(1,0), pBuf + &h8000, 16384) ’Add 8 to selector, offset = 0: add &h80000 wDasErr = K_MoveBufToArray (Data(2,0), pBuf + &h80000, 16384) ’Add 8 to selector, add 32,768 bytes to offset: add &h88000 wDasErr = K_MoveBufToArray (Data(3,0), pBuf + &h88000, 16384)

Dimensioning and Assigning a Local Array

If you request fewer than 32,767 samples for an interrupt-mode analog input operation, you can use a single, local array. The following code fragment illustrates how to dimension an array of 8192 samples for the frame deﬁned by hFrame and how to use K_SetBufI to assign the starting address of the array.

. . . Global Data(8191) As Integer ’Allocate array . . . wDasErr = K_SetBufI (hFrame, Data(0), 8192) . . .

Refer to the example programs on disk for more information.

Microsoft Visual Basic for Windows Programming Information 3-13

Handling Errors

. . . wDASErr = K_GetDevHandle (hDrv, BoardNum, hDev) If (wDASErr <> 0) Then

MsgBox "K_GetDevHandle Error: " + Hex$ (wDASErr),

MB_ICONSTOP, "DAS-4200 SERIES ERROR"

End End If . . .

3-14 Programming with the Function Call Driver

Programming in Microsoft Visual Basic for Windows

The ﬁles you need to program in Microsoft Visual Basic for Windows depend on whether you are writing a 16-bit or 32-bit program. The following ﬁles are provided either in the ASO-4200 software package or on the ASO-Win95/32-Bit disk, which is shipped with the ASO-4200 software package.

Program File Description

16 bits DASSHELL.DLL Dynamic Link Library

DASSUPRT.DLL Dynamic Link Library DAS4200.DLL Dynamic Link Library DASDECL.BAS Include ﬁle DAS4200.BAS Include ﬁle of board-speciﬁc function deﬁnitions

32 bits DASSHL32.DLL Dynamic Link Library of Shell functions

DASSUPRT.DLL Dynamic Link Library of support functions DASSHL16.DLL Dynamic Link Library of support functions DASDEC32.BAS Include ﬁle of Shell function deﬁnitions

To create an executable ﬁle from the Microsoft Visual Basic for Windows environment, perform the following steps:

1. Start Visual Basic for Windows, and open your project.

2. Add the appropriate include ﬁle(s) to your project: – 16-bit programs - DASDECL.BAS and DAS4200.BAS ﬁles – 32-bit programs - DASDEC32.BAS ﬁle

3. Create an executable (EXE) ﬁle.

Microsoft Visual Basic for Windows Programming Information 3-15

Function Reference

The FCD functions are organized into the following groups:

Initialization functions

●

Operation functions

●

Frame management functions Memory management functions

●

Buffer address functions

●

Channel and gain functions

●

Clock functions Trigger functions

●

Miscellaneous functions

●

The particular functions associated with each function group are presented in Table 4-1. The remainder of the chapter presents detailed descriptions of all the FCD functions, arranged in alphabetical order.

. 4-1

Table 4-1. Functions

Function Type Function Name Page Number

Initialization K_OpenDriver page 4-31

K_CloseDriver page 4-6 K_GetDevHandle page 4-15 K_FreeDevHandle page 4-9 K_DASDevInit page 4-8

Operation K_IntStart page 4-24

K_IntStatus page 4-25 K_IntStop page 4-28

Frame Management K_GetADFrame page 4-11

K_FreeFrame page 4-10 K_ClearFrame page 4-5

Memory Management K_IntAlloc page 4-21

K_IntFree page 4-23 K_MoveBufToArray page 4-30

Buffer Address K_SetBuf page 4-37

K_SetBufI page 4-39

Channel and Gain K_SetChn page 4-41

K_SetG page 4-47

Clock K_SetClk page 4-42

K_SetClkRate page 4-43 K_GetClkRate page 4-13

Trigger K_SetTrig page 4-49

K_SetADTrig page 4-35 K_SetDITrig page 4-45 K_SetAboutTrig page 4-33 K_ClrAboutTrig page 4-7

4-2 Function Reference

Table 4-1. Functions (cont.)

Function Type Function Name Page Number

Miscellaneous K_GetErrMsg page 4-17

K_GetVer page 4-19 K_GetShellVer page 4-18

Keep the following conventions in mind throughout this chapter:

The data types DWORD, WORD, and BYTE are deﬁned in the

●

language-speciﬁc include ﬁles.

●

Variable names are shown in italics.

●

The return value for all DAS-4200 Series FCD functions is the error/status code. A value of 0 indicates that the function executed successfully . A non-zero value indicates that an error occurred. Refer to Appendix A for more information.

The description shows the prototype for the function.

●

In the Usage section, the variables are not deﬁned. It is assumed that the variables are deﬁned as shown in the prototype.

. 4-3

The name of each function argument in the Prototype and Usage sections includes a prefix that indicates the associated data type. These prefixes are described in Table 4-2.

Table 4-2. Data Type Preﬁxes

Preﬁx Data T ype Comments

sz Pointer to string terminated by

zero

h Handle to device, frame, and

memory block

ph Pointer to a handle-type variable This data type is used when calling the FCD functions

p Pointer to a variable This data type is used for pointers to all types of

n Number value This data type is used when passing a number,

w 16-bit word This data type is typically used when passing an

a Array This data type is typically used in conjunction with

This data type is typically used for variables that specify the driver's conﬁguration ﬁle name.

This data type is used for handle-type variables. You declare handle-type variables in your program as long or DWORD, depending on the language you are using. The actual variable is passed to the driver by value.

to get a driver handle, frame handle, device handle, or memory handle. The actual variable is passed to the driver by reference.

variables, except handles (h). It is typically used when passing a parameter of any type to the driver by reference.

typically a byte, to the driver by value.

unsigned integer to the driver by value.

other preﬁxes listed here; for example, anVar denotes an array of numbers.

f Float This data type denotes a single-precision ﬂoating-point

number.

d Double This data type denotes a double-precision

ﬂoating-point number.

dw 32-bit double word This data type is typically used when passing an

unsigned long to the driver by value.

4-4 Function Reference

K_ClearFrame

Purpose

Prototype C/C++

Sets the elements of a frame to their default values.

DASErr far pascal K_ClearFrame (DWORD hFrame );

Visual Basic for Windows

Declare Function K_ClearFrame Lib "DASSHELL.DLL" (ByVal hFrame As Long) As Integer

Parameters

Return Value

Remarks

hFrame

Error/status code. Refer to Appendix A.

This function sets the elements of the frame speciﬁed by hFrame to their default values.

Refer to T able 2-1 on page 2-6 for the def ault v alues of the elements of an A/D frame.

See Also

Usage C/C++

K_GetADFrame

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_ClearFrame (hAD);

Handle to the frame that deﬁnes the operation.

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_ClearFrame (hAD)

4-5

K_CloseDriver

Purpose

Prototype C/C++

Closes a previously initialized Keithley DAS Function Call Driver.

DASErr far pascal K_CloseDriver (DWORD hDrv );

Visual Basic for Windows

Declare Function K_CloseDriver Lib "DASSHELL.DLL" (ByVal hDrv As Long) As Integer

Parameters

Return Value

Remarks

hDrv

Error/status code. Refer to Appendix A.

This function frees the driver handle speciﬁed by hDrv and closes the associated use of the Function Call Driver. This function also frees all device handles and frame handles associated with hDrv .

If hDrv is the last driver handle speciﬁed for the Function Call Dri v er, the driver is shut down (for all languages) and unloaded (for Windows-based languages only).

See Also

K_FreeDevHandle

Driver handle you want to free.

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_CloseDriver (hDrv);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_CloseDriver (hDrv)

4-6 Function Reference

K_ClrAboutTrig

Purpose

Prototype C/C++

Disables the about trigger for an analog input operation.

DASErr far pascal K_ClrAboutTrig (DWORD hFrame );

Visual Basic for Windows

Declare Function K_ClrAboutTrig Lib "DASSHELL.DLL" (ByVal hFrame As Long) As Integer

Parameters

Return Value

Remarks

hFrame

Error/status code. Refer to Appendix A.

This function disables the about trigger for the operation deﬁned by

hFrame .

If you disable the about trigger, the trigger source speciﬁed in K_SetTrig is always the start trigger.

K_GetADFrame and K_ClearFrame also disable the about trigger.

See Also

K_ClearFrame, K_GetADFrame, K_SetAboutTrig

Handle to the frame that deﬁnes the operation.

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_ClrAboutTrig (hAD);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_ClrAboutTrig (hAD)

4-7

K_DASDevInit

Purpose

Prototype C/C++

Reinitializes a board.

DASErr far pascal K_DASDevInit (DWORD hDev );

Visual Basic for Windows

Declare Function K_DASDevInit Lib "DASSHELL.DLL" (ByVal hDev As Long) As Integer

Parameters

Return Value

Remarks

hDev

Error/status code. Refer to Appendix A.

Use K_GetDevHandle the ﬁrst time you initialize a board only . Once you have a device handle, use this function to reinitialize the board.

See Also

Usage C/C++

K_GetDevHandle

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_DASDevInit (hDev);

Handle associated with the board.

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_DASDevInit (hDev)

4-8 Function Reference

K_FreeDevHandle

Purpose

Prototype C/C++

Frees a previously speciﬁed device handle.

DASErr far pascal K_FreeDevHandle (DWORD hDev );

Visual Basic for Windows

Declare Function K_FreeDevHandle Lib "DASSHELL.DLL" (ByVal hDev As Long) As Integer

Parameters

Return Value

Remarks

hDev

Error/status code. Refer to Appendix A.

This function frees the device handle speciﬁed by hDev as well as all frame handles associated with hDev.

See Also

Usage C/C++

K_GetDevHandle

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_FreeDevHandle (hDev);

Device handle you want to free.

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_FreeDevHandle (hDev)

4-9

K_FreeFrame

Purpose

Prototype C/C++

Frees a frame.

DASErr far pascal K_FreeFrame (DWORD hFrame);

Visual Basic for Windows

Declare Function K_FreeFrame Lib "DASSHELL.DLL" (ByVal hFrame As Long) As Integer

Parameters

Return Value

Remarks

hFr ame Handle to frame you want to free.

Error/status code. Refer to Appendix A.

This function frees the frame speciﬁed by hFrame, making the frame available for another operation.

See Also

Usage C/C++

K_GetADFrame

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_FreeFrame (hAD);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_FreeFrame (hAD)

4-10 Function Reference

K_GetADFrame

Purpose

Prototype C/C++

Accesses an A/D frame for an analog input operation.

DASErr far pascal K_GetADFrame (DWORD hDev, DWORD far * phFrame);

Visual Basic for Windows

Declare Function K_GetADFrame Lib "DASSHELL.DLL" (ByVal hDev As Long, phF rame As Long) As Integer

Parameters

hDev Handle associated with the board. phFrame Handle to the frame that deﬁnes the operation.

Return Value

Remarks

Error/status code. Refer to Appendix A.

This function speciﬁes that you want to perform an analog input operation on the board speciﬁed by hDev , and accesses an a v ailable A/D frame with the handle phFrame. The frame is initialized to its default settings; the default settings are given in Table 2-1 on page 2-6.

The value stored in phFrame is intended to be used exclusively as an argument to functions that require a frame handle. Your program should not modify the value stored in phFrame.

See Also

Usage C/C++

K_ClearFrame, K_FreeFrame

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... DWORD hAD; ... wDasErr = K_GetADFrame (hDev, &hAD);

4-11

K_GetADFrame (cont.)

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global hAD As Long ... wDasErr = K_GetADFrame (hDev, hAD)

4-12 Function Reference

K_GetClkRate

Purpose

Prototype C/C++

Gets the clock divider for the internal pacer clock.

DASErr far pascal K_GetClkRate (DWORD hFrame, DWORD far *pRate);

Visual Basic for Windows

Declare Function K_GetClkRate Lib "DASSHELL.DLL" (ByVal hFrame As Long, pRate As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. pRate Clock divider.

The following table shows the clock divider values stored and the corresponding conversion rates and sample periods for the internal pacer clock

Value stored: See the table below.

Clock Divider

32 100 Msamples/s 10 ns

Conversion Rate

Sample Period

Return Value

64 50 Msamples/s 20 ns 128 25 Msamples/s 40 ns 256 12.5 Msamples/s 80 ns 512 6.25 Msamples/s 160 ns 1024 3.13 Msamples/s 320 ns 2048 1.56 Msamples/s 640 ns 4096 0.78 Msamples/s 1280 ns

Error/status code. Refer to Appendix A.

4-13

K_GetClkRate (cont.)

Remarks

For the operation deﬁned by hFr ame, this function stores the clock divider for the internal pacer clock in pRate.

The pRate variable contains the value of the Pacer Clock Rate element.

See Also

Usage C/C++

K_SetClkRate

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... DWORD dwRate; ... wDasErr = K_GetClkRate (hAD, &dwRate);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global dwRate As Long ... wDasErr = K_GetClkRate (hAD, dwRate)

4-14 Function Reference

K_GetDevHandle

Purpose

Prototype C/C++

Initializes any Keithley DAS board.

DASErr far pascal K_GetDevHandle (DWORD hDrv, WORD nBoardNum, DWORD far * phDev);

Visual Basic for Windows

Declare Function K_GetDevHandle Lib "DASSHELL.DLL" (ByVal hDrv As Long, ByVal nBoardNum As Integer, phDev As Long) As Integer

Parameters

hDrv Driver handle of the associated Function Call

nBoardNum Board number.

phDev Handle associated with the board.

Return Value

Remarks

Error/status code. Refer to Appendix A.

This function initializes the board associated with hDrv and speciﬁed by nBoardNum, and stores the device handle of the speciﬁed board in phDev.

Driver.

Valid values: 0 to 1

See Also

The value stored in phDev is intended to be used exclusively as an argument to functions that require a device handle. Your program should not modify the value stored in phDev.

Use this function the ﬁrst time you initialize a board only . Once you have a device handle (phDev), use the

K_DASDevInit function to reinitialize

the board.

K_DASDevInit, K_FreeDevHandle

4-15

K_GetDevHandle (cont.)

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... DWORD phDev; ... wDasErr = K_GetDevHandle (hDrv, 0, &phDev);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global phDev As Long ... wDasErr = K_GetDevHandle (hDrv, 0, phDev)

4-16 Function Reference

K_GetErrMsg

Purpose

Prototype C/C++

Gets the address of an error message string.

DASErr far pascal K_GetErrMsg (DWORD hDev, short nDASErr, char far * far * pErrMsg);

Visual Basic for Windows

Not supported

Parameters

hDev Handle associated with the board. nDASErr Error message number. pErrMsg Address of error message string.

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the board speciﬁed by hDev, this function stores the address of the string corresponding to error message number nDASErr in pErrMsg.

Refer to page 2-3 for more information about error handling. Refer to Appendix A for a list of error codes and their meanings.

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... char far *pErrMsg; ... wDasErr = K_GetErrMsg (hDev, wDASErr, &pErrMsg);

4-17

K_GetShellVer

Purpose

Prototype C/C++

Gets the current DAS shell version.

DASErr far pascal K_GetShellVer (WORD far *pVersion);

Visual Basic for Windows

Declare Function K_GetShellVer Lib "DASSHELL.DLL" (pVersion As Integer) As Integer

Parameters

Return Value

Remarks

pV er sion A word value containing the major and minor

Error/status code. Refer to Appendix A.

This function stores the current DAS Shell version in pVersion. To obtain the major version number of the DAS shell, divide pVersion by

256. To obtain the minor version number of the DAS shell, perform a

Boolean AND operation with pVersion and 255 (0FFh).

Usage

version numbers of the DAS shell.

C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... WORD wShellVer; wDasErr = K_GetShellVer (&wShellVer); printf ("Shell Ver %d.%d", wShellVer >> 8, wShellVer & 0xff);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global wShellVer As Integer ... wDasErr = K_GetShellVer (wShellVer) ShellVer$ = LTRIM$(STR$(INT(wShellVer / 256))) + "." + LTRIM$(STR$(wShellVer AND &HFF)) Msgbox "Shell Version: " + ShellVer$

4-18 Function Reference

K_GetVer

Purpose

Prototype C/C++

Gets revision numbers.

DASErr far pascal K_GetVer (DWORD hDev, short far * pSpecVer, short far * pDrvVer);

Visual Basic for Windows

Declare Function K_GetVer Lib "DASSHELL.DLL" (ByVal hDev As Long, pSpecV er As Integer, pDrvV er As Integer) As Integer

Parameters

hDev Handle associated with the board. pSpecVer Revision number of the Keithley DAS Driver

pDrvVer Driver version number.

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the board speciﬁed by hDev, this function stores the revision number of the DAS-4200 Series Function Call Dri v er in pDrvVer and the revision number of the driver speciﬁcation in pSpecVer.

Speciﬁcation to which the driver conforms.

The values stored in pSpecVer and pDrvV er are two-byte (16-bit) inte gers; the high byte of each contains the major revision lev el and the lo w byte of each contains the minor revision level. For example, if the driver version number is 2.10, the major revision level is 2 and the minor revision level is 10; therefore, the high byte of pDrvVer contains the value of 2 (512) and the low byte of pDrvVer contains the value of 10; the value of both bytes is 522.

To obtain the major version number of the Function Call Driver, divide pDrvVer by 256; to obtain the minor version number of the Function Call Driver, perform a Boolean AND operation with pDrvVer and 255 (0FFh).

To obtain the major version number of the driver speciﬁcation, divide pSpecVer by 256; to obtain the minor version number of the driver speciﬁcation, perform a Boolean AND operation with pSpecVer and 255 (0FFh).

4-19

K_GetVer (cont.)

Usage

C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... short nSpecVer, nDrvVer; ... wDasErr = K_GetVer (hDev, &nSpecVer, &nDrvVer); printf ("Driver Ver %d.%d", nDrvVer >> 8, nDrvVer & 0xff);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global nSpecVer As Integer Global nDrvVer As Integer ... wDasErr = K_GetVer (hDev, nSpecVer, nDrvVer) DrvVer$ = LTRIM$(STR$(INT(nDrvVer / 256))) + "." + LTRIM$(STR$(nDrvVer AND &HFF)) Msgbox "Driver Version: " + DrvVer$

4-20 Function Reference

K_IntAlloc

Purpose

Prototype C/C++

Allocates a buffer for an analog input operation.

DASErr far pascal K_IntAlloc (DWORD hFrame, DWORD dwSamples, void far * far *pBuf, WORD far *phMem);

Visual Basic for Windows

Declare Function K_IntAlloc Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal dwSamples As Long, pBuf As Long, phMem As Integer) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. dwSamples Number of samples.

pBuf Starting address of the allocated buffer. phMem Handle associated with the allocated buffer.

Return Value

Error/status code. Refer to Appendix A.

Valid values:

1 to 131072 for the DAS-4201/128K board 1 to 524288 for the DAS-4201/512K board

Remarks

See Also

For the operation deﬁned by hFrame, this function allocates a buffer of the size speciﬁed by dwSamples, and stores the starting address of the buffer in pBuf and the handle of the buffer in phMem.

The data in the allocated buffer is stored as counts. Refer to Appendix B for information on converting a count value to voltage.

The value stored in phMem is intended to be used exclusively as an argument to functions that require a memory handle. Your program should not modify the value stored in phMem.

K_IntFree, K_SetBuf

4-21

K_IntAlloc (cont.)

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... void far *pBuf; // Pointer to allocated buffer WORD phMem; // Memory Handle to buffer ... wDasErr = K_IntAlloc (hAD, 131072, &pBuf, &phMem);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global pBuf As Long Global phMem As Integer ... wDasErr = K_IntAlloc (hAD, 131072, pBuf, phMem)

4-22 Function Reference

K_IntFree

Purpose

Prototype C/C++

Frees a buffer allocated for an analog input operation.

DASErr far pascal K_IntFree (WORD phMem);

Visual Basic for Windows

Declare Function K_IntFree Lib "DASSHELL.DLL" (ByVal phMem As Integer) As Integer

Parameters

Return Value

Remarks

phMem Handle to buffer.

Error/status code. Refer to Appendix A.

This function frees the buffer speciﬁed by phMem; the buffer was previously allocated dynamically using K_IntAlloc.

See Also

Usage C/C++

K_IntAlloc

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_IntFree (phMem);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_IntFree (phMem)

4-23

K_IntStart

Purpose

Prototype C/C++

Starts an analog input operation.

DASErr far pascal K_IntStart (DWORD hFrame);

Visual Basic for Windows

Declare Function K_IntStart Lib "DASSHELL.DLL" (ByVal hFrame As Long) As Integer

Parameters

Return Value

Remarks

hFr ame Handle to the frame that deﬁnes the operation.

Error/status code. Refer to Appendix A.

This function starts the operation deﬁned by hFrame. Refer to page 1-4 for a summary of the programming tasks associated with analog input operations.

See Also

Usage C/C++

K_IntStatus, K_IntStop

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_IntStart (hAD);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_IntStart (hAD)

4-24 Function Reference

K_IntStatus

Purpose

Gets the status of an analog input operation.

Prototype C/C++

DASErr far pascal K_IntStatus (DWORD hFrame, short far *pStatus, DWORD far *pCount);

Visual Basic for Windows

Declare Function K_IntStatus Lib "DASSHELL.DLL" (ByVal hFrame As Long, pStatus As Integer, pCount As Long) As Integer

Parameters

hFrame Handle to the frame that deﬁnes the operation. pStatus Status of operation; see Remarks below for

pCount Current number of samples transferred into the

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function stores the status in

pStatus and the current number of samples transferred into the buffer in pCount.

value stored.

buffer.

Bit

The value stored in pStatus depends on the settings in the Status word, as shown below:

About-trigger 00 = Disabled 01 = Armed 11 = Done

0 = Interrupt operation inactive 1 = Interrupt operation active

0 = Buffer not ﬁlled 1 = Buffer ﬁlled

4-25

K_IntStatus (cont.)

The bits are described as follows:

● Bit 0: This bit indicates whether an analog input operation is in

progress.

● Bits 1 to 3: Not used.

● Bit 4: This bit is set when the buffer that is assigned to the active

operation has been ﬁlled with data.

● Bits 6 and 7: These bits indicate the state of the about trigger.

● Bits 8 to 15: Not used.

Figure 4-1. Status Word Settings

See Also

K_IntStart, K_IntStop

4-26 Function Reference

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... WORD wStatus; DWORD dwCount; ... wDasErr = K_IntStatus (hAD, &wStatus, &dwCount);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global wStatus As Integer Global dwCount As Long ... wDasErr = K_IntStatus (hAD, wStatus, dwCount)

K_IntStatus (cont.)

4-27

K_IntStop

Purpose

Prototype C/C++

Stops an analog input operation.

DASErr far pascal K_IntStop (DWORD hFrame, short far *pStatus, DWORD far *pCount);

Visual Basic for Windows

Declare Function K_IntStop Lib "DASSHELL.DLL" (ByVal hFrame As Long, pStatus As Integer, pCount As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. pStatus Status of operation. pCount Current number of samples transferred into the

Return Value

Remarks

Error/status code. Refer to Appendix A.

This function stops the board from acquiring data, disables the operation, and returns the status of the operation at the point when your program called this function. No data is transferred into the buffer in computer memory.

buffer.

Refer to page 4-25 for more information on the status word returned. If you are using an external start or about trigger, call this function if the

trigger event does not occur.

See Also

Usage C/C++

4-28 Function Reference

K_IntStart, K_IntStatus

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... WORD wStatus; DWORD dwCount; ... wDasErr = K_IntStop (hAD, &wStatus, &dwCount);

K_IntStop (cont.)

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global wStatus As Integer Global dwCount As Long ... wDasErr = K_IntStop (hAD, wStatus, dwCount)

4-29

K_MoveBufToArray

Purpose

Transfers data from a buffer allocated through K_IntAlloc to a locally dimensioned array.

Prototype C/C++

Not supported

Visual Basic for Windows

Declare Function K_MoveBufToArray Lib "DASSHELL.DLL" Alias "K_MoveDataBuf" (pDest As Integer, ByVal pSource As Long, ByV al nCount As Integer) As Integer

Parameters

pDest Address of destination array. pSource Address of source buffer. nCount Number of samples to transfer.

Return Value

Remarks

Error/status code. Refer to Appendix A.

This function transfers the number of samples speciﬁed by nCount from the buffer at address pSource to the array at address pDest.

Value values: 1 to 32767

In Visual Basic for Windows, the buffer allocated through K_IntAlloc is not accessible to your program; you must use K_MoveBufToArray to move the data from the allocated buffer to the program’s local array.

See Also

Usage Visual Basic for Windows

4-30 Function Reference

K_IntAlloc

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Dim ADArray(2000) As Integer ... wDasErr = K_IntAlloc (hAD, 131072, pBuf, hMem) ... wDasErr = K_MoveBufToArray (ADArray(0), pBuf, 1000)

K_OpenDriver

Purpose

Prototype C/C++

Initializes any Keithley DAS Function Call Driver.

DASErr far pascal K_OpenDriver (char far * szDrvName, char far * szCfgName, DWORD far * phDrv);

Visual Basic for Windows

Declare Function K_OpenDriver Lib "DASSHELL.DLL" (ByVal szDrvName As String, ByVal szCfgName As String, phDrv As Long) As Integer

Parameters

szDrvName Board name.

szCfgName Driver conﬁguration ﬁle.

phDrv Handle associated with the driver.

Return Value

Error/status code. Refer to Appendix A.

Valid value: "DAS4200" (for DAS-4200

Series boards)

Valid values: The name of a conﬁguration ﬁle;

0 if driver has already been opened

Remarks

This function initializes the DAS-4200 Series Function Call Driver according to the information in the configuration file specified by szCfgName, and stores the driver handle in phDrv.

You can use this function to initialize the Function Call Driver associated with any Keithley MetraByte DAS board. For DAS-4200 Series boards, the string stored in szDrvName must be DAS4200. Refer to other Function Call Driver user’s guides for the appropriate string to store in szDrvName for other Keithley MetraByte DAS boards.

The value stored in phDrv is intended to be used exclusively as an argument to functions that require a driver handle. Your program should not modify the value stored in phDrv.

You create a conﬁguration ﬁle using the CFG4200.EXE utility. Refer to your DAS-4200 Series User’s Guide for more information.

4-31

K_OpenDriver (cont.)

If szCfgName = 0, K_OpenDriver checks whether the driver has already been opened and linked to a conﬁguration ﬁle and if it has, uses the current conﬁguration; this is useful in the Windows environment.

Usage

C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++

... DWORD phDrv; ... wDasErr = K_OpenDriver ("DAS4200", "DAS4200.CFG", &phDrv);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... DIM phDrv As Long ... wDasErr = K_OpenDriver("DAS4200", "DAS4200.CFG", phDrv)

4-32 Function Reference

K_SetAboutTrig

Purpose

Enables the about trigger and speciﬁes the number of post-trigger samples.

Prototype C/C++

DASErr far pascal K_SetAboutTrig (DWORD hFrame, DWORD dwSamples);

Visual Basic for Windows

Declare Function K_SetAboutTrig Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal dwSamples As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. dwSamples Number of post-trigger samples.

Return Value

Remarks

Error/status code. Refer to Appendix A.

This function enables the about trigger and speciﬁes the number of post-trigger samples in dwSamples.

Valid values:

1 to 131072 for the DAS-4201/128K board 1 to 524288 for the DAS-4201/512K board

Note that you cannot use an about trigger with an external start trigger. If you enable the about trigger and specify an external trigger source in K_SetTrig, the software assumes that the external trigger is the about trigger. For pre-trigger and about-trigger acquisition, the start trigger is always an internal trigger.

See Also

Usage C/C++

K_ClrAboutTrig

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_SetAboutTrig (hAD, 100);

4-33

K_SetAboutTrig (cont.)

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

wDasErr = K_SetAboutTrig (hAD, 100)

4-34 Function Reference

K_SetADTrig

Purpose

Prototype C/C++

Sets up an external analog start or about trigger.

DASErr far pascal K_SetADTrig (DWORD hFrame, short nOpt, short nChan, DWORD dwLevel);

Visual Basic for Windows

Declare Function K_SetADTrig Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal nOpt As Integer, ByV al nChan As Integer, ByVal dwLevel As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. nOpt Analog trigger polarity and sensitivity.

nChan Analog input channel.

dwLevel Level at which the trigger ev ent occurs, speciﬁed

Valid values: 0 for Positive edge

1 for Positive level 2 for Negative edge 3 for Negative level

Valid values: 0, 1

in counts. Valid values:

−128 to 127

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function speciﬁes the channel used for an analog trigger in nChan, the level used for the analog trigger in dwLevel, and the trigger polarity and trigger sensitivity in nOpt.

The analog input channel you specify in nChan must be the same as the analog input channel that is sampled; otherwise, the driver returns an error.

You specify the value for dwLevel in counts. Refer to Appendix B for information on converting the actual voltage to a count value.

4-35

K_SetADTrig (cont.)

The values you specify set the following elements in the frame identiﬁed by hFrame:

● nOpt sets the value of the Trigger Polarity and Trigger Sensitivity

elements.

● nChan sets the value of the Trigger Channel element.

● dwLevel sets the value of the Trigger Level element.

K_SetADTrig does not affect the operation deﬁned by hFr ame unless the Trigger Source element is set to External (by a call to K_SetTrig) before hFrame is used as a calling argument to K_IntStart.

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_SetADTrig (hAD, 0, 1, 127);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_SetADTrig (hAD, 0, 1, 127)

4-36 Function Reference

K_SetBuf

Purpose

Speciﬁes the starting address of a previously allocated buffer and the number of samples in the buffer.

Prototype C/C++

DASErr far pascal K_SetBuf (DWORD hFrame, void far *pBuf, DWORD dwSamples);

Visual Basic for Windows

Declare Function K_SetBuf Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal pBuf As Long, ByV al dwSamples As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. pBuf Starting address of buffer. dwSamples Number of samples.

Return Value

Error/status code. Refer to Appendix A.

Valid values:

1 to 131072 for the DAS-4201/128K board 1 to 524288 for the DAS-4201/512K board

Remarks

See Also

For the operation deﬁned by hFrame, this function speciﬁes the starting address of a previously allocated buffer in pBuf and the number of samples (the size of the buffer) in dwSamples.

For C/C++ programs, make sure that you use proper typecasting to prevent C/C++ type-mismatch warnings.

For Visual Basic for Windows, use this function only for dynamically allocated buffers. For locally dimensioned arrays, use K_SetBufI.

The values you specify set the following elements in the frame identiﬁed by hFrame:

● pBuf sets the value of the Buffer element.

● dwSamples sets the value of the Number of Samples element.

K_IntAlloc, K_SetBufI

4-37

K_SetBuf (cont.)

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... void far *pBuf; // Pointer to allocated buffer ... wDasErr = K_IntAlloc (hAD, 131072, &pBuf, &hMem); wDasErr = K_SetBuf (hAD, pBuf, 131072);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global pBuf As Long ... wDasErr = K_IntAlloc (hAD, 131072, pBuf, hMem) wDasErr = K_SetBuf (hAD, pBuf, 131072)

4-38 Function Reference

K_SetBufI

Purpose

Speciﬁes the starting address of a locally dimensioned integer array and the number of samples in the array.

Prototype C/C++

Not supported

Visual Basic for Windows

Declare Function K_SetBufI Lib "DASSHELL.DLL" Alias "K_SetBuf" (ByVal hFrame As Long, pBuf As Integer, ByVal dwSize As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. pBuf Starting address of the locally dimensioned

dwSize Number of samples.

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function speciﬁes the starting address of a locally dimensioned integer array in pBuf and the number of samples stored in the array in dwSize.

integer array.

Valid values: 1 to 32768

See Also

Do not use this function for C; instead, use K_SetBuf. For Visual Basic for Windows, use this function only for locally

dimensioned arrays. For buffers allocated dynamically using K_IntAlloc, use K_SetBuf.

The pBuf variable sets the value of the Buffer element; the dwSize variable sets the value of the Number of Samples element.

K_IntAlloc, K_SetBuf

4-39

K_SetBufI (cont.)

Usage Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... Global ADData(8191) As Integer ... wDasErr = K_SetBufI (hAD, ADData(0), 8192)

4-40 Function Reference

K_SetChn

Purpose

Prototype C/C++

Speciﬁes a single channel.

DASErr far pascal K_SetChn (DWORD hFrame, short nChan);

Visual Basic for Windows

Declare Function K_SetChn Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal nChan As Integer) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. nChan Channel on which to perform an analog input

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function speciﬁes the single channel used in nChan.

Software channel 0 corresponds to Channel A on the board; software channel 1 corresponds to Channel B on the board.

operation. Valid values: 0, 1

The value you specify in nChan sets the Channel element in the frame identified by hFrame.

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_SetChn (hAD, 1);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_SetChn (hAD, 1)

4-41

K_SetClk

Purpose

Prototype C/C++

Speciﬁes the pacer clock source.

DASErr far pascal K_SetClk (DWORD hFrame, short nMode);

Visual Basic for Windows

Declare Function K_SetClk Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal nMode As Integer) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. nMode Pacer clock source.

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function speciﬁes the pacer clock source in nMode. The value you specify in nMode sets the Clock Source element in the frame identiﬁed by hFrame.

K_GetADFrame and K_ClearFrame specify internal as the default clock source.

Valid values: 0 for Internal

1 for External

Usage C/C++

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_SetClk (hAD, 1);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_SetClk (hAD, 1)

4-42 Function Reference

K_SetClkRate

Purpose

Prototype C/C++

Speciﬁes the clock divider for the internal pacer clock.

DASErr far pascal K_SetClkRate (DWORD hFrame, DWORD dwDivisor);

Visual Basic for Windows

Declare Function K_SetClkRate Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal dwDivisor As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. dwDivisor Clock divider.

The following table shows the valid clock divider values and the corresponding conversion rates and sample periods for the internal pacer clock:

Valid values: See the table below.

Clock Divider

32 100 Msamples/s 10 ns

Conversion Rate

Sample Period

Return Value

64 50 Msamples/s 20 ns 128 25 Msamples/s 40 ns 256 12.5 Msamples/s 80 ns 512 6.25 Msamples/s 160 ns 1024 3.13 Msamples/s 320 ns 2048 1.56 Msamples/s 640 ns 4096 0.78 Msamples/s 1280 ns

Error/status code. Refer to Appendix A.

4-43

K_SetClkRate (cont.)

Remarks

For the operation deﬁned by hFrame, this function speciﬁes the clock divider for the internal pacer clock in dwDivisor.

The value you specify in dwDivisor sets the Pacer Clock Rate element in the frame identiﬁed by hFrame.

If you enter a clock divider value that is not one of those speciﬁed as a valid value abo ve, the dri v er uses the next f astest rate. For e xample, if you enter a clock divider value of 63, the driver uses a clock divider value of 32 to perform the faster conversion rate. To determine the actual clock divider used, use K_GetClkRate.

Refer to page 2-11 for more information on the internal pacer clock.

See Also

Usage C/C++

K_GetClkRate

#include "DASDECL.H" // Use "DASDECL.HPP for C++ ... wDasErr = K_SetClkRate (hAD, 64);

Visual Basic for Windows

(Add DASDECL.BAS or DASDEC32.BAS to your project)

... wDasErr = K_SetClkRate (hAD, 64)

4-44 Function Reference

K_SetDITrig

Purpose

Prototype C/C++

Sets up an external digital start or about trigger.

DASErr far pascal K_SetDITrig (DWORD hFrame, short nOpt, short nChan, DWORD nPattern);

Visual Basic for Windows

Declare Function K_SetDITrig Lib "DASSHELL.DLL" (ByVal hFrame As Long, ByVal nOpt As Integer, ByV al nChan As Integer, ByVal nPattern As Long) As Integer

Parameters

hFr ame Handle to the frame that deﬁnes the operation. nOpt Trigger polarity and sensitivity.

nChan Digital input channel.

nPattern Trigger pattern.

Valid values: 0 for Positive edge

2 for Negative edge

Valid value: 0

Return Value

Remarks

Error/status code. Refer to Appendix A.

For the operation deﬁned by hFrame, this function speciﬁes the trigger polarity and sensitivity in nOpt.

Since an external digital trigger is always connected to the Trigger I/O connector on the board, the value of nChan is meaningless. In addition, the DAS-4200 Series Function Call Driver does not support digital pattern triggering; therefore, the value of nPattern is meaningless. The nChan and nPattern parameters are provided for future compatibility.

The values you specify set the following elements in the frame identiﬁed by hFrame:

● nOpt sets the value of the Trigger Polarity element.

● nChan sets the value of the Trigger Channel element.

● nPattern sets the value of the Trigger Pattern element.

4-45

Tektronix Keithley DAS-4200 Series Function Call Driver Users Guide

Specifications and Main Features

Frequently Asked Questions

User Manual