Tektronix DAS-1800AO Series Users Guide

DAS-1800AO Series

User’s Guide

A GREATER MEASURE OF CONFIDENCE

WARRANTY

Hardware

Keithley Instruments, Inc. warrants that, for a period of one (1) year from the date of shipment (3 years for Models 2000,
2001, 2002, 2010 and 2700), the Keithley Hardware product will be free from defects in materials or workmanship. This
warranty will be honored provided the defect has not been caused by use of the Keithley Hardware not in accordance with
the instructions for the product. This warranty shall be null and void upon: (1) any modification of Keithley Hardware that
is made by other than Keithley and not approved in writing by Keithley or (2) operation of the Keithley Hardware outside
of the environmental specifications therefore.

Upon receiving notification of a defect in the Keithley Hardware during the warranty period, Keithley will, at its option,
either repair or replace such Keithley Hardware. During the first ninety days of the warranty period, Keithley will, at its
option, supply the necessary on site labor to return the product to the condition prior to the notification of a defect. Failure
to notify Keithley of a defect during the warranty shall relieve Keithley of its obligations and liabilities under this
warranty.

Other Hardware

The portion of the product that is not manufactured by Keithley (Other Hardware) shall not be covered by this warranty,
and Keithley shall have no duty of obligation to enforce any manufacturers' warranties on behalf of the customer. On those
other manufacturers’ products that Keithley purchases for resale, Keithley shall have no duty of obligation to enforce any
manufacturers’ warranties on behalf of the customer.

Software

Keithley warrants that for a period of one (1) year from date of shipment, the Keithley produced portion of the software or
firmware (Keithley Software) will conform in all material respects with the published specifications provided such Keithley
Software is used on the product for which it is intended and otherwise in accordance with the instructions therefore.
Keithley does not warrant that operation of the Keithley Software will be uninterrupted or error-free and/or that the Keithley
Software will be adequate for the customer's intended application and/or use. This warranty shall be null and void upon any
modification of the Keithley Software that is made by other than Keithley and not approved in writing by Keithley.

If Keithley receives notification of a Keithley Software nonconformity that is covered by this warranty during the warranty
period, Keithley will review the conditions described in such notice. Such notice must state the published specification(s)
to which the Keithley Software fails to conform and the manner in which the Keithley Software fails to conform to such
published specification(s) with sufficient specificity to permit Keithley to correct such nonconformity. If Keithley deter­mines that the Keithley Software does not conform with the published specifications, Keithley will, at its option, provide
either the programming services necessary to correct such nonconformity or develop a program change to bypass such
nonconformity in the Keithley Software. Failure to notify Keithley of a nonconformity during the warranty shall relieve
Keithley of its obligations and liabilities under this warranty.

Other Software

OEM software that is not produced by Keithley (Other Software) shall not be covered by this warranty, and Keithley shall
have no duty or obligation to enforce any OEM's warranties on behalf of the customer.

Other Items

Keithley warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes,
and documentation.

Items not Covered under Warranty

This warranty does not apply to fuses, non-rechargeable batteries, damage from battery leakage, or problems arising from
normal wear or failure to follow instructions.

Limitation of Warranty

This warranty does not apply to defects resulting from product modification made by Purchaser without Keithley's express
written consent, or by misuse of any product or part.

Disclaimer of Warranties

EXCEPT FOR THE EXPRESS WARRANTIES ABOVE KEITHLEY DISCLAIMS ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF MERCHANT­ABILITY AND FITNESS FOR A PARTICULAR PURPOSE. KEITHLEY DISCLAIMS ALL WARRANTIES WITH
RESPECT TO THE OTHER HARDWARE AND OTHER SOFTWARE.

Limitation of Liability

KEITHLEY INSTRUMENTS SHALL IN NO EVENT, REGARDLESS OF CAUSE, ASSUME RESPONSIBILITY FOR
OR BE LIABLE FOR: (1) ECONOMICAL, INCIDENTAL, CONSEQUENTIAL, INDIRECT, SPECIAL, PUNITIVE OR
EXEMPLARY DAMAGES, WHETHER CLAIMED UNDER CONTRACT, TORT OR ANY OTHER LEGAL THEORY,
(2) LOSS OF OR DAMAGE TO THE CUSTOMER'S DATA OR PROGRAMMING, OR (3) PENALTIES OR PENALTY
CLAUSES OF ANY DESCRIPTION OR INDEMNIFICATION OF THE CUSTOMER OR OTHERS FOR COSTS, DAM­AGES, OR EXPENSES RELATED TO THE GOODS OR SERVICES PROVIDED UNDER THIS WARRANTY.

Keithley Instruments, Inc.

Sales Offices: BELGIUM: Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02-363 00 40 • Fax: [phone]

CHINA: Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-6202-2886 • Fax: [phone]
FINLAND: Tietäjäntie 2 • 02130 Espoo • Phone: [phone] • Fax: [phone]
FRANCE: 3, allée des Garays • 91127 Palaiseau Cédex • 01-64 53 20 20 • Fax: [phone]
GERMANY: Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Unit 2 Commerce Park, Brunel Road • Theale • Berkshire RG7 4AB • 0118 929 7500 • Fax: [phone]
INDIA: Flat 2B, Willocrissa • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Viale San Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: [phone]
JAPAN: New Pier Takeshiba North Tower 13F • 11-1, Kaigan 1-chome • Minato-ku, Tokyo 105-0022 • 81-3-5733-7555 • Fax: [phone]
KOREA: 2FL., URI Building • 2-14 Yangjae-Dong • Seocho-Gu, Seoul 137-888 • 82-2-574-7778 • Fax: [phone]
NETHERLANDS: Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWEDEN: c/o Regus Business Centre • Frosundaviks Allé 15, 4tr • 169 70 Solna • 08-509 04 679 • Fax: [phone]
SWITZERLAND: Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: 1FL., 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3-572-9077• Fax: [phone]

28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: [phone]

1-888-KEITHLEY (534-8453) • www.keithley.com

4/02

DAS-1800AO Series

User’s Guide

Revision D - August 2000

Part Number: 91280

The information contained in this manual is believed to be accurate and reliable. However, the
manufacturer assumes no responsibility for its use; nor 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 the manufacturer.

THE MANUFACTURER SHALL NOT 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 THAT IS SUITED FOR
USE IN LIFE SUPPORT OR CRITICAL APPLICATIONS.

DriverLINX, SSTNET, and LabOBJX are registered trademarks and DriverLINX/VB is a trademark of
Scientific Software Tools, Inc.

Microsoft and Windows are registered trademarks and Visual C++ and Visual Basic are trademarks of
Microsoft Corporation.

Borland is a registered trademark and Borland C++, Delphi, and Turbo Pascal are trademarks of
Borland International, Inc.

IBM is a registered trademark of International Business Machines Corporation.

Acrobat is a registered trademark of Adobe Systems Incorporated.

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

Copyright © Keithley Instruments, Inc., 1999, 1995.

All rights reserved. Reproduction or adaptation of any part of this documentation beyond that permitted
by Section 117 of the 1979 United States Copyright Act without permission of the Copyright owner is
unlawful.

S

The following safety precautions should be observed before using this product and any associated instrumentation.
Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations
where hazardous conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety
precautions required to avoid possible injury. Read and follow all installation, operation, and maintenance information
carefully before using the product. Refer to the manual for complete product specifications.

If the product is used in a manner not specified, the protection provided by the product may be impaired.
The types of product users are:

Responsible body

the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately
trained.

Operators

of the instrument. They must be protected from electric shock and contact with hazardous live circuits.

Maintenance personnel

the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The proce­dures explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of products. Only

properly trained service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation

Category II, as described in the International Electrotechnical Commission (IEC) Standard IEC 60664. Most mea­surement, control, and data I/O signals are Installation Category I and must not be directly connected to mains voltage
or to voltage sources with high transient over-voltages. Installation Category II connections require protection for high
transient over-voltages often associated with local AC mains connections. Assume all measurement, control, and data
I/O connections are for connection to Category I sources unless otherwise marked or described in the Manual.

Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or
test fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels
greater than 30V RMS, 42.4V peak, or 60VDC are present.

age is present in any unknown circuit before measuring.

Operators of this product must be protected from electric shock at all times. The responsible body must ensure that
operators are prevented access and/or insulated from every connection point. In some cases, connections must be ex­posed to potential human contact. Product operators in these circumstances must be trained to protect themselves from
the risk of electric shock. If the circuit is capable of operating at or above 1000 volts,

may be exposed.

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance
limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards,
install protective devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect
the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

is the individual or group responsible for the use and maintenance of equipment, for ensuring that

use the product for its intended function. They must be trained in electrical safety procedures and proper use

perform routine procedures on the product to keep it operating properly, for example, setting

afety Precautions

A good safety practice is to expect that hazardous volt-

no conductive part of the circuit

5/02

When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main
input power disconnect device must be provided, in close proximity to the equipment and within easy reach of the
operator.

For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the cir­cuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting
or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as in­stalling or removing jumpers.

Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth)
ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the
voltage being measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions or the
safety of the equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and op­erating information, and as shown on the instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground con-

nections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation re-

quires the use of a lid interlock.

If or is present, connect it to safety earth ground using the wire recommended in the user documentation.

!

The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined
effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these
voltages.

The

WARNING

associated information very carefully before performing the indicated procedure.
The

CAUTION

the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the power

transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable
national safety approvals, may be used if the rating and type are the same. Other components that are not safety related
may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts
should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product.) If you
are unsure about the applicability of a replacement component, call a Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do
not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist
of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never
require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected,
the board should be returned to the factory for proper cleaning/servicing.

heading in a manual explains dangers that might result in personal injury or death. Always read the

heading in a manual explains hazards that could damage the instrument. Such damage may invalidate

Table of Contents

Preface

1

Overview

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

Supporting Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

2

Functional Description

Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

Differential/Single-Ended Selection . . . . . . . . . . . . . . . . . . . .2-3

Ground Selection for Single-Ended Inputs . . . . . . . . . . . . . . . 2-4

Unipolar/Bipolar Selection . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

Channel-Gain Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

Channel Expansion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Multiplexer Control Lines MUX 4 to MUX 7 . . . . . . . 2-5

External Gain Control Line GEXT . . . . . . . . . . . . . . . .2-6

Gains and Ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

Maximum A/D Throughput Rates . . . . . . . . . . . . . . . . . . . 2-7

Data Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

Pacer Clock Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Burst Mode Conversion Clock. . . . . . . . . . . . . . . . . . . . . 2-13

Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Pre-Trigger Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

About-Trigger Acquisition. . . . . . . . . . . . . . . . . . . . . . . . 2-16

Post-Trigger Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Gates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Data Transfer Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

Voltage Range Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

Maximum D/A Throughput Rates . . . . . . . . . . . . . . . . . . . .2-20

Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-21

Triggers and Gates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22

Data Transfer Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Digital I/O Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

Using Digital Control Signal DOSTB . . . . . . . . . . . . . . . . .2-24

iii

Using Digital Control Signals TGOUT and TGIN . . . . . . . . 2-25

Using Digital Control Signal SSHO . . . . . . . . . . . . . . . . . . .2-26

Data Transfer Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

Assigning an Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28

3

Setup and Installation

Unwrapping and Inspecting a Board . . . . . . . . . . . . . . . . . . . . . . 3-1

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

Installing the DAS-1800AO Series Standard Software

Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

Before Installing DriverLINX . . . . . . . . . . . . . . . . . . . . . . 3-3

Selecting the DriverLINX components to Install. . . . . . . . 3-3

Installing DriverLINX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Setting the Base Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Installing a Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Configuring the DAS-1800AO Board with DriverLINX. . . . . . . 3-6

4

Cabling and Wiring

Attaching an STA-1800U. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Attaching an STP-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Attaching an SSH-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6

Attaching an MB01 Backplane . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Attaching MB02 Backplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Attaching EXP-1800 Accessories . . . . . . . . . . . . . . . . . . . . . . . 4-10

Connecting Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

Precautions for Using a DAS-1801AO Board at High

Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

Additional Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

Connecting a Signal to a Single-Ended Analog Input. . . . . .4-13

Connecting a Signal to a Differential Analog Input . . . . . . . 4-13

Common Connection Schemes for Differential Inputs . . 4-13

Avoiding Ground Loops with Differential Inputs . . . . . . 4-15

Connecting Analog Output Signals. . . . . . . . . . . . . . . . . . . . 4-16

Connecting Digital I/O Signals. . . . . . . . . . . . . . . . . . . . . . . 4-16

Connecting Digital Control Signals . . . . . . . . . . . . . . . . . . . 4-16

Connecting and Synchronizing Multiple Boards . . . . . . . . . 4-17

iv

5

Testing the Board

DriverLINX Analog I/O Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Test Panel Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

6

Calibration

Equipment Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Potentiometers and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

DriverLINX Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

7

Troubleshooting

Problem Isolation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

Using the DriverLINX Event Viewer . . . . . . . . . . . . . . . . . . . 7-1

Device Initialization Error Messages . . . . . . . . . . . . . . . . . . . 7-2

Identifying Symptoms and Possible Causes . . . . . . . . . . . . . .7-2

Testing the Board and Host Computer . . . . . . . . . . . . . . . . . . 7-5

Testing the Accessory Slot and I/O Connections . . . . . . . . . . 7-5

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6

A

Specifications

B

Connector Pin Assignments

Main I/O Connector of DAS-1800AO Series Boards . . . . . . . . B-1

I/O Connectors J1 and J2 of the STA-1800U Accessory. . . . . . B-2

Connector J3 of the STA-1800U Accessory . . . . . . . . . . . . . . . B-3

Connectors J4 to J7 and Jumper Pads J8 to J11 of the

STA-1800U Accessory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

C

DriverLINX Configuration Notes

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

Calibrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

A/D Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

A/D Volts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

D/A Volts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

AI IRQ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

AI DMA 1, AO DMA 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

v

Special Device Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

Common-mode reference . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

Number of EXP-1800s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

Simultaneous sample and hold configuration . . . . . . . . . . . . C-5

Disable AO recycle mode . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

Implementation Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6

Analog Input Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-8

Analog Input Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . C-8

Internal Clocking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-9

Burst Mode Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-9

Repeat Mode Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-9

External Clocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-10

External Triggering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-10

External Gating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-10

Simultaneous Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . C-10

Analog Input Multiplexer . . . . . . . . . . . . . . . . . . . . . . . . . . C-11

Data Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-13

A/D Conversion Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-14

A/D Data Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-14

Analog Output Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-15

Analog Output Initialization . . . . . . . . . . . . . . . . . . . . . . . . C-16

Internal Clocking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-16

Synchronous Analog Input/Output Clocking . . . . . . . . . . . C-16

External Clocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17

External Triggering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17

Data Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17

D/A Conversion Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-18

D/A Data Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-19

Digital Input and Output Subsystems . . . . . . . . . . . . . . . . . . . C-20

Logical Channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-20

Digital Input Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . C-20

Digital Output Initialization . . . . . . . . . . . . . . . . . . . . . . . . C-21

Digital I/O Conversion Delay . . . . . . . . . . . . . . . . . . . . . . . C-21

Digital I/O Data Lost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21

Counter/Timer Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21

Counter/Timer Initialization . . . . . . . . . . . . . . . . . . . . . . . . C-22

Counter/Timer Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . C-22

vi

List of Figures

Figure 2-1. Block Diagram of

DAS-1800AO Series Boards . . . . . . . . . . . . . . . . . 2-2

Figure 2-2. Timing of A/D Conversion Modes

for a Queue of Channels 4 to 7 . . . . . . . . . . . . . . 2-12

Figure 2-3. Enabling Conversions with Software

Triggering/Gating and With

Internal and External Clocks . . . . . . . . . . . . . . . .2-15

Figure 2-4. Enabling Conversions with a

Hardware Trigger. . . . . . . . . . . . . . . . . . . . . . . . . 2-16

Figure 2-5. Hardware Gate. . . . . . . . . . . . . . . . . . . . . . . . . . .2-18

Figure 2-6. Timing Relationship between Data

from DO0 to DO3 and Latch Strobe DOSTB . . .2-25

Figure 2-7. Timing for the TGOUT Signal . . . . . . . . . . . . . . 2-26

Figure 2-8. Timing for SSHO Signal

When Not Used for SSH Hardware. . . . . . . . . . . 2-27

Figure 3-1. Location of Base Address Switch on

DAS-1800AO Series Boards . . . . . . . . . . . . . . . . . 3-5

Figure 4-1. Connector Layout of an STA-1800U Accessory. . 4-2
Figure 4-2. Cabling and Connections for Attaching an

STA-1800U to a DAS-1800AO Series Board. . . . 4-2

Figure 4-3. Pin Assignments for the Main I/O Connector

of a DAS-1800AO Series Board . . . . . . . . . . . . . . 4-3

Figure 4-4. Pin Assignments for Main I/O Connectors

J1 and J2 of the STA-1800U . . . . . . . . . . . . . . . . .4-4

Figure 4-5. Attaching an STP-50 to a

DAS-1800AO Series Board. . . . . . . . . . . . . . . . . . 4-5

Figure 4-6. Pin Assignments for Screw Terminals

of the STP-50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Figure 4-7. Cabling and Connections for Attaching

an SSH-8 to a DAS-1800AO Series Board . . . . . .4-6

Figure 4-8. Attaching an MB01 Backplane to a

DAS-1800AO Series Board. . . . . . . . . . . . . . . . . . 4-7

Figure 4-9. Cabling and Connections for Attaching MB02

Backplanes to an STA-1800U . . . . . . . . . . . . . . . . 4-8

Figure 4-10. Daisy-Chaining STA-1800U Accessories with

Attached MB02 Backplanes . . . . . . . . . . . . . . . . . 4-9

Figure 4-11. Daisy-Chaining EXP-1800 Accessories . . . . . . . 4-10

Figure 4-12. Connections for Wiring a Signal Source to a

DAS-1800AO Series Board Configured for

Single-Ended Inputs. . . . . . . . . . . . . . . . . . . . . . . 4-13

vii

Figure 4-13. Three Types of Connections for Wiring a

Signal Source to a DAS-1800AO Series Board

Configured for Differential Inputs. . . . . . . . . . . . 4-14

Figure 4-14. A Differential Input Configuration that

Avoids a Ground Loop . . . . . . . . . . . . . . . . . . . .4-15

Figure 4-15. Differential Input Configuration with a

Ground Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Figure 4-16. Two Connection Schemes for

Synchronizing Multiple Boards. . . . . . . . . . . . . . 4-17

Figure 6-1. Potentiometers and Test Points on the

DAS-1800AO Series Boards . . . . . . . . . . . . . . . . . 6-2

Figure B-1. Pin Assignments for the Main I/O Connector of a

DAS-1800AO Series Board. . . . . . . . . . . . . . . . . B-1

Figure B-2. Pin Assignments for Main I/O Connectors

J1 and J2 of the STA-1800U Accessory . . . . . . . B-2

Figure B-3. Pin Assignments for STA-1800U Connector J3 . B-3
Figure B-4. Pin Layouts and Assignments for STA-1800U

Connectors J4 to J7 and Jumper Pads J8 to J11. . B-4

List of Tables

Table 2-1. DAS-1801AO Gains and Ranges for

Unipolar and Bipolar Modes . . . . . . . . . . . . . . . . .2-6

Table 2-2. DAS-1802AO Gains and Ranges for

Unipolar and Bipolar Modes . . . . . . . . . . . . . . . . .2-6

Table 2-3. DAS-1800AO Series Board A/D Throughput for

Channel-to-Channel Sampling in Bipolar Mode

with Fixed Gain . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

Table 2-4. DAS-1800AO Series Board A/D Throughput

for Channel-to-Channel Sampling in

Unipolar Mode with Fixed Gain . . . . . . . . . . . . . . 2-9

Table 2-5. Maximum A/D Throughput for

DAS-1801AO in Bipolar Mode. . . . . . . . . . . . . . . 2-9

Table 2-6. Maximum A/D Throughput for

DAS-1801AO in Unipolar Mode. . . . . . . . . . . . . 2-10

Table 2-7. Maximum A/D Throughput for

DAS-1802AO in Bipolar Mode. . . . . . . . . . . . . . 2-10

Table 2-8. Maximum A/D Throughput for

DAS-1802AO in Unipolar Mode. . . . . . . . . . . . . 2-11

Table 3-1. I/O Address Map (000H to 3FFH). . . . . . . . . . . . . 3-7

Table 7-1. Troubleshooting Information. . . . . . . . . . . . . . . . . 7-3

Table A-1. Analog Input Specifications . . . . . . . . . . . . . . . . A-1

Table A-2. Analog Output Specifications . . . . . . . . . . . . . . . A-4

viii

Table A-3. Digital I/O Specifications . . . . . . . . . . . . . . . . . . A-5

Table A-4. Power Supply Requirements . . . . . . . . . . . . . . . . A-6

Table C-1. Modes Supported by DAS-1800 Models. . . . . . . C-6

Table C-2. Allowed Operations and Events for

Supported Subsystem Modes. . . . . . . . . . . . . . . . C-7

Table C-3. Table of logical channel numbers for

eight external EXP-1800 Multiplexers. . . . . . . . C-12

ix

Preface

This guide is intended to help you understand the installation, interface
requirements, functions, and operation of the DAS-1801AO and
DAS-1802AO boards. Unless this guide refers specifically to the
DAS-1801AO or DAS-1802AO board, it refers to all boards collectively
as the DAS-1800AO Series boards. At the same time, the term

Series

refers to all members of the DAS-1800 family of data acquisition

boards.

This guide focuses primarily on describing the DAS-1800AO Series
boards and their capabilities, setting up the boards and their associated
software, making typical hookups, and operating the DriverLINX
software. There are also sections on calibration and troubleshooting. To
follow the information and instructions contained in this manual, you
must be familiar with the operation of an IBM PC or compatible in the
Windows 95/98 or Windows NT environment. You must also be familiar
with data acquisition principles and their applications.

The

DAS-1800AO Series User’s Guide

is organized as follows:

DAS-1800

●

Section 1 provides an overview of the features of DAS-1800AO
Series boards, including a description of supported software and
accessories.

●

Section 2 describes operating features of the boards in more detail.
This section contains a block diagram and brief descriptions of the
features as they relate to your options for setting up and using the
boards.

●

Section 3 contains instructions for inspection, software installation,
configuration, and board installation.

xi

Section 4 shows the preferred methods for making I/O (Input/Output)

●

connections, using the available accessories and cables.

●

Section 5 Briefly describes the DriverLINX Analog I/O program and
Test program.

●

Section 6 describes how to calibrate DAS-1800 Series boards.

●

Section 7 contains information on isolating and determining the
source of operating problems. This section also contains instructions
for obtaining technical support.

●

Appendix A lists the specifications for DAS-1800AO Series boards.

Appendix B lists the pin assignments for the main I/O connectors of

●

DAS-1800AO Series boards and for the connectors of DAS-1800
Series accessories.

Appendix C contains DriverLINX configuration information for the

●

DAS-1800 Series boards.

●

An index completes this manual.

xii

1

Overview

The DAS-1800AO Series boards are multi-function data acquisition
boards that operate with DriverLINX software that requires:

an IBM PC or compatible AT (386 or Pentium CPU) with minimum

●

of 2 MB of memory.

●

at least one CD ROM drive, one fixed disk drive, and one floppy disk
drive.

●

Microsoft Windows 95/98 or Windows NT 4.0 or higher.

●

a compiler supporting Microsoft Windows development.
a mouse is highly recommended.

●

The DAS-1801AO is a 12-bit, high-gain board, while the DAS-1802AO is
a 12-bit, low-gain board. This section describes features, supporting
software, and accessories of the DAS-1800AO Series boards.

Features

Analog input features of the DAS-1800AO Series boards are as follows:

●

The board acquires data at up to 333 ksamples/s with 12-bit
resolution.

●

The board is software-configurable for 16 single-ended or 8
differential onboard channels or up to 256 differential channels using
expansion accessories.

●

Channels are individually software-configurable for gain.

●

A 1024-location FIFO (First In First Out) data buffer ensures data
integrity at all sampling rates.

Features 1-1

A 256-location channel-gain queue supports high-speed sampling at

●

the same or different gains and in sequential or non-sequential
channel order.

Burst mode data acquisition emulates simultaneous-sample-and-hold

●

(SSH) capability.

●

The boards support real-time simultaneous-sample-and-hold
capability.

●

Data transfer modes include single- or dual-channel DMA, interrupt,
or programmed I/O.

DMA and interrupt levels are software-selectable.

●

●

The polarity of hardware trigger and gate for A/D (analog-to-digital)
conversions is software-selectable.

A/D triggering supports pre-, post-, and about-trigger acquisitions.

●

Analog output features of the DAS-1800AO Series boards are as follows:

●

Analog output is available through two, 12-bit, deglitched DACs
(digital-to-analog converters).

●

Each DAC converts up to 500 ksamples/s.

●

DAC output ranges are ±5V and ±10V.
The DACs are supported by a 2048-word data FIFO.

●

●

The DACs can be updated individually or simultaneously.

●

At power-up, the DAC outputs are 0V.
The polarity of hardware trigger and gate for D/A (digital-to-analog)

●

conversions are software-selectable.

●

The analog output section can perform recycle-mode waveform
generation using the onboard FIFO.

●

The DACs can be updated by DMA, interrupt, or programmed I/O
transfers.

Digital I/O features of the DAS-1800AO Series boards are as follows:

The boards have four digital inputs.

●

●

The boards have four digital outputs with a latch strobe.

1-2 Overview

General features of the DAS-1800AO Series boards are as follows:

●

Pulsed interrupts allow multiple DAS-1800 Series boards to share
interrupt levels.

All user connections are made through a 50-pin I/O connector at the

●

rear panel of the computer.

●

All features are software-programmable except for a board’s base
address switch.

●

The boards provide ±15V power for accessories and external
circuitry.

Interrupt levels (levels 3, 5, 7, 10, 11, and 15) are software-selectable.

●

●

The boards use burst demand mode DMA for increased data transfer
throughput.

The boards make 16-bit data transfers on the AT bus.

●

For more information on these features refer to Section 2, Functional
Description.

Supporting Software

DAS-1800AO Series standard software package

●

— Shipped with
DAS-1800AO Series boards. Includes DriverLINX for Microsoft
Windows 95/98 or Windows NT and function libraries for writing
application programs under Windows in a high-level language such as
Microsoft Visual C++, Microsoft Visual Basic, Borland Delphi
support files, LabVIEW, utility programs, and language-specific
example programs.

●

DriverLINX —

the high-performance real-time data-acquisition

device drivers for Windows application development includes:

DriverLINX API DLLs

–

and drivers supporting the DAS-1800AO

Series hardware.

Analog I/O Panel —

–

A DriverLINX program that verifies the
installation and configuration of DriverLINX to your
DAS-1800AO Series board and demonstrates several virtual
bench-top instruments.

Supporting Software 1-3

–

Learn DriverLINX —

an interactive learning and demonstration
program for DriverLINX that includes a Digital Storage
Oscilloscope.

–

Source Code —
DriverLINX Application Programming Interface files —

–

for the sample programs.

application programming interface files for the DAS-1800AO
Series.

Accessories

LabVIEW support for DriverLINX —

–

application programming

interface files for the DAS-1800AO Series.

DriverLINX On-line Help System —

–

provides immediate help as

you operate DriverLINX.

Supplemental Documentation —

–

on DriverLINX installation and
configuration, analog and digital I/O programming, counter/timer
programming, technical reference, and information specific to the
DAS-1800AO Series hardware.

DAS-1800AO Series utilities —

●

The following utilities are provided

as part of both the DAS-1800AO Series standard software packages:

Analog I/O Utility —

–

DriverLINX utility used for data acquisition

and testing board operation.

Test Utility —

–

DriverLINX utility used for testing board

operation.

Calibration Utility —

–

DriverLINX utility used for calibration.

The following accessories are available for use with DAS-1800AO Series
boards:

STA-1800U

●

— screw terminal accessory. This accessory connects to
the main I/O connector of a DAS-1800AO Series board through a
CDAS-2000 cable to make all I/O signals accessible through labeled
screw terminals.

●

STP-50

— screw terminal panel. This accessory provides
general-purpose screw-terminal connections in a compact form
factor.

1-4 Overview

SSH-8

●

— An 8-channel simultaneous-sample-and-hold accessory for
the DAS-1800AO Series boards. Refer to the
more information.

SSH-8 User’s Guide

for

MB Series modules and MB01/02 backplanes

●

signal-conditioning modules and backplanes. Refer to the

User’s Guide

EXP-1800

●

for more information.

— A 16-channel expansion accessory that connects

directly to DAS-1800AO Series boards. Refer to the

User’s Guide

C16-MB1

●

for more information.

— A cable with a 37-pin, female, D-type connector and a

— Plug-in, isolated,

MB Series

EXP-1800

26-pin, female header connector for connecting an STA-1800U to an
MB01 backplane.

●

C-2600

— An 18-inch ribbon cable for connecting an STA-1800U to

an MB02 backplane.

●

C-1800

— An 18-inch ribbon cable with two 37-pin female type D

connectors for connecting an STA-1800U to an SSH-8.

●

CDAS-2000 Series

— The CDAS-2000 is a 24-inch ribbon cable for
connecting a DAS-1800AO Series board to an STA-1800U, an
STP-50, or an EXP-1800. The SDAS-2000 is a 24-inch shielded
version of the CDAS-2000.

●

CAB-50 Series

— A cable you use to form a daisy chain of
EXP-1800s; this cable is available in two lengths, as follows: the
CAB-50 is 4 inches long, and the CAB-50/1 is 18 inches long.

●

CACC-2000

— A 24-inch ribbon cable for daisy chaining additional
STA-1800U accessories to the first STA-1800U or additional
EXP-1800 accessories to the first EXP-1800.

Accessories 1-5

2

Functional Description

This section describes the features of the analog input, analog output, and
digital I/O sections of the DAS-1800AO Series boards. These
descriptions are provided to familiarize you with the operating options
and to enable you to make the best use of your board. Figure 2-1 shows
the block diagram of the DAS-1800AO Series boards.

2-1

CH 0/0

Analog

Inputs:

8 Diff.

or 16

CH 7/15

GEXT

MUX [7:4]

U_CM_MD

LL GND

DAC 0

DAC 1

Uni./Bip. Select

8 or 16

CM_MD

Inst.

Sampling

12-Bit ADC

1K x 16

A/D FIFO

Channel

Input MUX

Gain

• ADC Timing and Control

Diff./S.E.

• Interrupt Control

• ADC DMA Control

• Burst Mode Control

256 x 11

Chan.-Gain

Internal Bus

Amplifier

Sample

12-Bit

DAC 0

• DAC Timing and Control

Range Select

Range Select

• 16-Bit D/A Counter

• DAC DMA Control

Amplifier

Sample

12-Bit

DAC 1

• Recycle Mode Control

2048 x 16

Buffer

ISA AT Bus

Figure 2-1. Block Diagram of DAS-1800AO Series Boards

D GND

+5V

+5V

5V Ret.

+15V

–15V

DC/DC

+15V

15V Ret.

–15V

+5V

82C54 Counter/Timer

• 32-Bit A/D Counter

Buffe

SSHI

• About-Trigger Counter

SSHO

TGIN

TGOUT

Buffe

r

XPCLK

DI [3:0]

r

DOSTB

Latch

DO [3:0]

2-2 Functional Description

Analog Input Features

The analog input section of a DAS-1800AO Series board multiplexes all
the active input channels (up to 16 single-ended or 8 differential) down to
a single, sampling ADC (analog-to-digital converter). Sampling
resolution of the ADC is 12 bits (one part in 4096). Other features of the
analog input section include software-configurable inputs, a channel-gain
queue, data conversion modes, clock sources, trigger and gate control,
and data transfer modes. These features are described in the following
subsections.

Differential/Single-Ended Selection

Using DriverLINX software, you can set DAS-1800AO Series boards to
operate at either differential or single-ended inputs (see “DriverLINX
Configuration Notes” on page C-1). Differential inputs measure the
difference between two signals. Single-ended inputs are referred to a
common ground, also called

When you connect single-ended inputs to a DAS-1800AO Series board,
you can use the board’s LL GND (analog ground) or U_CM MD
(user-common mode) connections for your common-mode ground
reference. You specify your choice using DriverLINX (see “DriverLINX
Configuration Notes” on page C-1).

common-mode ground reference.

Generally, you want to use differential inputs for low-level signals whose
noise component is a significant part of the signal or if the signal has a
non-ground common mode. You want to use single-ended inputs for
high-level signals whose noise component is not significant.

The specific level at which one of these input configurations becomes
more effective than the other depends on the application. However, you
should use differential inputs for voltage ranges of 100mV and below.

Analog Input Features 2-3

Ground Selection for Single-Ended Inputs

When you use single-ended inputs, you have two ways of grounding input
signals: the analog ground (default) and the user-common ground. The
two schemes differ in how the low side of the instrumentation amplifier is
connected. In the default mode, the low side of the amplifier is connected
to analog ground (LL GND). In the user-common mode, the low side of
the amplifier is connected to a pin on the connector for user-common
ground (U_CM MD).

The user-common mode provides a means for eliminating ground loops
in the system by connecting the reference ground for inputs to the
U_CM MD input pin. Since the U_CM MD pin connects to the high input
impedance of the instrumentation amplifier, the signal contains no
power-supply return current.

The user-common mode also provides a means for making single-ended
measurements of signals referred to a voltage that is not ground or whose
output range does not include ground. For example, a common way to
perform 4 to 20mA current monitoring is to connect a loop with a 250
resistor to ground; the resistor yields a 1 to 5V output in this current
range. This method works but uses only 80% of the input range when
connected to a 0 to 5V range. A better way is to use a 312.5
refer all measurements to 1.25V. The actual output voltage then ranges
from 1.25V to 6.25V; however, since the amplifier low side is connected
to 1.25V, the measurement range is now a span of 5V, making the entire
input range available and increasing resolution of the measurements by
20%.

Ω

resistor and

Ω

If you use single-ended input configurations, the user-common mode is
the recommended alternative. Use the default mode only if you want the
convenience of not having to connect a separate wire for low input.

Unipolar/Bipolar Selection

Using DriverLINX, you can set the DAS-1800AO Series boards to
operate in either unipolar or bipolar input mode (see “DriverLINX
Configuration Notes” on page C-1). A unipolar signal is always positive
(0 to 5V, for example), while a bipolar signal can swing up and down
between positive and negative peak values (±5V, for example).

2-4 Functional Description

The DAS-1800AO Series boards use positive magnitude to represent
unipolar signals and 2’s complement for bipolar signals. When the input
range offers the same peak-voltage capacity for unipolar or bipolar
modes, the unipolar mode doubles the converter’s resolution.

Channel-Gain Selection

The DAS-1800AO Series boards offer up to 16 single-ended or 8
differential onboard analog input channels. Using EXP-1800 expansion
accessories, you can increase the number of inputs to 256, which are
differential only. To accommodate channel and gain settings for up to 256
inputs, the DAS-1800AO Series boards contain a RAM storage circuit for
a 256-position channel-gain queue. Each of the 256 queue positions holds
your choice of a channel number and a corresponding gain. You can enter
multiple channels sequentially or non-sequentially and with the same or
different gain codes. Channel expansion, channel sequencing control, and
available gains and input ranges for DAS-1800AO Series boards are
discussed in the following subsections.

Channel Expansion

If you require additional analog input channels, you can configure your
DAS-1800AO Series board for single-ended inputs and attach up to 16
EXP-1800 expansion accessories or up to 16 MB02 backplanes. Either
option can increase your input capacity to 256.

If you use MB02 backplanes, use one STA-1800U for every four
backplanes. Connect each group of four backplanes to an STA-1800U, as
shown in Section 4, and daisy-chain any additional STA-1800U
accessories to the first STA-1800U.

Sampling sequences and gain settings for all expansion-board channels
are communicated through the control lines described in the following
two subsections.

Multiplexer Control Lines MUX 4 to MUX 7

Multiplexer lines MUX 4 to MUX 7 control the channel sequencing of
EXP-1800 and MB01/02 expansion accessories. These lines carry the
channel-sequencing information from the channel-gain QRAM through
the main I/O connector of DAS-1800AO Series boards.

Analog Input Features 2-5

External Gain Control Line GEXT

External gain line GEXT sets channel gains on EXP-1800 accessories to
1 or 50. This line carries the channel-gain settings from the channel-gain
QRAM through the main I/O connector of the DAS-1800AO Series
boards.

Gains and Ranges

The available gains and their corresponding input ranges are listed in
Table 2-1 for the DAS-1801AO and Table 2-2 for the DAS-1802AO.

Table 2-1. DAS-1801AO Gains and Ranges for Unipolar and

Bipolar Modes

Gain Unipolar Range Bipolar Range

1 0 to 5V –5.0 to +5.0V

5 0 to 1V –1.0 to +1.0V

50 0 to 100mV –100 to +100mV

250 0 to 20mV –20 to +20mV

Table 2-2. DAS-1802AO Gains and Ranges for Unipolar and

Bipolar Modes

Gain Unipolar Range Bipolar Range

1 0.0 to +10.0V –10 to +10V

2 0.0 to +5.0V –5.0 to +5.0V

4 0 to 2.5V –2.5 to + 2.5V

8 0 to 1.25V –1.25 to +1.25V

2-6 Functional Description

Maximum A/D Throughput Rates

Because you can change input ranges on a per-channel basis, throughput
may drop if you group channels with varying gains in sequence. The drop
occurs because the channels with low-level inputs (magnitude of 100mV
or less) are slower than those with high-level inputs and because the
channels with low-level inputs must drive out the residual signals left by
the high-level inputs. The best way to maximize throughput is to use a
combination of sensible channel grouping and external signal
conditioning. When using the channel-gain queue, consider the following
suggestions:

●

Keep all channels configured for a particular range together, even if
you have to arrange the channels out of sequence.

●

If your application requires high-speed scanning of low-level signals,
use external signal conditioning to amplify the signal to ±5V or 0 to
5V. This method offers the advantages of increasing total system
throughput and reducing noise.

●

If you are not using all the channels, you can make a particular
channel-gain entry twice to allow for settling time. In this case, you
want to ignore the results of the first entry.

●

If you are measuring steady-state signals, do not use the channel-gain
queue. Instead, use software to step through the channels and perform
single-channel acquisitions. For example, use software-controlled,
single-channel acquisitions to acquire 1000 samples on channel 0 at a
gain of 1 and then 2000 samples on channel 1 at a gain of 250 to
virtually eliminate interference. This method is the best for measuring
steady-state signals even if all the channels are at the same gain.

You must give special consideration to the direct measurement of
low-level signals with the DAS-1801AO board. When using the ±20mV,
0 to 20mV, ±100mV, or 0 to 100mV ranges, measurement throughput
drops for two reasons:

The amplifier needs more time to settle to rated accuracy when

●

switching to a high gain.

●

Noise in the measurements is higher and thus can require
post-acquisition filtering (averaging) to achieve accurate results.

Analog Input Features 2-7

The DAS-1801AO has best noise performance if presented with a perfect
signal in these ranges, but perfect signals are virtually nonexistent in the
real world. Since the DAS-1801AO has very high bandwidth (bandwidth
for low-level signals is about 8 to 10MHz) any noise is amplified and
digitized. As a result, you must carry out the measurement of low-level
signals carefully to minimize noise effects.

Low-level transducers are best used with signal conditioning. Use the
±20mV, 0 to 20mV, ±100mV, and 0 to 100mV ranges with the differential
input mode.

The tables that follow show throughput for various configurations. Note
that these throughputs are based on driving the input with an ideal voltage
source. The output impedance and drive of the source are far more critical
when making large gain changes between two channels whose inputs are
at opposite extremes of their input ranges, as when a signal near

–

20mV is
measured after a signal at near +5V. You will get better performance
driving adjacent channels at the same gain. The source needs to be able to
drive both the capacitance of the cable and the RC (resistor-capacitor)
product of the multiplexer resistance and the output capacitance of the
multiplexer and board. The multiplexer is typically about 360

Ω

(1kΩ

maximum) in series with 90pF output capacitance.

On DAS-1800AO Series boards, the maximum throughput for sampling
one channel at any gain is 333 ksamples/s. The throughput for
channel-to-channel sampling with fixed gain in bipolar mode (0.024%
maximum error) is shown in Table 2-3.

Table 2-3. DAS-1800AO Series Board A/D Throughput for Channel-to-Channel

Sampling in Bipolar Mode with Fixed Gain

DAS-1801AO Input Range DAS-1802AO Input Range Throughput

— ±10.0V 312.5 ksamples/s

±5.00V ±5.00V 312.5 ksamples/s

— ±2.50V 312.5 ksamples/s

— ±1.25V 312.5 ksamples/s

±1.00V — 312.5 ksamples/s

±100mV — 312.5 ksamples/s

±20mV — 75 ksamples/s

2-8 Functional Description

The throughput for channel-to-channel sampling with fixed gain in
unipolar mode (0.024% maximum error) is shown in Table 2-4.

Table 2-4. DAS-1800AO Series Board A/D Throughput for Channel-to-Channel

Sampling in Unipolar Mode with Fixed Gain

DAS-1801AO Input Range DAS-1802AO Input Range Throughput

— 0 to 10.0V 312.5 ksamples/s

0 to 5.00V 0 to 5.00V 312.5 ksamples/s

— 0 to 2.50V 312.5 ksamples/s

— 0 to 1.25V 312.5 ksamples/s

0 to 1.00V — 312.5 ksamples/s

0 to 100mV — 250 ksamples/s

0 to 20mV — 60 ksamples/s

The maximum throughput for a DAS-1801AO board, operating in bipolar
mode and having less than 1 LSB of error when driven from an ideal
voltage source, is shown in Table 2-5.

Table 2-5. Maximum A/D Throughput for DAS-1801AO in Bipolar Mode

Maximum Throughput

To ±5V To ±1.0V To ±100mV To ±20mV

From ±5.0V
From ±1.0V
From ±100mV
From ±20mV

Analog Input Features 2-9

312.5 ksamples/s 250 ksamples/s 200 ksamples/s 70 ksamples/s

250 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 70 ksamples/s

200 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 70 ksamples/s

70 ksamples/s 70 ksamples/s 70 ksamples/s 75 ksamples/s

The maximum throughput for a DAS-1801AO board, operating in
unipolar mode and having less than 1 LSB of error when driven from an
ideal voltage source, is shown in Table 2-6.

Table 2-6. Maximum A/D Throughput for DAS-1801AO in Unipolar Mode

Maximum Throughput

To 0 to 5V To 0 to 1.0V To 0 to 100mV To 0 to 20mV

From 0 to 5.0V
From 0 to 1.0V
From 0 to 100mV
From 0 to 20mV

312.5 ksamples/s 200 ksamples/s 200 ksamples/s 50 ksamples/s

200 ksamples/s 312.5 ksamples/s 250 ksamples/s 60 ksamples/s

200 ksamples/s 250 ksamples/s 250 ksamples/s 60 ksamples/s

50 ksamples/s 60 ksamples/s 60 ksamples/s 60 ksamples/s

The maximum throughput for a DAS-1802AO board, operating in bipolar
mode and having less than 1 LSB of error when driven from an ideal
voltage source, is shown in Table 2-7.

Table 2-7. Maximum A/D Throughput for DAS-1802AO in Bipolar Mode

Maximum Throughput

To ±10.0V To ±5.0V To ±2.50V To ±1.25V

From ±10.0V
From ±5.0V
From ±2.50V

312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s

312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s

312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s

From ±1.25V

2-10 Functional Description

312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s 312.5 ksamples/s

The maximum throughput for a DAS-1802AO board, operating in
unipolar mode and having less than 1 LSB of error when driven from an
ideal voltage source, is shown in Table 2-8.

Table 2-8. Maximum A/D Throughput for DAS-1802AO in Unipolar Mode

Maximum Throughput

To 0 to 10.0V To 0 to 5.0V To 0 to 2.5V To 0 to 1.25V

From 0 to 10.0V
From 0 to 5.0V
From 0 to 2.5V
From 0 to 1.25V

312.5 ksamples/s 312.5 ksamples/s 250 ksamples/s 200 ksamples/s

312.5 ksamples/s 312.5 ksamples/s 250 ksamples/s 200 ksamples/s

250 ksamples/s 250 ksamples/s 312.5 ksamples/s 200 ksamples/s

200 ksamples/s 200 ksamples/s 200 ksamples/s 312.5 ksamples/s

Data Conversion Modes

The analog input section of DAS-1800AO Series boards support two
modes of A/D data conversion: paced and burst. The conversion rate for
each of these two modes is controlled by a different clock: the pacer clock
for paced mode and the burst mode conversion clock for burst mode.
Other differences between the two data conversion modes are as follows:

●

Paced mode

is the mode best-suited for continuous scanning of a queue of
channels at a constant rate. In the paced mode, the conversion rate
equals the pacer clock rate. The sample rate, which is the rate at
which a single channel is sampled, is the pacer clock rate divided by
the number of channels in the queue.

— Paced mode is the default data conversion mode and

●

Burst mode

— In burst mode, each pulse from the pacer clock starts
a scan of a queue of channels. The conversion rate during a burst
mode scan is equal to the rate of the burst mode conversion clock.
The sample rate, which is the rate at which a single channel is
sampled, is equal to the pacer clock rate. Burst mode can also be used
for pseudo-simultaneous-sample-and-hold in conjunction with DMA
or interrupt operations.

Analog Input Features 2-11

Pacer Clock

Figure 2-2 shows the timing relationships of the paced and burst modes
for a queue of channels 4 to 7.

Paced Mode Conversions

Burst Mode Conversions

Burst Mode Conversions
(with SSH-8)

Burst Mode Conversion Clock

CH4

CH4

CH5

CH4Hold

CH6

CH5

CH7

CH6

CH5

CH4 CH5

CH4

HoldCH7

Figure 2-2. Timing of A/D Conversion Modes for a Queue of Channels 4 to 7

Clock Sources

DAS-1800AO Series boards provide two clocks for A/D conversions: a
pacer clock and a burst mode conversion clock. In paced mode, the pacer
clock works alone to time interrupt-mode and DMA-mode operations; in
burst mode and burst mode with SSH, the pacer clock and the burst mode
conversion clock work together to time interrupt-mode and DMA-mode
operations. The timing for these two modes is illustrated in Figure 2-2.
The paced mode and burst mode conversion clock sources are described
in the following subsections.

Pacer Clock Sources

CH6

CH5

CH7

CH6

CH7

The following clock sources can be used by DAS-1800AO Series boards
for A/D paced mode conversions:

●

Software

— DAS-1800AO Series boards allow you to acquire single

or multiple samples under program control.

●

Hardware (internal)

— The internal pacer clock uses the onboard
82C54 counter/timer and a crystal-controlled 5MHz time base. The
internal pacer clock is programmable between a maximum rate of
333kHz and a minimum rate of 0.0012Hz. When not used to pace the
analog input, the internal clock can serve to pace other events such as
the digital I/O through the use of interrupts. The internal A/D pacer
clock can also serve to pace D/A conversions (during simultaneous
A/D sampling and D/A conversions).

2-12 Functional Description

Hardware (external)

●

— An external pacer clock must be a
TTL-compatible signal attached to XPCLK (pin 44) of the main I/O
connector (pin 44 of the main I/O connector is accessible through pin
38 of STA-1800U connectors J1 and J2). The active edge for this
clock is programmable.

An external clock is useful if you want to pace at rates not available
with internal clocking, if you want to pace at uneven intervals, or if
you want to pace on the basis of an external event. An external clock
also allows you to synchronize multiple boards with a common
timing source (see “Connecting and Synchronizing Multiple Boards”
on page 4-17).

Note:

The ADC acquires samples at a maximum of 333 ksamples/s (one
sample every 3.0µs). If you are using an external clock, make sure that it
does not initiate conversions at a faster rate than the ADC can handle.

If you are acquiring samples from multiple channels, the maximum
sampling rate for each channel is equal to the maximum allowable
conversion rate divided by the number of channels (see “Maximum A/D
Throughput Rates” on page 2-7).

Burst Mode Conversion Clock

In burst mode and burst mode with SSH, the internal burst mode
conversion clock determines the A/D conversion rate, while the pacer
clock (internal or external) determines the rate at which bursts occur. In
this manual, the conversion rate during burst mode conversion is referred
to as the
referred to as the

DAS-1800 Series software allows you to program the A/D pacer clock to
adjust the interval between scans. This software also allows you to adjust
the burst mode conversion rate. The burst mode conversion clock
frequency is programmable for a range of 15.625kHz to 333 kHz (64µs to
3µs in 1µs increments).

Analog Input Features 2-13

burst mode conversion rate

scan rate

.

, and the rate at which bursts occur is

Triggers

The sample rate (pacer clock rate) should be set for no more than the burst
mode conversion clock rate divided by the number of channels in the
burst. The maximum burst mode conversion clock rate is gain-sensitive,
as explained in “Maximum A/D Throughput Rates” on page 2-7.

With the SSH-8 attached to a DAS-1800AO Series board, the sample rate
(pacer clock rate) can be no more than the burst mode conversion rate
divided by the sum of one plus the number of channels in the burst. For
information on the signal interface between a DAS-1800AO Series board
and SSH-8, refer to “Using Digital Control Signal SSHO” on page 2-26.

A trigger can start or stop an interrupt-mode or DMA-mode analog input
operation. An operation can use either one or two triggers. Every
operation must have a
operation. You can use an optional second trigger, the

start trigger

that marks the beginning of an

about trigger

, to
define when an operation stops. You can use one of the following trigger
sources to start an analog input operation:

●

Internal

— When you enable the analog input operation, conversions

begin immediately.

●

External Analog

— While a hardware analog trigger is not a
hardware function of the DAS-1800AO Series boards, you can
program an analog trigger using one of the analog input channels as
the trigger channel. The DAS-1800AO Series DriverLINX software
provides functions for an analog trigger; refer to “DriverLINX
Configuration Notes” on page C-1 and the DriverLINX on-line
documentation provided with your DAS-1800AO Series board.

External Digital

●

— Connect the digital trigger to TGIN (pin 46) of
the main I/O connector (pin 46 of the main I/O connector is
accessible through pin 42 of STA-1800U connectors J1 and J2).
Trigger types are as follows:

P ositive-edg e trigger

–

- Triggering occurs on the rising edge of the

trigger signal.

Negative-edge trigger

–

- Triggering occurs on the falling edge of

the trigger signal.

2-14 Functional Description

The actual points at which conversions begin depend on whether the
clock source is internal or external, as follows:

●

Internal Clock

— The 82C54 counter/timer is idle until the trigger
occurs. Within 400ns, the first conversion begins. Subsequent
conversions are synchronized to the internal clock. An internal clock
can be used with an internal gate, an external trigger, or an external
gate.

●

External Clock

— Conversions are armed when the trigger occurs;
they begin with the next active edge of the external clock and
continue with subsequent active edges. An external clock can be used
with an internal gate, an external trigger, or an external gate.

The polarity of external triggers in the DAS-1800AO Series boards is
software-selectable. Figure 2-3 illustrates the enabling of conversions
with software triggering/gating and with internal and external clock
sources. In the diagram, the software enabling of the conversion process
represents the point at which the computer issues a write to allow
conversions. The delay shown between that point and startup of the
onboard clock is less than 1µs. Figure 2-4 illustrates the enabling of
conversions with a hardware trigger.

Software enables
conversion process

External clock source

Internal clock source

Conversions begin with
internal clock source

idle state

count

Conversions begin with
external source (programmed
for negative edge)

count

count

count

Figure 2-3. Enabling Conversions with Software Triggering/Gating and With

Internal and External Clocks

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. As described in the following subsections, availability of the

Analog Input Features 2-15

about trigger provides the capability to define operations that acquire data
before a trigger (pre-trigger acquisition), operations that acquire data
before and after a trigger (about-trigger acquisition), and operations that
acquire data after a trigger (post-trigger acquisition).

Trigger occurs (on positive edge)

TGIN input

Conversions begin with
external source (programmed
for negative edge)

External clock

Internal clock

Conversions begin with
internal clock

Figure 2-4. Enabling Conversions with a Hardware Trigger

Pre-Trigger Acquisition

In pre-trigger acquisition, the data of interest appears before a specific
digital trigger. Acquisition starts on an internal, analog, or digital trigger
and continues until the digital-trigger. Pre-trigger acquisition is available
with DMA-mode operations only.

About-Trigger Acquisition

In about-trigger acquisition, the data of interest appears both before and
after a specific digital trigger. Acquisition starts on an internal, analog, or
digital trigger and continues until a specified number of samples has been
acquired after the digital trigger. About-trigger acquisition is available
only with DMA-mode operations.

idle state

count

count

count

count

2-16 Functional Description

Post-Trigger Acquisition

In post-trigger acquisition, the data of interest appears after a specific
event. Acquisition starts on an internal, analog, or digital trigger and
continues until a specified number of samples has been acquired or until
the operation is stopped by software.

Gates

A gate in the active state allows conversions to proceed. Connect the
external gate to TGIN (pin 46) of the main I/O connector.

The way conversions are synchronized depends on whether you are using
an internal or an external clock, as follows:

●

With internal clocking

signal goes inactive. When the gate signal goes active, the 82C54 is
reloaded with its initial count value and starts counting again;
therefore, with internal clocking, conversions are synchronized to the
gate signal.

— The 82C54 stops counting when the gate

With external clocking

●

— The signal from the external clock
continues uninterrupted while the gate signal is inactive; therefore,
with external clocking, conversions are synchronized to the external
clock.

Analog Input Features 2-17

Figure 2-5 illustrates the use of the hardware gate with both an external
clock and an internal clock.

Digital trigger
and gate
source

External
clock

Internal
clock

1st conversion

Data T ransfer Modes

gate active;
conversions on

1st conversion

3rd conversion

2nd conversion

2nd conversion

Figure 2-5. Hardware Gate

gate inactive;
conversions off

no conversion

4th conversion

gate active

3rd conversion

Using the appropriate software, you can transfer data from the
DAS-1800AO Series boards to the computer using the following data
transfer modes:

●

Single

— In single mode, the board is driven by software to acquire

and convert a single sample from an analog input channel.

●

Interrupt — An interrupt is generated when the board needs to
transfer data to the computer. Interrupts are also generated by the
following events: FIFO not full, FIFO half full, about-trigger terminal
count, data overflow, and end of DMA transfer.

An interrupt occurs in the background, allowing the CPU to execute
other instructions. The interrupt level is software-selectable.

2-18 Functional Description

Unpredictable interrupt latencies in the Windows environment can
make maximum board speeds unachievable in the interrupt mode.
When in the Windows environment, you are advised to use single- or
dual-channel DMA instead of the interrupt transfer mode.

● DMA — DMA is a method of bypassing the CPU to transfer data

directly between an I/O device and computer memory. In the IBM PC
AT family, DMA is directed by the DMA controllers and can run in
the background while the CPU is executing other instructions. The
ability to run independent of the CPU and at high-transfer rates
makes DMA an attractive method for transferring data in data
acquisition systems.

DAS-1800AO Series boards use DMA channels 5, 6, and 7 to
perform single- or dual-channel DMA transfers of A/D data from the
board to memory. When you set up your configuration file, you can
specify these channels individually for single-channel DMA or in
pairs for dual-channel DMA.

Each DMA channel can transfer up to 65,536 A/D samples before it
has to be reprogrammed with a new memory address. When more
than 65,536 samples are required by an application, the FIFO
automatically buffers the samples while the DMA channel is being
re-programmed for another address. In most situations, this FIFO
buffering capability allows you to acquire large amounts of gap-free
data into multiple buffers at up to maximum board speed using a
single DMA channel.

Generally, if you are programming operations in the Windows
Enhanced mode, you should use dual-channel DMA to acquire data
reliably at maximum board speeds.

Analog Output Features

The analog output section of a DAS-1800AO Series board contains two
12-bit DACs with bipolar outputs. Each DAC is deglitched (a glitch is a
transient that can occur during certain types of voltage changes). You can
update the DACs individually or simultaneously by writing a data word to
each DAC or by using interrupts or DMA.

Analog Output Features 2-19

You can pace analog output conversion with an internal or external clock
and an internal or external trigger/gate. Analog output pacing can be
synchronous with or independent of analog input pacing.

A 2048 x 16 location FIFO provides a buffer storage for the analog
output. The analog output’s Recycle mode allows you to generate a
waveform based on continuous duplication of the contents of this FIFO.
Recycle mode can work with FIFO contents in a range of 2 to 2048
samples. The waveform can be generated at maximum rate and without
burdening the computer bus with data transfers.

Analog output features are discussed in the following subsections.

Voltage Range Selection

Each DAC has bipolar output voltage ranges of ±5V and ±10V. The
ranges are software-selectable. The DAC outputs power up to 0V at reset.

Maximum D/A Throughput Rates

The maximum achievable throughput rate of each DAC is specified as
500 ksamples/s. Actual rates may be reduced by the factors of settling
time and data transfer mode.

Settling time can reduce throughput when a DAC must convert voltage
swings at or close to full scale (±5V or ±10V). Each DAC and its
associated circuitry require more time to settle from a large voltage
swing. A typical DAC settling time for a 20V (±10V) swing is 3µs, which
equates to a DAC throughput of 333 ksamples/s.

Settling time can also reduce throughput for small voltage steps when the
input code represents a voltage step that puts a DAC through a major
transition (from the digital code 1000 0000 0000 to the digital code
0111 1111 1111). This transition produces a glitch that requires a
significant settling time. While the DACs contain circuitry to remove
glitches from the output, the effect on settling time remains. A typical
DAC settling time for a major transition is less than 2µs, which equates to
a maximum throughput of 500 ksamples/s.

2-20 Functional Description

Clock Sources

Data transfer modes (see “Data Transfer Modes” on page 2-23) affect
throughput by the nature of their operation and their use of the computer
bus. Recycle mode is the fastest of the data transfer modes. Recycle mode
allows waveforms of up to 2048 samples to recycle in onboard memory
and does not require use of the computer bus. Throughput rates for
recycle mode easily reach 500 ksamples/s for each DAC.

The DMA data transfer mode uses the computer bus. This mode allows
combined throughput rates of up to 500 ksamples/s for the two DACs.

The interrupt data transfer mode also uses the computer bus. This mode is
useful for combined throughput rates of less than 200 ksamples/s for the
two DACs.

You can initiate analog output conversions one-at-a-time through program
control or continuously by one of three hardware clocks. Clock sources
for these conversions are discussed as follows:

● Software — Program control allows the conversion of single or

multiple samples and is useful for very slow or DC applications.

● Hardware (internal) — The internal clock consists of a 16-bit

counter with optional divide-by-ten prescaler driven by a 5 MHz
crystal oscillator. The internal clock is programmable between a
maximum rate of 500 kHz and a minimum rate of 7.63 Hz.

● Hardware (external) — The external clock must be an externally

applied TTL-compatible signal attached to XPCLK (pin 44) of the
main I/O connector (pin 44 of the main I/O connector is accessible
through pin 38 of STA-1800U connectors J1 and J2). The external
clock for the analog input section also uses XPCLK. The active edge
for this clock is programmable.

An external clock is useful if you want to pace at rates not available
with internal clocking, if you want to pace at uneven intervals, or if
you want to pace on the basis of an external event. An external clock
also allows you to synchronize multiple boards with a common
timing source (see “Connecting and Synchronizing Multiple Boards”
on page 4-17).

Analog Output Features 2-21

● Hardware (internal A/D clock) — This source is the pacer clock

(see “Clock Sources” on page 2-12). Using this clock to pace D/A as
well as A/D conversions allows you to perform tightly coupled
stimulus-response operations at rates of up to 333 ksamples/s.

Triggers and Gates

There are several options for starting and stopping D/A conversions when
pacing with a hardware clock. Conversions can be enabled through
program control or through an external hardware trigger or gate.
Conversions can be disabled through program control or through an
external hardware gate. In addition, you can continuously retrigger a
waveform running in recycle mode to its beginning using an external
hardware trigger. Refer to “Data Transfer Modes” on page 2-23 for
information on recycle mode. Trigger types are as follows:

– P ositive-edge trigg er - Triggering occurs on the rising edge of the

– Negative-edge trigger - Triggering occurs on the falling edge of

Available trigger/gate sources and their applications are as follows:

trigger signal.

the trigger signal.

● Internal Trigger — You can use software (program) control to

enable or disable analog output conversions. D/A conversions begin
about 1µs after the computer issues the necessary write while using
an internal hardware clock or begin on the next active edge of an
external clock.

● External Trigger — You can start analog output conversions by

connecting a trigger signal to the TGIN (pin 46) input of the main I/O
connector. This input is TTL-compatible and is shared with the
analog input section. The active edge of this signal is programmable.
Conversions begin about 400ns after the active edge of an external
trigger when using an internal hardware clock or on the next active
edge of an external clock. The DAS-1800 Series DriverLINX
program provides functions for an analog trigger; refer to
“DriverLINX Configuration Notes” on page C-1 and the DriverLINX
on-line documentation provided with your DAS-1800AO Series
board.

2-22 Functional Description

● Retrigger — When using the recycle mode, a waveform stored in the

onboard memory can be continuously retriggered from some point
before its end to its beginning using an external signal connected to
the TGIN input on pin 46 of the main I/O connector. The active edge
of the external signal is programmable.

● External Gate — You enable analog output conversions only while a

signal connected to the TGIN (pin 46) input of the main I/O
connector is active. This input is TTL-compatible and is shared with
the analog input section. The polarity of the signal is programmable.
When using an internal hardware clock, D/A conversions begin about
400ns after an external gate becomes active and terminate when the
gate signal becomes inactive. When using an external clock, D/A
conversions begin on the next active clock edge after an external gate
becomes active and terminate when the gate signal becomes inactive.

Data T ransfer Modes

DAS-1800AO Series boards support the following data transfer modes for
the analog output section:

● Single — In single mode, the software driver writes a single value to

one analog output channel.

● Interrupt — DAS-1800AO Series boards support the following

interrupt levels for the transfer of data to the analog output section: 3,
5, 7, 10, 11, and 15. The levels are software-selectable. An interrupt at
the selected level is generated for such events as data underflow,
DMA terminal count, FIFO not full, and FIFO not half full.

● DMA — DAS-1800AO Series boards support the following DMA

channels for the transfer of data to the analog output section: 5, 6, and

7. You select a single DMA channel for D/A data transfers.

● Recycle — In recycle mode, a waveform of 2 to 2048 samples is

loaded into D/A FIFO memory. This waveform cycles to the DAC
output continuously at a rate determined by the number of samples in
the waveform and the rate of the D/A clocking source.

If an output waveform from a DAC is repetitive and is less than or equal
to 2048 samples, the recommended mode is recycle. Recycle mode does
not use the computer bus during waveform generation and is therefore
independent of bus speeds and the operating environment (Windows).
Output rates of 500 ksamples/s are achievable by each DAC.

Analog Output Features 2-23

If an output waveform from a DAC is non-repetitive or contains more
than 2048 samples, the recommended mode is interrupt or DMA; these
modes are typically used by the analog input section, as well.

Note: Actual throughput of the analog output section also depends on the

data transfer rate of the analog input, your computer, and any other
processes occurring at the same time.

Under Windows, DMA data transfers are recommended; they produce
typical throughputs of 333 ksamples/s (and up to 500 ksamples/s).

Digital I/O Features

DAS-1800AO Series boards contain four digital inputs (DI0 to DI3) and
four digital outputs (DO0 to DO3). Logic 1 on an I/O line indicates that
the input/output is high (greater than 2.0V); logic 0 on an I/O line
indicates that the input/output is low (less than 0.8V). The digital inputs
are compatible with TTL-level signals. These inputs are provided with
10kΩ pull-up resistors to +5V; therefore, the inputs appear high (logic 1)
with no signal connected.

Using Digital Control Signal DOSTB

The DAS-1800AO Series boards provide strobe signal DOSTB (on
pin 19) for the purpose of strobing data through the digital outputs and
latching the data into a register in external equipment. Where
DAS-1800AO Series boards use the positive edge of the strobe to strobe
data out, you must use the negative edge to strobe data into other
equipment because the negative edge gives you a 300ns lag to allow for
delays. Data is valid until the next strobe, as shown in Figure 2-6.

2-24 Functional Description

300ns Strobe

DOSTB

DO[3:0] Data

Figure 2-6. Timing Relationship between Data from DO0 to DO3 and

Latch Strobe DOSTB

Using Digital Control Signals TGOUT and TGIN

You can use the trigger/gate output TGOUT (on pin 20) signal only when
the onboard pacer clock is used to time conversions. Use TGOUT to
synchronize other DAS-1800 Series boards or to trigger or gate
user-specific events as follows:

● When using digital control signal TGIN as a trigger, TGOUT behaves

as shown in Figure 2-7a. Note that when you use this option, TGOUT
does not retrigger and thus cannot be used with about-trigger
acquisitions. Note also that there is a delay of about 200 ns between
the active edge of TGIN and the starting edge of TGOUT.

Strobe

● When using digital control signal TGIN as a gate, TGOUT behaves as

shown in Figure 2-7b. Note that there is a delay of about 200ns
between the active edge of TGIN and the starting edge of TGOUT.

● When using an internal trigger/gate, TGOUT behaves as shown in

Figure 2-7c. Note that the delay between the active edge of the
internal trigger/gate and the starting edge of TGOUT is less than 1µs.

Digital I/O Features 2-25

TGIN

TGOUT

200ns typical

a. TGIN as a Trigger

Remains active until
conversions are
disabled by software

TGIN

TGOUT

Software enables
conversions

Internal
Trigger/Gate

TGOUT

200ns typical

b. TGIN as a Gate

< 1µs

c. Internal Trigger/Gate

Figure 2-7. Timing for the TGOUT Signal

Using Digital Control Signal SSHO

The SSHO digital control signal is normally generated by DAS-1800AO
Series boards to accommodate external SSH hardware. The SSHO signal
is initiated by either the onboard counter/timer clock or a user-supplied
external clock. Characteristics of the SSHO signal when used for SSH
hardware control are as follows:

Software disables
conversions

● SSHO is normally low, signifying that the SSH hardware is in sample

mode.

● SSHO goes high (into the Hold mode) about 50ns after an active edge

of the pacer clock and remains there until 200ns after the ADC starts
conversion of the last channel in the burst.

● SSHO remains low until another active edge of the pacer clock. To

ensure adequate sample time for the SSH hardware, the pacer clock
period should be set as follows:

Pacer Clock Period ≥ (Number of Channels + 1) × (Burst Period)

2-26 Functional Description

The burst period can be 3.0 to 64µs. A/D conversion begins one burst
period after an active edge of the sample clock. Burst mode must be
used when the SSH-8 is connected to DAS-1800AO Series boards.

When you are not using the SSHO signal for SSH-8 control, you can use
it as a converter clock output signal. SSHO is active only during A/D
conversions. The timing for SSHO generation when the DAS-1800AO
Series boards are not used for control of SSH hardware is shown in
Figure 2-8.

active edge

External Clock

300ns typical

SSHO

a. SSHO with External Clock

Internal Clock

300ns typical

SSHO

b. SSHO with Internal Clock

Figure 2-8. Timing for SSHO Signal When Not Used for SSH

Hardware

Data T ransfer Modes

You can perform digital I/O operations in one of the following data
transfer modes:

● Single — In a single-mode digital input operation, the software driver

reads the value of digital input channel 0 once. In a single-mode
digital output operation, the software driver writes a value to digital
output channel 0 once.

● Interrupt — In an interrupt-mode digital input operation, the

software driver reads the value of digital input channel 0 multiple
times. In an interrupt-mode digital output operation, the software
driver writes a single value or multiple values to digital output
channel 0 multiple times.

Digital I/O Features 2-27

Assigning an Interrupt

You assign an interrupt level to a DAS-1800 Series board through the
DriverLINX software configuration (see “DriverLINX Configuration
Notes” on page C-1). When you install more than one board in a
computer, you assign interrupt levels to the boards in one of the following
ways:

● You can assign a different interrupt level to each board (if enough

levels are available).

● You can assign the same interrupt level to some boards and different

interrupt levels for each of the remaining boards.

Note: Some computers can accept as many as three DAS-1800HC

boards.

● You can assign one interrupt level to be shared by all boards.

If a DAS-1800 Series board is sharing an interrupt level with one or more
other DAS-1800 Series boards and requests an interrupt, the DriverLINX
software determines the source of the request by scanning each board
until the interrupt request flag is located. DriverLINX then signals the
computer to respond accordingly.

Power

DAS-1800AO Series boards use the +5V and the +12V provided by your
computer. An onboard DC/DC converter develops ±15V at a maximum
current draw of 30mA for external use. In addition to the ±15V, the
DAS-1800AO Series boards supply +5V from the computer to pins 24
and 49 on the main I/O connector at up to a maximum of 1.0A.

2-28 Functional Description

Setup and Installation

This section describes inspection, software installation, configuration,
and hardware installation for the DAS-1800AO Series boards.

Read this section before you attempt to install and use your DAS-1800AO
Series board.

Unwrapping and Inspecting a Board

3

Caution:

performing the following procedure.

After you remove the wrapped board from its outer shipping carton,
proceed as follows:

1. The board is packaged at the factory in an anti-static wrapper that

2. Carefully unwrap the board from its anti-static wrapping material.

Unwrapping and Inspecting a Board 3-1

Your computer must be turned OFF and grounded before

must not be removed until you have discharged any static electricity
by either of the following methods:

– If you are equipped with a grounded wrist strap, you discharge

static electricity as soon as you hold the wrapped board.

– If you are not equipped with a grounded wrist strap, discharge

static electricity by holding the wrapped board in one hand while
placing your other hand firmly on a metal portion of the computer
chassis.

(You may store the wrapping material for future use.)

3. Inspect the board for signs of damage. If damage is apparent, arrange
to return the board to the factory (see “Technical Support” on
page 7-6).

4. Check the remaining contents of your package against the packing
list to be sure your order is complete. Report any missing items,
immediately.

5. When you are satisfied with the inspection, proceed with the software
and hardware setup instructions.

Note:

DAS-1800AO Series boards are factory calibrated; they require no
further adjustment prior to installation. If at a later time you decide to
recalibrate the board, refer to Section 6 for instructions.

Installing the Software

Caution:

new hardware, exit all other programs. If you are using a disk cache,
disable write caching. If the system does crash and you are using disk
compression software or a disk cache utility, run the utility that checks the
directory structures.

To prevent a system crash the first time you install and test any

Installing the DAS-1800AO Series Standard Software Package

Important:

DAS-1800AO, read the

Guide
Keithley DAS-1800

software. They are accessed from the DriverLINX CD-ROM after you
have installed Adobe Acrobat.

3-2 Setup and Installation

Before you begin installing any hardware or software for the

DriverLINX Installation and Configuration

and the

Appendix F: Configuration and Implementation Notes—for

manuals that are packaged with the DriverLINX

Before Installing DriverLINX

1. Inventory your DAS-1800AO board’s configuration settings.

2. Determine the resources your DAS-1800AO Series board requires.

3. Inventory your computer’s resources already allocated to other

installed devices.

4. Determine whether your computer has sufficient resources for your

DAS-1800AO board.

5. Determine whether your DAS-1800AO board can use your

computer’s free resources.

6. Set any jumpers/switches to configure your DAS-1800AO board to

use your computer’s free resources.

7. Set any other jumpers/switches to configure your DAS-1800AO

board the way you want it to operate. Make a note of the switch and
jumper settings in order to configure the board using DriverLINX.

Selecting the DriverLINX components to Install

For your convenience in installing and uninstalling the DriverLINX
components you need, the DriverLINX CD Browser will assist you in
selecting the components to install:

●

Install Drivers —

This required component installs only the files you
need for configuring your hardware and running third–party
data–acquisition applications that require DriverLINX.

●

Install Interfaces —

This optional component installs the files and
example programs that you will need to develop custom applications
for DriverLINX using C/C++, Visual Basic, Delphi, and LabVIEW.

●

Install LabVIEW —

This component installs the files and programs
that you will need to develop applications for DriverLINX using
LabVIEW.

●

Install Documentation

— This optional component installs
electronic documentation for DriverLINX that you can read, search,
and print using the Adobe Acrobat Reader.

●

Install Acrobat —

This optional component installs the Adobe

Acrobat Reader for the DriverLINX electronic documentation.

Installing the Software 3-3

Installing DriverLINX

1. Insert the DriverLINX CD-ROM into your computer’s CD-ROM
Drive.

2. Start the DriverLINX setup program. On most systems, wait a few
seconds for automatic startup. Otherwise, run the setup.exe program
from the CD-ROM.

3. The DriverLINX CD-ROM Browser Map window appears on the
screen. Click ‘Install Drivers,’ and follow the series of on-screen
instructions.

Note:

To display an explanation of a menu option on the DriverLINX CD
browser map that appears next and on subsequent setup screens, place the
mouse pointer over the menu item. A star next to a menu item means that
the item was selected previously.

4. Select ‘Read Me First,’ and follow the instructions.

5. Select ‘Install Documentation.’ If you do not have Adobe Acrobat

installed on your computer, install it by selecting ‘Install Adobe
Acrobat.’

6. Open the manuals appropriate to the DAS-1800 installation and read

them before installing your DAS-1800 board or configuring
DriverLINX:

●

Installation and Configuration
Appendix F: Configuration and Implementation Notes—for Keithley

●

DAS-1800.

●

DriverLINX Technical Reference Manual
DriverLINX Analog I/O Programming Guide

●

●

DriverLINX Digital I/O Programming Guide

●

DriverLINX Counter/Timer Programming Guide

●

Appendix, I/O Port, Interrupt, and DMA Channel Usage

Other manuals appropriate to your installation.

●

3-4 Setup and Installation

7. Following the DriverLINX prompts, turn off your computer and

install your DAS-1800AO board into an appropriate free slot in your
computer.

Setting the Base Address

The base address switch is preset at the factory for a hexadecimal value of
300 (768 decimal). If this address appears to conflict with the address of
another device in the computer (including other DAS-1800HC Series
boards), you must reset the base address switch.

The base address switch is a 7-position DIP switch located as shown in
Figure 3-1. To reset this switch for another address, use DriverLINX
software configuration (see "DriverLINX Configuration Notes" on page
C-1), to determine the new switch settings. The settings for the base
address switch must match the settings in the DriverLINX program.

Note:

The settings for the base address switch must match the settings
shown in DriverLINX.

Hex value when switch

is in down position:

200

80 20 8

100

40 10

Value of Hex 300

(768 decimal) shown

Figure 3-1. Location of Base Address Switch on DAS-1800AO Series

Boards

Installing the Software 3-5

Installing a Board

Caution:

your computer.

Use the following steps to install a DAS-1800AO Series board in an
accessory slot of your computer:

1. Turn off power to the computer and all attached equipment.

2. Remove the computer chassis cover.

3. Select an unoccupied accessory slot, and remove the corresponding

4. Make sure the settings of the base-address switch match the settings

5. Insert and secure the board in the selected slot.

6. Replace the computer cover.

You can use the DriverLINX Analog I/O Panel (see Section 5) to check
board operation.

Installing or removing a board while power is on can damage

cover plate from the I/O connector panel.

shown in the configuration-utility switch diagram.

Configuring the DAS-1800AO Board with DriverLINX

Note:

installations for Windows NT and Windows 95/98.

Be sure to make note of the configuration of all switches and jumpers on
the board. You will use this information to enter the correct configuration
parameters using DriverLINX. Also locate any information or notes about
the interrupt and DMA channels used by the other hardware devices in
your computer system.

3-6 Setup and Installation

Be sure to note and follow all programming differences between

Table 3-1 lists I/O addresses commonly used by IBM PC/XT, AT, and
compatible computers. Determine an even boundary of eight I/O
addresses within the range of 000H to 3F8H that are not being used by
another resource in your system (including another DAS-1800 Series
board), and set the switches to the appropriate base address.

Table 3-1. I/O Address Map (000H to 3FFH)

Address Range Use

000H to 00FH 8237 DMA #1

020H to 021H 8259 PIC #1

040H to 043H 8253 Timer

060H to 063H 8255 PPI (XT)

060H to 064H 8742 Controller (AT)

060H to 06FH 8042 Keyboard controller

070H to 071H CMOS RAM and NMI mask register (AT)

080H to 08FH DMA page registers

0A0H to 0A1H 8259 PIC #2 (AT)

0A0H to 0AFH NMI mask register (XT)

0C0H to 0DFH 8237 DMA #2 (AT - word-mapped)

0F0H to 0FFH 80287 Numeric processor (AT)

170H to 177H Hard disk controller #1

1F0H to 1F8H Hard disk controller #2

1F0H to 1FFH Hard disk controller (AT)

200H to 2FFH Game / control

210H to 21FH Expansion unit (XT)

238H to 23BH Bus mouse

23CH to 23FH Alternate bus mouse

278H to 27FH Parallel printer

2B0H to 2DFH EGA

2E0H to 2EFH GPIB (AT)

Configuring the DAS-1800AO Board with DriverLINX 3-7

Table 3-1. I/O Address Map (000H to 3FFH) (cont.)

Address Range Use

2E8H to 2EFH Serial port

2F8H to 2FFH Serial port

300H to 31FH Prototype card

320H to 32FH Hard disk (XT)

370H to 377H Floppy disk controller #2

378H to 37FH Parallel printer

380H to 38FH SDLC

3A0H to 3AFH SDLC

3B0H to 3BBH MDA

3BCH to 3BFH Parallel printer

3C0H to 3CFH VGA EGA

3D0H to 3DFH CGA

3E8H to 3EFH Serial port

3F0H to 3F7H Floppy disk controller #1

3F8H to 3FFH Serial port

The Expansion Board Configuration for Keithley DAS-1800 Series dialog
in DriverLINX allows you to record the settings of your analog input
multiplexers and enable the expansion channels. Make sure that the
switch settings match the settings you define in DriverLINX. Refer to the

DriverLINX Appendix F: Configuration and Implementation
Notes—Keithley DAS-1800 manual.

After you have successfully installed the DAS-1800AO Series board in
your computer, start Windows.

Run “Learn DriverLINX”

(LearnDL.exe)

from the DriverLINX program
group to tell DriverLINX how you configured your DAS-1800AO Series
board and to verify that everything is properly installed and configured.

3-8 Setup and Installation

1. Start Windows as you normally would and select the Program

Manager window.

2. Either select the “Learn DriverLINX” icon created when you

installed DriverLINX or enter “<drive>:/DRVLNX/LEARNDL” in
the

Command Line

by selecting the

edit box. The Command Line edit box is activated

Run...

option. <drive> is the letter of the hard disk

drive where DriverLINX is installed.

3. Immediately after loading Learn DL, the Open DriverLINX DLL

dialog box appears. Select the name of the hardware–specific DLL
from the list for your DAS-1800 Series board. The name is an
abbreviation of the board’s model number.

4. From the main menu bar of Learn DL

choose

Select....

,

select the

Device

menu and

5. Select the Logical Device you wish to configure and then click on the

OK

button.

6. Again select the

Device

menu and then choose the

Configure...

option

to display the Device Configuration Dialog Box.

Model

7. From the

list, select the model name for your DAS-1800

Series board you are configuring.

8. If the value displayed in the

Address

edit box is not correct, type the
correct value into the box. You can enter the address in decimal or
hexadecimal, using the c–notation for hex (that is, 768 decimal =
0x300 hexadecimal).

9. Choose the correct options for the

Counter/Timer Sections

by first clicking on the appropriate radio

Analog, Digital,

and

button in the middle of the dialog box and then completing the group
of dialog fields in the lower third of the dialog box. Be sure to click
on both the

Output

radio buttons for the

Analog

and

Digital

Input

and

groups to see all the dialog fields.

10. After you have made all your selections, save the configuration
parameters by clicking on the

OK

button. This will create or update

the configuration file, <device>.INI, in the Windows directory.

11. Repeat the preceding steps, starting at step 5, for each Logical Device
you wish to configure.

Configuring the DAS-1800AO Board with DriverLINX 3-9

You can use DriverLINX to verify board operation.

1. To physically initialize the DAS-1800AO, select

Device/Initialize

from the main menu in Learn DriverLINX.

2. The first time the DAS-1800AO is initialized or after a configuration
change, DriverLINX runs a diagnostic program to verify the
operation and accuracy of the configuration settings.

You are now ready to make I/O connections. Refer to Section 4 for
descriptions of common I/O accessories and connections for
DAS-1800AO Series Boards.

3-10 Setup and Installation

Cabling and Wiring

This section describes the cabling and wiring required for attaching
accessories and I/O lines to your DAS-1800AO Series boards.

4

Caution:

any attached accessories before making connections to DAS-1800AO
Series boards.

To avoid electrical damage, turn off power to the computer and

Attaching an STA-1800U

The STA-1800U screw terminal accessory is an interface for I/O
connections to DAS-1800AO Series boards; it contains the following
components:

Two 50-pin male connectors (J1 and J2). Use J1 for cabling to the

●

main I/O connector of a DAS-1800AO Series board; use J2 for
cabling to a second STA-1800U.

53 labeled screw terminals for connections from sensor outputs and

●

test equipment.

●

Four 26-pin male connectors for cabling to MB02 backplanes.
One 37-pin male connector for cabling to SSH-8 accessories or to an

●

MB01 backplane.

Attaching an STA-1800U 4-1

Figure 4-1 shows the connector layout of an STA-1800U accessory.

J10

J9

J1

J2

J3

J4

J5

J6

J11

J7

J8

Figure 4-1. Connector Layout of an STA-1800U Accessory

To attach an STA-1800U to a DAS-1800AO Series board, use a
CDAS-2000 Series cable. Connect the cable from the main I/O connector
of the DAS-1800AO Series board to connector J1 of the STA-1800U, as
shown in Figure 4-2.

DAS-1800AO Series Board

Cable

SDAS-2000

CDAS-2000 or

STA-1800U
Accessory

J1

Figure 4-2. Cabling and Connections f or Attaching an STA-1800U to

a DAS-1800AO Series Board

4-2 Cabling and Wiring

Pin assignments for main I/O connectors of DAS-1800AO Series boards
are shown in Figure 4-3.

(User Common Mode) U_CM MD - 01

CH00 LO or CH08 HI - 02
CH01 LO or CH09 HI - 03
CH02 LO or CH10 HI - 04
CH03 LO or CH11 HI - 05
CH04 LO or CH12 HI - 06
CH05 LO or CH13 HI - 07
CH06 LO or CH14 HI - 08
CH07 LO or CH15 HI - 09

— - 10
— - 11

+15V - 12

±15V Return - 13

D GND - 14

DI 1 - 15

DI 3 - 16
DO 1 - 17
DO 3 - 18

DOSTB - 19

TGOUT - 20
MUX 03 - 21
MUX 05 - 22
MUX 07 - 23

+5V - 24

D GND - 25

26 - CH00 HI
27 - CH01 HI
28 - CH02 HI
29 - CH03 HI
30 - CH04 HI
31 - CH05 HI
32 - CH06 HI
33 - CH07 HI
34 - LL GND
35 - ODAC0
36 - ODAC1
37 - −15V
38 - ±15V Return
39 - GEXT
40 - DI 0
41 - DI 2
42 - DO 0
43 - DO 2
44 - XPCLK
45 - SSHO
46 - TGIN
47 - MUX 04
48 - MUX 06
49 - +5V
50 - D GND

Figure 4-3. Pin Assignments for the Main I/O Connector of a

DAS-1800AO Series Board

Attaching an STA-1800U 4-3

Pin assignments for I/O connectors J1 and J2 of the STA-1800U are
shown in Figure 4-4.

(User Common Mode) U_CM MD - 01

CH00 LO or CH08 HI - 03
CH01 LO or CH09 HI - 05
CH02 LO or CH10 HI - 07
CH03 LO or CH11 HI - 09
CH04 LO or CH12 HI - 11
CH05 LO or CH13 HI - 13
CH06 LO or CH14 HI - 15
CH07 LO or CH15 HI - 17

— - 19
— - 21

+15V - 23

±15V Return - 25

D GND - 27

DI 1 - 29

DI 3 - 31
DO 1 - 33
DO 3 - 35

DOSTB - 37

TGOUT - 39
MUX 03 - 41
MUX 05 - 43
MUX 07 - 45

+5V - 47

D GND - 49

02 - CH00 HI
04 - CH01 HI
06 - CH02 HI
08 - CH03 HI
10 - CH04 HI
12 - CH05 HI
14 - CH06 HI
16 - CH07 HI
18 - LL GND
20 - —
22 - —
24 - −15V
26 - ±15V Return
28 - GEXT
30 - DI 0
32 - DI 2
34 - DO 0
36 - DO 2
38 - XPCLK
40 - SSHO
42 - TGIN
44 - MUX 04
46 - MUX 06
48 - +5V
50 - D GND

Figure 4-4. Pin Assignments for Main I/O Connectors J1 and J2 of

the STA-1800U

4-4 Cabling and Wiring

Attaching an STP-50

The STP-50 is a compact screw-terminal panel that you cable to the main
I/O connector of a DAS-1800AO Series board using a CDAS-2000 Series
cable, as shown in Figure 4-5. Pin assignments for the screw terminals of
this panel are shown in Figure 4-6.

DAS-1800AO Series Board

CDAS-2000 or

SDAS-2000

Cable

STP-50

Accessory

Figure 4-5. Attaching an STP-50 to a DAS-1800AO Series Board

(User-Common Mode) U_CM MD - 01

CH00 HI - 02

CH00 LO or CH08 HI - 03

CH01 HI - 04

CH01 LO or CH09 HI - 05

CH02 HI - 06

CH02 LO or CH10 HI - 07

CH03 HI - 08

CH03 LO or CH11 HI - 09

CH04 HI - 10

CH04 LO or CH12 HI - 11

CH05 HI - 12

CH05 LO or CH13 HI - 13

CH06 HI - 14

CH06 LO or CH14 HI - 15

CH07 HI - 16

CH07 LO or CH15 HI - 17

LL GND - 18

ODAC2 - 19
ODAC0 - 20
ODAC3 - 21
ODAC1 - 22

+15V - 23

−15V - 24

±15V Return - 25

26 - ±15 V Return
27 - D GND
28 - GEXT
29 - DI 1
30 - DI 0
31 - DI 3
32 - DI 2
33 - DO 1
34 - DO 0
35 - DO 3
36 - DO 2
37 - DOSTB
38 - XPCLK
39 - TGOUT
40 - SSHO
41 - MUX 03
42 - TGIN
43 - MUX 05
44 - MUX 04
45 - MUX 07
46 - MUX 06
47 - +5V
48 - +5V
49 - D GND
50 - D GND

Figure 4-6. Pin Assignments for Screw Terminals of the STP-50

Attaching an STP-50 4-5

Attaching an SSH-8

DAS-1800AO Series boards can accept one or two SSH-8 accessories.
The SSH-8 is a simultaneous sample-and-hold accessory whose functions
and capabilities are described in the
can serve as a front-end analog interface for DAS-1800AO Series boards
when connected through an STA-1800U. Note that attached SSH-8
accessories must be set as slaves. Attach an SSH-8 to an STA-1800U
using a C-1800 cable, as shown in Figure 4-7. Refer to the

Guide

for more information.

SSH-8
Accessory

DAS-1800AO Series Board

SSH-8 User’s Guide

J1
J3

C-1800 Cable

. This accessory

SSH-8 User’s

SDAS-2000

CDAS-2000 or

Cable

P1

STA-1800U Accessory

Figure 4-7. Cabling and Connections for Attaching an SSH-8 to a

DAS-1800AO Series Board

4-6 Cabling and Wiring

Attaching an MB01 Backplane

A DAS-1800AO Series board accepts one MB01 backplane through an
STA-1800U accessory. Cabling for attaching an MB01 backplane to an
STA-1800U accessory is shown in Figure 4-8.

DAS-1800AO Series Board

MB01

Accessory

MBX
X

Figure 4-8. Attaching an MB01 Backplane to a DAS-1800AO Series Board

MBX
X

CDAS-2000 or

SDAS-2000

Cable

#0#1#15

MBX
X

STA-1800U

C16-MB1 Cable

J1

J3

Attaching an MB01 Backplane 4-7

Attaching MB02 Backplanes

A DAS-1800AO Series board configured for single-ended inputs and
working through multiple STA-1800U accessories can support up to 16
MB02 backplanes. A single STA-1800U contains receptacles (J4 to J7)
for up to four MB02 backplane cables. Cabling for the four MB02
backplanes attached to an STA-1800U accessory is shown in Figure 4-9.

To J4 of the
STA-1800U

To J5 of the
STA-1800U

To J6 of the
STA-1800U

To J7 of the
STA-1800U

Figure 4-9. Cabling and Connections for Attaching MB02

C-2600
Cable

C-2600
Cable

C-2600
Cable

C-2600
Cable

#0 #1 #15

MBXXMB

XX

#0 #1 #15

MBXXMB

XX

#0 #1 #15

MBXXMB

XX

#0 #1 #15

MBXXMB

XX

Backplanes to an STA-1800U

MB02

MB
XX

MB02

MB
XX

MB02

MB
XX

MB02

MB
XX

Y ou can connect
up to four MB02

backplanes to

the STA-1800U

Use one STA-1800U for every four MB02 backplanes. Additional
STA-1800U accessories are daisy-chained to the first STA-1800U, using
CACC-2000 cables to connect J2 of one STA-1800U to J1 of the next, as
shown in Figure 4-10.

4-8 Cabling and Wiring

To Next

STA-1800U

Set for CH 7

Set for CH 6

Set for CH 5

Set for CH 4

T o Board 3 of MB02 Group 2

T o Board 4 of MB02 Group 2

DAS-1800AO Series Board

CACC-2000

Cables

STA-1800U

C-2600 Cables

T o Board 2 of MB02 Group 2

T

o Board 1of MB02 Group 2

Set for CH 1

Set for CH 3

Set for CH 2

Set for CH 0

J2

STA-1800U

T o Board 3 of MB02 Group 1

T o Board 2 of MB02 Group 1

T o Board 4 of MB02 Group 1

To Board 1of MB02 Group 1

CDAS-2000 or

SDAS-2000 Cable

J1

Figure 4-10. Daisy-Chaining STA-1800U Accessories with Attached MB02 Backplanes

The jumper pad beside each STA-1800U receptacle (J4 to J7) selects the
channel of the DAS-1800AO Series board that the attached MB02
backplane is to use. On the first STA-1800U, the jumpers connect
STA-1800U receptacles J4 to J7 to DAS-1800AO Series channels 0 to 3,
respectively (default settings), as shown in the diagram. On a second
STA-1800U, you position the jumpers to connect receptacles J4 to J7 to
channels 4 to 7, respectively; and so on. Refer to Figure B-4, in Appendix
B, for a diagram of receptacles J4 to J7 and their associated jumper pads.

For more information on MB Series backplanes and modules, refer to the

MB Series User’s Guide

Attaching MB02 Backplanes 4-9

.

Attaching EXP-1800 Accessories

An EXP-1800 accessory connects directly to the main I/O connector of a
DAS-1800AO Series board through a CDAS-2000 Series cable, as shown
in Figure 4-11. To connect an additional EXP-1800, connect a CAB-50/1
cable as shown in Figure 4-11.

DAS-1800AO Series Board

Cable

SDAS-2000

CDAS-2000 or

EXP-1800

CAB-50/1

Cable

EXP-1800

CAB-50/1

CACC-2000 Cable

Cable

J1

Figure 4-11. Daisy-Chaining EXP-1800 Accessories

You can attach up to 16 EXP-1800 accessories to a DAS-1800AO Series
board in this manner; however, some of the added EXP-1800s require
external power. For more information on the EXP-1800, refer to the

EXP-1800 User’s Guide

.

4-10 Cabling and Wiring

Connecting Signals

This section contains precautionary advice to consider before making I/O
connections. The section also shows some circuits for wiring signal
sources to input channels of DAS-1800AO Series boards.

The circuit diagrams represent a single signal source wired to a single
channel (channel
differential inputs or 16 separate signal sources to 16 single-ended inputs.

DAS-1800AO Series boards contain separate grounds for low-level
analog, ±15V power return, and digital signals. An analog ground
(LL GND) is for analog signals, a ±15V return is for analog power, and a
digital ground (D GND) is for digital signals and the +5V power-supply
return.

Precautions

If you expect to use a DAS-1801AO board at high gain, read the
precautionary information in the following subsection. Other
considerations for I/O connections are offered under “Additional
Precautions” on page 4-12.

n

). In reality, you can wire 8 separate signal sources to 8

Precautions for Using a DAS-1801AO Board at High Gains

Operating a DAS-1801AO board at gains of 50 or 250 can lead to
problems if your application is unable to cope with noise. At a gain of
250, each bit of A/D output corresponds to 10
with the high speed and bandwidth of this board, analog noise and
performance degradation come easily unless you take precautions to
avoid them. The following ideas and suggestions are aimed at avoiding
these problems:

Operate a DAS-1801AO board in 8-channel differential mode. Using

●

the board in 16-channel, single-ended mode at high gains introduces
enough ground-loop noise to produce large fluctuations in readings.

Minimize noise from crosstalk and induced-voltage pickup in the flat

●

cables and screw-terminal accessories by using shielded cable.
Connect the shield to LL GND and the inner conductors to Channel
LO and HI. Channel LO and LL GND should have a DC return (or

Connecting Signals 4-11

µ

V of analog input. Thus,

connection) at some point; this return should be as close to the signal
source as possible. Induced noise from RF and magnetic fields can
easily exceed tens of microvolts, even on one- or two-foot cables;
shielded cable eliminates this problem.

●

Avoid bi-metallic junctions in the input circuitry. For example, the
kovar leads, used on reed relays, typically have a thermal emf to
copper of 40
variations caused by air currents, and so on.

●

Consider filtering. This approach can use hardware (resistors,
capacitors, and so on), but is often accomplished more easily with
software. Instead of reading the channel once, read it 10 or more
times in quick succession and average the readings. If the noise is
random and gaussian, it will be reduced by the square-root of the
number of readings.

Additional Precautions

Do NOT mix your data acquisition inputs with the AC line or you risk
damaging the computer. Data acquisition systems give users access to
inputs of the computer. An inadvertent short between data and power lines
can cause extensive and costly damage to your computer. The
manufacturer can accept no liability for this type of accident. To prevent
this problem, use the following precautions:

µ

V/˚C. Thermals can introduce strange random

●

Avoid direct connections to the AC line.

●

Make sure all connections are tight and sound so that signal wires do
not come loose and short to high voltages.

●

Use isolation amplifiers where necessary.

4-12 Cabling and Wiring

Connecting a Signal to a Single-Ended Analog Input

Figure 4-12 shows the connections between a signal source and a channel
of a DAS-1800AO Series board configured for single-ended input mode.
For information on single-ended ground connections, refer to “Ground
Selection for Single-Ended Inputs” on page 2-4.

Signal

+

Source

-

Figure 4-12. Connections for Wiring a Signal Source to a DAS-1800AO Series Board

Note:

Channel n High

DAS-1800AO Series Board

LL GND

Configured for Single-Ended Inputs

When you wire signals to the analog input channels, you are
advised to wire all unused channels to LL GND. This action prevents the
input amplifiers from saturating and ensures the accuracy of your data.

Connecting a Signal to a Differential Analog Input

This section describes common connection schemes for differential
inputs and discusses the principles for avoiding ground loops.

Common Connection Schemes for Differential Inputs

Figure 4-13 shows three connection schemes for wiring a signal source to
a channel of a DAS-1800AO Series board configured for differential input
mode.

The upper two circuits of the diagram require the addition of resistors to
provide a bias-current return. You can determine the value of the bias
return resistors (R

) from the value of the source resistance (Rs), using the

b

following relationships:

When Rs is greater than 100Ω, use the connections in the upper

●

circuit. The resistance of each of the two bias return resistors must
equal 2000 R

Connecting Signals 4-13

.

s

When Rs is less than 100Ω, use the connections in the middle circuit.

●

The resistance of the bias return resistor must be greater than 1000
R

.

s

In the lower circuit of Figure 4-13, bias current return is inherently
provided by the source. The circuit requires no bias resistors. R
signal source resistance while R

is the resistance required to balance the

v

is the

s

bridge.

Signal

R

Source

Where Rs > 100Ω
Rb = 2000 R

Signal

Source

Where Rs < 100Ω

= 1000 R

R

b

+

DC

Supply

s

s

R

s

s

Bridge

R

v

R

s

+

R

-

+

R

-

-

b

b

Channel n High

Channel n Low

R

b

LL GND

Channel n High

Channel n Low

LL GND

Channel n High

Channel n Low

LL GND

DAS-1800AO Series Board

DAS-1800AO Series Board

DAS-1800AO Series Board

Figure 4-13. Three Types of Connections for Wiring a Signal Source to a DAS-1800AO

Series Board Configured for Differential Inputs

4-14 Cabling and Wiring

Avoiding Ground Loops with Differential Inputs

Very often, the signal-source ground and the DAS-1800AO Series board
ground are not at the same voltage level because of the distances between
equipment wiring and the building wiring. This difference is referred to as
a

common-mode voltage

sides of a differential input (it appears between each side and ground).
Since a differential input responds only to the difference in the signals at
its high and low inputs, its common-mode voltages cancel out and leave
only the signal. However, if your input connections contain a ground
loop, your input could see the sum of the signal-source and common­mode voltages. Figure 4-14 shows the proper way to connect a differential
input. Figure 4-15 illustrates the effect of a ground loop.

(Vcm) because it is normally common to both

Signal

Source

Signal Source

Ground V

+

E

s

-

g 1

Channel n High

Channel n Low

V

c m

R

wire

V

= V

g 1

- V

c m

LL GND

V

g 2

g 2

E

s

DAS-1800AO Series Board

Do not join Low

to LL GND at the

computer

Figure 4-14. A Differential Input Configuration that Avoids a Ground Loop

Signal

Source

Signal Source

Ground V

+

E

s

-

g 1

Channel n High

Channel n Low

V

c m

R

wire

V

= V

c m

g 1

- V

Es + V

LL GND

V

g 2

g 2

c m

DAS-1800AO Series Board

This diagram is included

only to illustrate an
incorrectly wired input; do
not use this configuration.

NOTE

Figure 4-15. Differential Input Configuration with a Ground Loop

Connecting Signals 4-15

Connecting Analog Output Signals

Outputs for DAC 0 and DAC 1 are assigned to main I/O connector pins 35
and 36, respectively. These outputs are available on screw terminals of the
STP-50 (see “Attaching an STP-50” on page 4-5) and on appropriately
labeled screw terminals of the STA-1800U. Also on the STA-1800U,
DAC 0 is present on pin 3 of connector J4 and DAC 1 is present on pin 3
of connector J5. Refer to Figure B-4 in Appendix B. The presence of these
outputs on connectors J4 and J5 of the STA-1800U makes the outputs
available to any MB02 backplanes attached to those connectors.

Connecting Digital I/O Signals

DAS-1800AO Series boards have four digital inputs and four digital
outputs, as described in “Digital I/O Features” on page 2-24. Make your
connections to the digital I/O terminals through corresponding terminals
of the STA-1800U. The terminals are labeled as follows:

● Digital input — The digital input terminals are DI 0 to DI 3.

● Digital output — The digital output terminals are DO 0 to DO 3.

Connecting Digital Control Signals

DAS-1800AO Series boards use five digital control signals. Make your
connections to the digital control terminals through corresponding
terminals of the STA-1800U. The terminals are labeled as follows:

● SSHO — The simultaneous sample-and-hold output terminal. This

signal is described in “Using Digital Control Signal SSHO” on page
2-26. Use the SSHO terminal for connecting this signal.

● TGIN — The trigger/gate input, described in the next section and in

“Using Digital Control Signals TGOUT and TGIN” on page 2-25.
Also, refer to “Triggers” on page 2-14 and to “Gates” on page 2-17.
Use the trigger/gate TGIN for connecting a TGIN signal.

● TGOUT — The trigger/gate output, described in the next section and

in “Using Digital Control Signals TGOUT and TGIN” on page 2-25.
Use the TGOUT terminal for connecting this signal.

4-16 Cabling and Wiring

● XPCLK — The external pacer clock input, described in the next

section and in “Clock Sources” on page 2-12. Use the external clock
terminal XPCLK for connecting this signal.

● DOSTB — The digital output strobe, described in “Using Digital

Control Signal DOSTB” on page 2-24. Use the DOSTB terminal for
connecting this signal.

Connecting and Synchronizing Multiple Boards

You can synchronize up to three DAS-1800 Series boards using trigger
and gate signals from the main I/O connectors. Each board can run at the
same or different conversion rate as the other boards in the system.

The onboard pacer clock is designed to be tightly coupled with trigger
and gate operations. After each board receives the trigger or gate,
conversions begin within a defined period of time. If each board is
programmed for a different conversion rate, the first conversion on each
board occurs after this time period and subsequent conversions occur at
the programmed rate.

Figure 4-16 shows two connection schemes for synchronizing multiple
boards. Both schemes are using the onboard pacer clock to time
acquisitions.

Board 0
Rate a

Board 1
Rate b

Board 2
Rate c

a. Scheme 1

TGIN

TGIN

TGIN

Trigger or
Gate

Board 0
Rate a

Board 1
Rate b

Board 2
Rate c

TGIN

TGOUT

TGIN

TGIN

b. Scheme 2

Trigger or
Gate
(optional)

Figure 4-16. Two Connection Schemes for Synchronizing Multiple Boards

Connecting Signals 4-17

In Scheme 1, you connect the trigger/gate inputs of the three boards
together and supply the trigger or gate input. A/D conversions on each
board start 400 ±100ns from the active edge of the trigger input. All
conversions start within 100 ±100ns of each other from board to board.
When using scheme 1, you can use the onboard pacer clock or an external
pacer clock.

In Scheme 2, you can start conversions in either of two ways: by a
hardware trigger/gate input or by software. The board connections are in a
master/slave relationship. Board 0 is the master and boards 1 and 2 are the
slaves.

If you use a software enable for board 0 of scheme 2, the board 0 pacer
clock starts and triggers conversions in the slave boards. However, board
0 conversions do not begin until after conversions begin in the the slave
boards. The delay of board 0 conversions is caused by a protection feature
built into the register that creates software-triggered conversions. The
function of the protection feature is to prevent false conversions.

If you use a hardware trigger for board 0 of scheme 2, board 0 triggers
conversions in all three boards immediately. Note that TGOUT is an
active, high-going signal. Therefore, you must program the slave-board
TGIN inputs for a positive-going trigger or gate.

4-18 Cabling and Wiring

Testing the Board

This section describes how to use DriverLINX to test functions of
DAS-1800AO Series boards.

DriverLINX Analog I/O Panel

The DriverLINX Analog I/O Panel is an application that demonstrates
analog input/output using DriverLINX. With the Analog I/O Panel you
can:

Analyze analog signals using the two-channel Oscilloscope.

●

●

Measure analog voltages using the Digital Volt Meter.

●

Generate Sine, Square, and Triangle waves using the SST Signal
Generator.

5

●

Output DC Level voltages using the Level Control.

The Analog I/O Panel is useful for:

Testing the DAS-1800AO DriverLINX installation and configuration.

●

●

Verifying signal inputs to your DAS-1800AO board.

●

Sending test signals to external devices.

To access this DriverLINX Analog I/O Panel:

1. Start the Analog I/O Panel with the “AIO Panel” item on the Windows
start menu. Then perform the following steps.

2. Click the [...] button in the Driver Selection section.

3. Select the driver for your board using the

4. Click

DriverLINX Analog I/O Panel 5-1

OK.

Open DriverLINX

dialog.

5. Select the Logical Device you want to operate by dragging the pointer
in the Device Selection section. The Analog I/O Panel displays the
Scope, Meter, SST, and Level control tabs, depending on the
capabilities of your DAS-1800AO board.

6. The Scope uses two analog input channels, referred to as ChA and
ChB. Drag the channel selectors in the AI Channel Mapping section
to map them to different channel numbers.

7. The SST Signal Generator uses two analog output channels, referred
to as ChA and ChB. Drag the channel selectors in the AO Channel
Mapping section to map them to different channel numbers.

You can now select the Scope, Meter, SST, and Level Control tabs to
operate your DAS-1800AO board.

Test Panel Application

Depending upon the DriverLINX drivers you have installed on your
system, you will have one or more of the following example applications:

●

Single–Value AI

for analog input

Single–Value AO

●

●

PIO Panel

●

CTM Test Bench

for analog output

for digital input and output

for counter/timer applications.

To access this DriverLINX Test Panel, select Test Panel with the “Test
Panel” item on the Windows start menu.

5-2 Testing the Board

Your DAS-1800AO Series board is initially calibrated at the factory. You
are advised to check the calibration of a board every six months and to
calibrate again when necessary. This section provides the information you
need to calibrate a DAS-1800AO Series board.

Equipment Requirements

The equipment requirements for calibrating a DAS-1800AO Series board
are as follows:

●

A digital voltmeter accurate to 6½ digits, such as a Keithley
Instruments Model 196 or 2001.

6

Calibration

An adjustable ±10V voltage calibrator, such as a Keithley

●

Instruments Model 236.

●

An STA-1800U or an STP-50 accessory and a CDAS-2000 cable; or a
user-designed interface.

●

The appropriate number of CDAS-2000 cables for EXP-1800
accessories, if used.

Potentiometers and Test Points

Figure 6-1 shows the locations of the potentiometers and test points
involved with the calibration of a DAS-1800AO Series board. In the
diagram, the term RTI is
described in the next section, directs you to these components and
explains what to do with them during the calibration process.

Equipment Requirements 6-1

Referred to Input

. The calibration utility,

DAC 0
Gain

DAC 0
Offset

DAC 1
Gain

DAC 1
Offset

A/D
Bipolar
Offset

A/D
Gain

VOUT

Unipolar
Offset

AGND

RTI Offset

R42 R44R43 R46

TP6

DAC 0 Out

DGND,

ADCSTB, and

ADCSTAT

TP7

DAC 1 Out

TP5

TP3

TP1

TP4

Figure 6-1. Potentiometers and Test Points on the

DAS-1800AO Series Boards

DriverLINX Calibration Utility

DriverLINX Calibration Utility will guide you through the calibration
procedure. Before calibration, specify the following parameters in the
setup panel to get the correct instructions:

TP2 R41R40R38R45

Logical Device —

●

●

Accessory

— Connection method used to connect the board to the

Board’s device number, model, and address.

calibration stimulus.

Shorted Channel —

●

●

Voltage Channel —

Input channel to be “shorted” high to low.

Input channel to use to apply the various

calibration voltage levels.

Calibration Range —

●

6-2 Calibration

Input range to be calibrated.

If your DAS-1800AO Series board is not operating properly, use the
information in this chapter to isolate the problem. If the problem appears
serious enough to warrant technical support, refer to “Technical Support”
on page 7-6 for information on how to contact an applications engineer.

Problem Isolation

If you encounter a problem with a DAS-1800AO Series board, use the
instructions in this section to isolate the cause of the problem before
calling Keithley for technical support.

7

Troubleshooting

Using the DriverLINX Event Viewer

The DriverLINX Event Viewer displays the Windows system event log.
Applications and hardware drivers make entries in the system event log to
assist in predicting and troubleshooting hardware and software problems.

DriverLINX uses the event log to report problems during driver loading
or unexpected system errors. The event log can assist in troubleshooting
resource conflicts and DriverLINX configuration errors. If you are having
trouble configuring or initializing a Logical Device, check the event log
for information from the DriverLINX driver.

Using the DriverLINX Event Viewer, you can view DriverLINX event log
entries under Windows 95/98 or Windows NT. DriverLINX event log
entries can help you or technical support troubleshoot data-acquisition
hardware and software problems.

Problem Isolation 7-1

Device Initialization Error Messages

During device initialization, DriverLINX performs a thorough test of all
possible subsystems on the DAS-1800AO Series board as well as the
computer interface. If DriverLINX detects any problems or unexpected
responses, it reports an error message to help isolate the problem. The
device initialization error messages fall into three basic categories:

“Device not found” —

●

Board address does not match hardware
setting or conflicts with another board. Verify the board’s address
settings. Also, do not confuse hexadecimal with decimal addresses in
the DriverLINX

●

“Invalid IRQ level”

Device Configure

or

“Invalid DMA level” —

dialog box.

not match hardware setting, conflicts with another board’s IRQ/DMA
levels, or is dedicated to the computer’s internal functions (COM
port, disk drive controller, network adapter, etc.).

●

“Hardware does not match configuration” —

mode/range switch or jumper setting does not match selection(s)
made in the DriverLINX

Device Configuration

Identifying Symptoms and Possible Causes

Use the troubleshooting information in Table 7-1 to isolate the problem.
Table 7-1 lists general symptoms and possible solutions for problems with
DAS-1800AO Series boards.

Selected level does

Operating

dialog box.

7-2 Troubleshooting

Table 7-1. Troubleshooting Information

Symptom Possible Cause Possible Solution

Board does not
respond

Intermittent
operation

Base address is incorrect or not
consistent with what the program
is addressing.

The interrupt level or DMA is
incorrect or not consistent with
what the program is addressing.

The board configuration is
incorrect.

The board is incorrectly aligned
in the accessory slot.

The board is damaged. Contact the Keithley Hardware

The most common cause of this
problem is that the I/O bus speed
is in excess of 8MHz.

Check the base-address-switch setting
on the board against the setting shown in
the configuration utility. If the base
address is set correctly, make sure no
other computer device is using any of
the I/O locations beginning at the
specified base address. If necessary,
reconfigure the base address. Refer to
page 3-5 for instructions on setting the
base address.

Make sure no other computer device is
using the interrupt level or DMA
specified in your program. If necessary,
reset the interrupt level.

Check the remaining settings in the
configuration file.

Check the board for proper seating.

Applications Engineering Department;
see page 7-6.

Reduce I/O bus speed to a maximum of
8MHz (to change the I/O bus speed, run
BIOS setup). See your computer
documentation for instructions on
running BIOS setup.

Vibrations or loose connections
exist.

The board is overheating. Check environmental and ambient

Electrical noise exists. Provide better shielding or reroute

Problem Isolation 7-3

Cushion source of vibration and tighten
connections.

temperature. See the documentation for
your computer.

unshielded wiring.

Table 7-1. Troubleshooting Information (cont.)

Symptom Possible Cause Possible Solution

Data appears to be
invalid

Computer does not
boot

The most common cause of this
problem is that the I/O bus speed
is in excess of 8MHz.

An open connection exists. Check wiring to screw terminal.

Another system resource is using
the specified base address.

Transducer is connected to
channel being read.

Board is set for single-ended
mode, while transducer is a
differential type or vice versa.

Board not seated properly. Check the installation of the board.

The base address setting of the

DAS-1800AO Series

conflicts with that of another
system resource.

board

Reduce I/O bus speed to a maximum of
8MHz (to change the I/O bus speed, run
BIOS setup). See the documentation for
your computer for instructions on
running BIOS setup.

Reconfigure the base address of the
DAS-1800AO Series board; refer to
Section 3 for more information. Check
the I/O assignments of other system
resources and reconfigure, if necessary.

Check the transducer connections.

Check transducer specifications and
board configuration.

Check the base address settings of your
system resources; each address must be
unique.

The power supply of the host
computer is too small to handle
all the system resources.

System lockup A timing error occurred. Press

Check the needs of all system resources
and obtain a larger power supply.

[Ctrl] + [Break]

.

If your board is not operating properly after using the information in
Table 7-1, continue with the next two sections to further isolate the
problem.

7-4 Troubleshooting

Testing the Board and Host Computer

To isolate the problem to the DAS-1800AO Series board or to the host
computer, use the following steps:

1. Turn the power to the host computer OFF and remove power
connections to the computer.

Caution:

your board and/or computer.

2. While keeping connections to accessory board intact, unplug the
accessory connector or cable from the DAS-1800AO Series board.

3. Remove the DAS-1800AO Series board from the computer and
visually check for damage. If a board is obviously damaged, refer to
“Technical Support” on page 7-6 for information on returning the
board.

4. With the DAS-1800AO Series board out of the computer, check the
computer for proper operation. Power up the computer and perform
any necessary diagnostics.

At this point, if you have another DAS-1800AO Series board that you
know is functional, you can test the slot and I/O connections using the
instructions in the next section. If you do not have another board, refer to
the instructions on page 7-6 before calling Keithley Technical Support.

Removing a board with the power ON can cause damage to

Testing the Accessory Slot and I/O Connections

When you are sure that the computer is operating properly, test the
computer accessory slot and I/O connections using another DAS-1800AO
Series board that you know is functional. To test the computer accessory
slot and the I/O connections, follow these steps:

1. Turn computer power OFF and install a functional DAS-1800AO
Series board. Do not make any I/O connections.

2. Turn computer power ON and check operation with the functional
board in place. This test checks the computer accessory slot. If you
were using more than one DAS-1800AO Series board when the
problem occurred, use the functional board to test the other slot.

Problem Isolation 7-5

3. If the accessory slots are functional, use the functional board to check
the I/O connections. Reconnect and check the operation of the I/O
connections, one at a time.

4. If operation fails for an I/O connection, check the individual inputs
one at a time for shorts and opens.

5. If operation remains normal to this point, the problem is in the
DAS-1800AO Series board(s) originally in the computer. If you were
using more than one board, try each board one at a time in the
computer to determine which is faulty.

6. If you cannot isolate the problem, refer to the next section for
instructions on obtaining assistance.

Technical Support

Before returning any equipment for repair, call Keithley for technical
support at:

1-888-KEITHLEY
Monday - Friday, 8:00 a.m. - 5:00 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 following
information available before you call:

7-6 Troubleshooting

DAS-1800AO Series
Board Configuration

Computer

Operating System

Software package

Model
Serial #
Revision code
Base address setting
Interrupt level setting
Number of channels
Input (S.E. or Diff.)
Mode (uni. or bip.)
DMA chan(s)
Number of SSH-8s
Number of EXPs.

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

DOS version
Windows version
Windows mode

Name
Serial #
Version
Invoice/Order #

___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________

___________________
___________________
___________________
___________________
___________________
___________________

___________________
___________________
___________________

___________________
___________________
___________________
___________________

Compiler
(if applicable)

Accessories

Technical Support 7-7

Language
Manufacturer
Version

Type
Type
Type
Type
Type
Type
Type
Type

___________________
___________________
___________________

___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________

If a telephone resolution is not possible, the applications engineer will
issue you a Return Material Authorization (RMA) number and ask you to
return the equipment. Include the RMA number with any documentation
regarding the equipment.

When returning equipment for repair, include the following information:

●

Your name, address, and telephone number.
The invoice or order number and date of equipment purchase.

●

●

A description of the problem or its symptoms.

●

The RMA number on the

outside

of the package.

Repackage the equipment, using the original anti-static wrapping, if
possible, and handle it with ground protection. Ship the equipment to:

ATTN.: RMA# _______
Repair Department
Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139-1891

Telephone 1-888-KEITHLEY
FAX [phone]

Note:

If you are submitting your equipment for repair under warranty,

you must include the invoice number and date of purchase.

To enable Keithley to respond as quickly as possible, you must include
the RMA number on the outside of the package.

7-8 Troubleshooting

Specifications

Tables A-1 to A-4 list specifications for the DAS-1800AO Series boards.

Table A-1. Analog Input Specifications

Feature DAS-1801AO DAS-1802AO

Number of channels Software-selectable as 8 differential or 16 single-ended

Input mode Software-selectable as unipolar or bipolar

Resolution 12-bit (1 part in 4096)

Data format 16-bit 2’s complement

FIFO size 1024 word

A

Gain (range) • 1 (0.0 to +5.0V for unipolar)

• 1 (±5.0V for bipolar)

• 5 (0.0 to +1.0V for unipolar)

• 5 (±1.0V for bipolar)

• 50 (0 to 100mV for unipolar)

• 50 (±100mV for bipolar)

• 250 (0 to +20mV for unipolar)

• 250 (±20mV for bipolar)

Absolute accuracy Typical:

0.01% of reading ±1 LSB for all ranges

Maximum error:

• 0.02% of reading ±1 LSB max @ 25˚C for gain < 250

• 0.03% of reading ±1 LSB max @ 25˚C for gain = 250

• 1 (0.0 to +10V for unipolar)

• 1 (±10V for bipolar)

• 2 (0.0 to +5.0V for unipolar)

• 2 (±5.0V for bipolar)

• 4 (0.0 to +2.5V for unipolar)

• 4 (±2.5V for bipolar)

• 8 (0.0 to 1.25V for unipolar)

• 8 (±1.25V for bipolar)

A-1

Table A-1. Analog Input Specifications (cont.)

Feature DAS-1801AO DAS-1802AO

Temperature coefficient of
accuracy (includes ADC)

Offset:

• ±20µV/˚C ±(12µV/˚C ÷ gain) maximum for bipolar

• ±20µV/˚C ±(14µV/˚C ÷ gain) maximum for unipolar

Gain:

• ±20ppm/˚C for gain < 50

• ±30ppm/˚C for gain = 50

• ±35ppm/˚C for gain = 250

Linearity

1

• Integral: ±½ LSB typical, ±1 LSB maximum

• Differential: ±1 LSB

Throughput Refer to “Maximum A/D Throughput Rates” on page 2-7

Dynamic parameters • Acquisition time: 0.3µs

• Aperture delay: 13.0ns

• Aperture uncertainty: 150ps rms

• Conversion time: 3.0µs max. (includes acquisition time)

Input bias current • ±40nA max. @ 25˚C

• ±60nA maximum over operating range

Common-mode rejection
ratio

• 74 dB for gain = 1

• 80 dB for gain = 5

• 100 dB for gain = 50

• 100 dB for gain = 250

• 74 dB for gain = 1

• 80 dB for gain = 2

• 80 dB for gain = 4

• 86 dB for gain = 8

Input overvoltage • ±15V continuous powered

• ±15V continuous unpowered

Noise

2

Bipolar electrical noise (in
counts)

• p-p = 1, rms = 0.1 for gain = 1

• p-p = 1, rms = 0.1 for gain = 5

• p-p = 2, rms = 0.2 for gain = 50

• p-p = 3, rms = 0.5 for gain = 250

Unipolar electrical noise (in
counts):

• p-p = 1, rms = 0.1 for gain = 1

• p-p = 1, rms = 0.1 for gain = 5

• p-p = 3, rms = 0.4 for gain = 50

• p-p = 5, rms = 0.9 for gain = 250

Bipolar electrical noise (in
counts)

• p-p = 1, rms = 0.1 for gain = 1

• p-p = 1, rms = 0.1 for gain = 2

• p-p = 1, rms = 0.1 for gain = 4

• p-p = 1, rms = 0.1 for gain = 8

Unipolar electrical noise (in
counts):

• p-p = 1, rms = 0.1 for gain = 1

• p-p = 1, rms = 0.1 for gain = 2

• p-p = 1, rms = 0.1 for gain = 4

• p-p = 1, rms = 0.1 for gain = 8

A-2 Specifications

Table A-1. Analog Input Specifications (cont.)

Feature DAS-1801AO DAS-1802AO

DMA • Burst demand mode DMA

• Request on FIFO Not Empty

• Programmable levels (levels 5, 6, and 7)

• Single/dual DMA modes

Interrupt • On FIFO Not Empty

• On FIFO Half Full

• On A/D Counter 0 Terminal Count

• On Data Overflow

• Programmable interrupt levels (levels 3, 5, 7, 10, 11, and 15)

Channel QRAM 256 x 8 bits (256 channels maximum)

Gain QRAM 256 x 3 bits (4 onboard gain ranges; 2 external)

Trigger sources
(all with programmable
polarity)

• Internal clock, internal gate

• Internal clock, external trigger

• Internal clock, external gate

• External clock, internal gate

• External clock, external trigger

• External clock, external gate

Trigger types • Pre-trigger

• About-trigger (using A/D counter 0)

• Post-trigger

Burst mode acquisition
control

• Rate: programmable 16 ksamples/s to 333 ksamples/s

• Length: programmable 1 to 256 conversions

• Other: simultaneous sample-and-hold support

Sample clock • Internal: 32-bit counter (82C54)

• External: programmable edge polarity

Minimum external pacer

10ns

clock pulse width

Maximum external pacer

333kHz

clock rate

Minimum hardware trigger

10ns

pulse width

1

Monotonicity is guaranteed over the operating range.

2

The figures in the table show the electrical noise introduced by the analog front end

uncertainty inherent in the quantization process

to uncertainty at code boundaries and adds a peak-to-peak value of 1 LSB to the electrical noise; it also makes the
rms level 0.5 LSBs.

. The inherent quantization noise introduced by any ADC is due

but do not include the

A-3

Table A-2. Analog Output Specifications

Feature DAS-1800AO Series Boards

Channels 2, deglitched

Range ±5V, ±10V (software selectable for each DAC)

Resolution 12-bit (1 part in 4096 or 244 ppm)

Current output ±15mA maximum

Output impedance 4Ω (maximum @ 300kHz)

Capacitive drive 100µF maximum

Glitch energy Zero glitch feedthrough

Hold error 1.5nV * s , typical ( i.e. 1mV * 1.5µs); 7.5nV * s, maximum

Gain accuracy Adjustable to 0

Offset accuracy Adjustable to 0

Linearity • Integral: ±0.25 LSB typical; ±0.75 LSB maximum

• Differential: ±0.75 LSB maximum

• Monotonicity: guaranteed over operating range

Settling time • 3µs for 20V step, typical

• 1.8µs for LSB of major carry, typical

Slew rate 10V/µs minimum

Throughput 500 ksamples/s maximum for each DAC using recycle mode and with

small voltage steps

Output at reset or power-up 0V

Data transfer size 16 bits (AT bus)

FIFO 2048 word

Format 12-bit, 2’s complement, right-justified

DMA • Burst demand mode DMA

• Programmable DMA levels (levels 5, 6, and 7)

• Request on FIFO Not Full

Interrupt • On FIFO not full

• On FIFO not half full

• On data underflow

• On DMA terminal count

• Uses selected A/D interrupt level

A-4 Specifications

Table A-2. Analog Output Specifications (cont.)

Feature DAS-1800AO Series Boards

Trigger source
(with programmable
polarity)

• Internal clock, internal gate

• Internal clock, external trigger

• Internal clock, external gate

• External clock, internal gate

• External clock, external trigger

• External clock, external gate

Sample clock • Internal: 16-bit counter using 5MHz clock (with selectable

divide-by-10 prescaler) or using pacer clock

• External: Programmable edge polarity

Table A-3. Digital I/O Specifications

Feature DAS-1800AO Series Boards

Digital output signals
DOSTB, SSHO, and
TGOUT

Digital output signals DO 0
to DO 3, GEXT, and MUX 3
to MUX 7

Digital input signals DI 0 to
DI 3, XPCLK, and TGIN

• VOH (min.) = 2.4V @ IOH = −3mA

• VOL (max.) = 0.5V @ IOL = 24mA

• VOH (min.) = 2.7V @ IOH = −0.4mA

• VOL (max.) = 0.5V @ IOL = 8mA

• VIH (min.) = 2.0V; IIH (max.) = 0.02mA

1

• VIL (max.) = 0.8V; IIL (max.) = −0.2mA

Digital output strobe pulse

300ns typical; data is latched on the rising edge of DOSTB

width

1

Digital inputs DI 0 to DI 3 are pulled up with 10kΩ resistors; inputs TGIN and XPCLK are not pulled up.

A-5

Table A-4. Power Supply Requirements

Attribute DAS-1800AO Series Boards

+5VDC input 510mA typical; 835mA maximum

+12VDC input 455mA typical; 690mA maximum

Maximum current available
at the ±15V outputs

Maximum current available
at the +5V output

30mA

1A

A-6 Specifications

Connector Pin Assignments

This appendix contains pin assignments for connectors of the
DAS-1800AO Series boards and the STA-1800U accessory.

Main I/O Connector of DAS-1800AO Series Boards

Figure B-1 shows pin assignments for main I/O connectors of
DAS-1800AO Series boards.

B

D GND - 25

+5V - 24
MUX 07 - 23
MUX 05 - 22
MUX 03 - 21

TGOUT - 20
DOSTB - 19

DO 3 - 18
DO 1 - 17

DI 3 - 16

DI 1 - 15

D GND - 14

±15V Return - 13

+15V - 12

— - 11

— - 10
CH07 LO or CH15 HI - 09
CH06 LO or CH14 HI - 08
CH05 LO or CH13 HI - 07
CH04 LO or CH12 HI - 06
CH03 LO or CH11 HI - 05
CH02 LO or CH10 HI - 04
CH01 LO or CH09 HI - 03
CH00 LO or CH08 HI - 02

(User Common Mode) U_CM MD - 01

50 - D GND
49 - +5V
48 - MUX 06
47 - MUX 04
46 - TGIN
45 - SSHO
44 - XPCLK
43 - DO 2
42 - DO 0
41 - DI 2
40 - DI 0
39 - GEXT
38 - ±15V Return
37 - −15V
36 - ODAC1
35 - ODAC0
34 - LL GND
33 - CH07 HI
32 - CH06 HI
31 - CH05 HI
30 - CH04 HI
29 - CH03 HI
28 - CH02 HI
27 - CH01 HI
26 - CH00 HI

Figure B-1. Pin Assignments for the Main I/O Connector of a

DAS-1800AO Series Board

Main I/O Connector of DAS-1800AO Series Boards B-1

I/O Connectors J1 and J2 of the STA-1800U Accessory

Figure B-2 shows pin assignments for I/O connectors J1 and J2 of the
STA-1800U accessory.

(User Common Mode) U_CM MD - 01

CH00 LO or CH08 HI - 03
CH01 LO or CH09 HI - 05
CH02 LO or CH10 HI - 07
CH03 LO or CH11 HI - 09
CH04 LO or CH12 HI - 11
CH05 LO or CH13 HI - 13
CH06 LO or CH14 HI - 15
CH07 LO or CH15 HI - 17

— - 19
— - 21

+15V - 23

±15V Return - 25

D GND - 27

DI 1 - 29

DI 3 - 31
DO 1 - 33
DO 3 - 35

DOSTB - 37

TGOUT - 39
MUX 03 - 41
MUX 05 - 43
MUX 07 - 45

+5V - 47

D GND - 49

02 - CH00 HI
04 - CH01 HI
06 - CH02 HI
08 - CH03 HI
10 - CH04 HI
12 - CH05 HI
14 - CH06 HI
16 - CH07 HI
18 - LL GND
20 - ODAC0
22 - ODAC1
24 - −15V
26 - ±15V Return
28 - GEXT
30 - DI 0
32 - DI 2
34 - DO 0
36 - DO 2
38 - XPCLK
40 - SSHO
42 - TGIN
44 - MUX 04
46 - MUX 06
48 - +5V
50 - D GND

Figure B-2. Pin Assignments for Main I/O Connectors J1 and J2 of

the STA-1800U Accessory

B-2 Connector Pin Assignments

Connector J3 of the STA-1800U Accessory

Connector J3 of the STA-1800U screw terminal accessory is a 37-pin
male D connector that accepts a C-1800 cable from an SSH-8 accessory
or a C16-MB1 cable for an MB01 backplane. Pin assignments for J3 are
shown in Figure B-3.

- +5V

SSHO -

— ­DO 2 ­DO 0 -

DI 2 ­DI 0 -

— -

— -

LL GND -

LL GND ­CH07 HI ­CH06 HI ­CH05 HI ­CH04 HI ­CH03 HI ­CH02 HI ­CH01 HI ­CH00 HI -

20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

1

- TGOUT

2

- DO 3

3

- DO 1

4

- DI 3

5

- DI 1

6

- D GND

7

- —

8

- —

9

- —

10

- CH07 LO or CH15 HI

11

- CH06 LO or CH14 HI

12

- CH05 LO or CH13 HI

13

- CH04 LO or CH12 HI

14

- CH03 LO or CH11 HI

15

- CH02 LO or CH10 HI

16

- CH01 LO or CH09 HI

17

- CH00 LO or CH08 HI

18

- LL GND

19

Figure B-3. Pin Assignments for STA-1800U Connector J3

Connectors J4 to J7 and Jumper Pads J8 to J11 of the STA-1800U Accessory

Connectors J4 to J7 of the STA-1800U accessory are 26-pin male
connectors that each accept a C-2600 cable from an MB02 backplane.
Figure B-4 shows the pin assignments for J4 to J7.

Connector J3 of the STA-1800U Accessory B-3

.

CH04 LO/CH12 HI
CH00 LO/CH08 HI
CH04 HI
CH00 HI

CH05 LO/CH13 HI
CH01 LO/CH09 HI
CH05 HI
CH01 HI

1

2

3

11
13
15
17
19
21
23
25

11
13
15
17
19
21
23
25

4

5

6

7

8

9

10
12
14
16
18
20
22
24
26

CH06 LO/CH14 HI
CH02 LO/CH10 HI
CH06 HI
CH02 HI

1

2

3

4

5

6

7

8

9

10
12
14
16
18
20
22
24
26

ODAC 0
LL GND
MUX 04
MUX 06 MUX 07

D GND D GND

Connector J4 and

Jumper Pad J8

ODAC 2

LL GND

MUX04
MUX06 MUX07

D GND D GND

Connector J6 and

Jumper Pad J10

LL GND

MUX 05

LL GND

MUX05

1

2

3

11
13
15
17
19
21
23
25

11
13
15
17
19
21
23
25

4

5

6

7

8

9

10
12
14
16
18
20
22
24
26

CH07 LO/CH15 HI
CH03 LO/CH11 HI
CH07 HI
CH03 HI

1

2

3

4

5

6

7

8

9

10
12
14
16
18
20
22
24
26

ODAC 1
LL GND
MUX 04
MUX 06 MUX 07

D GND D GND

Connector J5 and

Jumper Pad J9

ODAC 3

LL GND

MUX04
MUX06 MUX07

D GND D GND

Connector J7 and

Jumper Pad J11

Figure B-4. Pin Layouts and Assignments for STA-1800U Connectors J4 to J7 and

Jumper Pads J8 to J11

LL GND

MUX 05

LL GND

MUX05

B-4 Connector Pin Assignments

C

DriverLINX Configuration

Notes

This appendix contains the following sections:

●

●

●

●

●

●

●

Configuration

The following section describes detailed information about how
DriverLINX implements features of the Keithley DAS-1800AO A/D
boards.

Configuration

DAS-1800AO boards.

Special Device Settings

the DAS-1800AO boards.

Implementation Notes

features of the DAS-1800AO boards.

Analog Input Subsystem

DAS-1800AO analog inputs.

Analog Output Subsystem

configure analog outputs.

Digital Input and Output Subsystems

DriverLINX is used for configuring digital inputs and outputs.

Counter/Timer Subsystem

counter/timer functions.

— describes how DriverLINX works with

— describes settings used specifically for

— describes how DriverLINX implements

— describes how to configure

— describes how DriverLINX is used to

— describes how

— describes some of DriverLINX

Configuration C-1