Tektronix DAS-4 User guide

DAS-4

Part

DAS-4

Number:

24888

Last

Copyright

KEITHLEY

440

Taunton,

METRABrrUASYSTlDAC

Myles

Telephone

FAX

Revision

Edit:

Standish Boulevard

Massachusetts

A

July,

1987

@

1987

02780

5081880-3000

508/880-0179

WARRANTY INFORMATION

All

products manufactured

and

worksmanship for a period of one year

purchaser.

Any

product that

option of Keithley MetrdByt'e,

by

Keithley MetraByte are warranted

is

found to be defective

be

repaired

products damaged by improper use.

hm

or

replaced.

the date

within

This

against

of

delivery to the ongind

the

warran@

defective materials

period

does

not

will,

apply to

at

the

New Contact Information

Keithley Instruments, Inc.

28775 Aurora Road

Cleveland, OH 44139

Technical Support: 1-888-KEITHLEY

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

Fax: (440) 248-6168

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

Table

of

Contents

...

Section 1 INTRODUCTION 1-

1.1

SUMMARY

Section 2 INSTALLATION 2- 1

2.1

BACKING UP

2.2

HARDWARE

Section 3 PROG€L"G

3.1

PROGRAMMING DAS-4

3.1.1

3.1.2 STARTING

3.1.3 READING

3.1.4

3.1.5

3.1.6

3.2 LOADING "DAS4.BIN"

3.3 FORMAT OF

3.4 EXAMPLES

3.5 MODEO- INITIALIZE

3.6 MODE

3.7 MODE

MUX

3.8 MODE

3.9 MODE MEMORY ON INTERRUPT

3.10 1

3.1

3.12 MODE

3.13 MODE

3.14 MODE

3.15 SUMMARY OF ERROR CODES

3.16 PROGRAMMING EXAMPLES

3.17 OTHER PROGRAMS AhD UTILITIES

3.18 ASSEMBLY LANGUAGE PROGRAMS AND CALLS

LANGUAGES

3.19 A NOTE ON EXECUTION TMES

3.20 MULTIPLE DAS-4's

I/O

THE THE

SOME

.....................................................

MODE MODE

OF DAS-4 FUNCTIONS

THE

DISK

INSTALLATION

.................................

........................

............................

..................................

ADDRESS MAP

THE

DAS-4 STATUS REGISTER DAS-4 CONTROL REGISTER

BASIC PROGRAMMING TIPS

THE

MACHINE LANGUAGE CALL ROUTINE

OF

DAS-4

A/D

CONVERTER

A/D

DATA

........................

....................

...........................

......................

....................

..................

................................................

THE

OF

CALL STATEMENT

THE

USE

OF

THE CALL ROUTINE 3-12

.....................

.........

..................................

1

.

SET MULTIPLEXER SCAN LIMITS

2

.

DO

ONE

A/D

CONVERSION

3

.

DO

N

AJD

CONVERSIONS DIRECT TO ARRAY

4

.

DO

N

A/D

CONVERSIONS

AND

..............

INCREMENT

TRANSFER TO

..................................

5 . ANALOG TRIGGER FUNCTION

6

.

TRANSFER DATA FROM MEMORY TO ARRAY . 3-25

7 - READ

8

.

READ DIGITAL

9

.

WRITE DIGITAL OUTPUT

STATUS

..............................

INPUTS

IP1-3

OP1-4

................

.................

...............

.........................

FOR

THE DRIVER MODES

....................

IN

OTHER

.............................................

.

IN

ONE SYSTEM

COMPILED BASIC

....................

......

...

.

3-13 3-15

3-17 3-19

.

1

1-1

2-1 2-1

3-

1 3-1 3-2 3-2 3-3 3-3 3-4 3-5

3-6 3-9

3-21 3-23

3-27 3-28

3-29 3-30 3-31

3-31 3-32

3-32 3-33

.

Section 4 APPLICATIONS

4.1 CHANNEL INPUTS

4.2 MEASURING VOLTAGE

4.3 4-2OmA CURRENT LOOPS

4.4 THE REFERENCE

4.5 USING DIGITAL INPUT/OUTPUT

4.6 ADDING

MORE

......................................

.................................

.......................................

ANALOG INPUTS

................................

.........................

........................

1

4-

1 4-1 4-2

4-4 4-4

4-4

4-5

4.7

INTERFACE TO TRANSDUCERS, THERMOCOUPLES ETC.

4.8 POWER OUTPUT

4.9 PRECAUTIONS IN USE - NOISE, GROUNDLOOPS

OVERLOADS

..............................................

FROM

THE

DAS-4 CONNECTOR

..........

AND

...

4-5

4-6

Section 5 CALIBRATION AND TEST

AND

5.1 CALIBRATION

5.2 SERVICE AND REPAIR

5.3

TECXNICALASSISTANCE

Appendix

A.1 MAINI/OCO"ECTOR

A.2 REAR

Amendix

AA

B.l POWER CONSUMPTION B.2

B.3 B.4 SAMPLE

B.5 B.6

B.7

B.8 POWEROUTPUTS B.9 GENERAL ENVIRONMENTAL

Appendix C STORAGE

A

CONNECTIONS A- 1

VIEW

B

SPECIFICATIONS

ANALOG

A/D

SPECIFICATION

OF

INPUT

HOLD

REFERENCE VOLTAGE DIGITAL INTERRUPTINPUT

I/O

...........................................

TEST

..................................

.................................

DAS-4

CONNECTOR

.................................

SPECIFICATIONS

....................................

AMPLIFIER..

OUTPUT

.....................................

......................................

OF

INTEGER VARIABLES

...............................

......................

.......................

............................

.........................

...........................

5- 1 5-1 5-1 5-1

A-1 A-3

--

B-

1

B-1 B-1

B-1 B-2 B-2 B-2 B-3 B-3

B-3

c-

.

1

..

11

DAS-4

MANUAL

INTRODUCTION

Section

1

INTRODUCTION

1.1

MetraByte's

IBM

6300 series, Zenith, Compaq, PC's Limited, Tandon, Televideo etc. The

and can be connector that projects through the rear of the computer. The following functions are implemented on the

1.

2.

SUMMARY

PC-PC/XT-PC/AT & PS2 Model 30 P and other bus compatible computers e.g. A.T.&

DAS-4

fitted

is a 8 channel 8 bit hi h speed

in a

OF DAS-4

"half'

slot. All connections are made through a standard .37

FUNCTIONS.

A/D

converter and digital

I/O

DAS-4

board for the

board is

DAS-4:-

An

8

channel, 8 bit successive approximation

+/-5

volts

input of each channel is are single ended volts and brief transients of several when the computer power is off. microseconds

30,000

7 bits of port

channels/sec

TTL

of

3

bits.

with

max.)

and depending on the speed of the software driver, through puts of

are

digital

VO

a common ground and can withstand a continuous overload of

attainable.

are provided composed of one output port

with

a resolution of 0.03906 volts

hundred

A/D

AD

converter with samplehold. The full scale

volts. All inputs are fail safe

conversion hme is typically

(39.06

20

of

4

millivolts). Inputs

i.e.

open circuit

microseconds

bits and one input

5"

D

+/-30

T.

long

male

(30

up

to

1

precision

3.

reference. This output

A/D

Full

4.

An external interrupt input is provided that can select any of the and allow user programmed interrupt routines to provide background data acquisition interrupt driven control. The DAS-4 includes status and control registers that make intempt handshaking a simple procedure. The connected to any external

IBM

5.

The following utility software for 5-1/4" floppy request)

1. A machine language

1.

Registered

P.C. bus power rear connector. This makes for simple addition conditioning circuits, expansion multiplexers etc.

:

-

110

channel functions via BASIC CALL. The I/O driver can select

trademarks

+5.OOv

Scale

disk

of

(+/-O.~V) reference voltage output is derived from the

can

trim

source/sink

pot.

5mA

and

is

the voltage

is

IBM

'ITL

(+5,

+12 & -12v) is provided along with

compatible with

I/O

driver (DAS4.BIN) for control of

International

Business

interrupt

compatible trigger source.

DAS-4

Machines

is provided

DOS

2.0 and higher revisions (3-1/2" media available on

Corporation.

input is positive edge triggered and may

all

other

of

user designed interfaces,

on

a double sided 360K PC-DOS format

AD,

and digital

A/D

converter

slightly adjustable

P.C. interrupt levels 2-7

YO

connections

input

by

the

or

be

on

the

signal

INTRODUCTION

DAS-4

MANUAL

multiplexer channels, set scan limits, pexform conversions, interrupt driven conversions and scans. The driver source

is

listing, DAS4.ASM,

2. Initial setup and installation aids.

3. Calibration and test programs.

4.

Electronic strip chart program.

5.

Slow

speed data logging program.

6. Other examples and demonstration programs. The DAS-4 is simple, inexpensive and easy to use.

acquisition and control applications. 8 bits provides a span

corresponding to than 1% bipolar resolution which is often adequate for many measurement, control and graphing applications. The DAS-4 is hardware compatible with MetraByte's DAS-8 which provides higher resolution through

To

extend the capabilities of DAS-4 the following expansion modules can

insulation displacement cable

SCREW "AL CONNECTOR BOARD

1.

connected to miniature screw terminal connectors. The digital monitored available for amplifiers, filters, and other user supplied circuits. The screw terminal connector board is MetraByte part number STA-08.

-5

by

L.E.D.'s and a small bread board area with +/-12v & +5v power is

also provided

volts of input, and +127 corresponding to +4.96 volts.

the

use of a 12

to

the main

on

the disk.

bit

A/D.

37

software commanded

It

is ideally suited to low precision data

D

VO

connector:-

-

All

VO

lines on the rear connector are

of

AD

255 bits with -128 bits

This

provides better

be

connected via flat

YO

port lines

are

EXPANSION MULTIPLEXER

2. EXP-16 multiplexes 16 differential inputs to a single analog output suitable for

to

any

of

connection cascadable so that up to

total

a instrumentation amplifier 200

sensor is also included directly connected

resolution of a

ISOLATION AMPLIFIER

3. channels and measuring off ground voltages protecting input circuits. Up to 32 The ISO-4 also includes cold junction compensation and can be used measurements. The

MetraByte also offers many optional software packages that can enhance DAS-4. Their menu driven user interfaces eliminate programming and give fast results. Most include the capability of generating data and some also provide analytical capabilities as well. For a full description, see our catalog. All of ACQUIRE, LABTECH STORAGE SCOPE,

of 128 channels. The expansion multiplexer board includes a low drift

or

1000

(other

12

can

our

software that works

the analog input channels of DAS-4. EXP-16 boards

8

EXP-16

with preselected switchable gains of

gains

can

for software compensation of thermocouples which can be

to

EXP-16, although the DAS-4 resolution will not provide the fine

bit

A/D

board when used for thermocouple measurements.

be

connected directly to DAS-4. This

ISO-4

provides gains ranging from

NOTEBOOK,

?TOOLS

AND

be

resistor programmed). A cold junction compensation

-

MetraByte's model ISO-4 provides 4 isolation amplifier

(500v

Lotus

with

DAS-8 will also

and CTOOLS.

INSTRUMENTATION AMPLIFIER - The

boards can be attached to a single

is

an

max. isolation) or eliminating ground loops or

IS04

expanders may

1-2-3 compatible data files, immediate graphing

work

UNKELSCOPE, UNKELSCOPE

be

connected to one DAS-4.

1

to

1000.

with DAS-4 and includes LABTECH

DAS-4

0.5,

1,

excellent accessory for

for

providing

2,

10,

thermocouple

the

ease

JR.,

50,

of

SNAPSHOT

are

100,

use of the

of

1-2

-

DAS-4 MANUAL

Section

I

NSTAL LATlO

2.1

The utility software supplied with DAS-4 is compatible Model 30 drives, please contact MetraByte, it is available at no charge. It is advisable to make a back up copy before using the software. For a direct back up, use the DOS DISKCOPY utility or alternatively COPY to a directory of your choice, the DAS-4 utility software is not copy protected. you should misplace or damage the disk, please contact MetraByte for a free replacement.

BACKING

with

DOS

2.0

*.*

to a pre-formatted disk. For a hard

UP

THE DISK

thru

3.3 revisions.

If

you need a 3-1/2” disk compatible with the PS2

2

N

in

DOS 2.0 (360K DSDD) format which is

disk,

simply use COPY

INSTALLATION

*.*

to transfer

If

for any reason

2.2

DAS-4 utilizes 4 consecutive address locations in used by internal DAS-4’s

anywhere in the I.B.M. space extends be fully occupied.The PC AT’S

100-3FF), some space also allows use of more than one DAS-4 for standard lBM devices are detailed below:-.

HARDWARE INSTALLATION

VO

and your other peripheral cards,

I/O

address can be set by the

PC decoded

fiom

decimal 512-1023 (Hex 200-3FF) which is much larger than is ever likely to

XT

compatibles

ADDRESS(Hex1 DEVICE ADDRESS(Hex1 DEVICE

000-

1

FF

200-20F 2 10-2 17

220-24F 278-27F 2FO-2F7 2F8-2FF 300-31F 320-32F

Internal system

Game Expansion unit Reserved Reserved LPT2: COM2: Prototype card

disk

Hard

BASE

I/O

VO

address space is larger and extends from 256-1023 (Hex

also

follow this expanded

ADDRESS D.I.P. switch to be on a 4 bit boundary

space. The PC and PC/XT’s expansion

in

378-37F 380-38C 380-389 3AO-3A9

3BO-3BF 3CO-3CF 3DO-3DF 3EO-3E7 3FO-3F7 3F8-3FF

VO

space. Some

so

to avoid conflict with these devices,

VO

a single computer. The reserved

I/O

addresses

space capability. Such a large

LPT1: SDLC comm. Binary comm. Binarycomm. Mono dsp/LPT Reserved

Color graphics Reserved Floppy disk COM1:

2

1

:

will

already be

UO

address

addresses

the

This covers

1/0

peripherals e.g. special hard disk drives, special graphics boards, prototype cards etc. they

may

be making use

standard

of

IBM

I70

options (most compatibles are identical),

I/O

addresses not listed in the table above. Memory addressing is separate

but

if

you

have other

2-

1

INSTALLATION

from

I/O addressing computer. Usually, a (Decimal Hex

300-3

768

or

784). (Note

1F

address space and would conflict,

so

there is no possible conflict with any add-on memory that may

good

choices is to put the DAS-4 at base address Hex

if

you have an

IBM

prototype board plugged in,

&H330

or &H340 would be a good alternative

DAS-4

&H300

it

MANUAL

be

in

or

&€-I310

makes use of the

your

in this case). As an aid to setting the base address D.I.P. switch, a graphical switch position display program, INSTALL.EXE, can be run

the DOS prompt.

To

run

the installation aid program,

from

type:-

A>INSTALL

When you get the "Desired base address?" prompt,

will

format and press return. The program check for possible conflicts with standard

the

picture of understand

correct positions of the toggles

the

details, see Fig.

2.1

for an explanation of base address switch settings. Set the

round your address to the nearest 4 bit boundary,

IBM

YO

on

the base address DIP switch.

your choice in decimal

devices (and warn you

if

so)

or

&H---

and draw a

If

you like to

type

in

DAS-4 base address dipswitch to correspond with your choice. The

only

other setting on the DAS-4 is the choice of-'hardware intempt level.

going to use interrupts in your progamming (mode

jumper can

a level that

be

left in the

is

not in use by any other peripheral board (see Section 3.5, mode

"X"

(inactive) position.

If

you intend to use interrupts, set the jumper to

4

of

the DAS4.BIN driver) the interrupt

If

you are not

0

for more

information).

To

install the

"Guide

to Operations" manual for your computer if you are not already expert at this maneuver).

Remove a vacant back plate by undoing the screw at the top and plug the DAS-4 the backplate. The board should not

board,

be

placed in the short slot next to the power supply on a

TURN

will

OFF

fit

THE

POWER

in

any of the slots

on

your computer and remove the case (See the

of

the

IBM

PC,

in

XT

or Portable computer

PC/XT.

This slot is intended

and secure

but

for the expansion interface and has slightly different signals from t5e others, DAS-4 will not work properly into any socket but

is

now complete.

although

it

will

You

it

will

not cause any damage. On the PC/AT, DAS-4 can

not make use

of

the extended

AT

bus interface connector. Installation

be

plugged

may plug any of the DAS-4/8 accessories or your own cable into the

37

in

it

pin D connector on the rear.

Remember,

including

can cause costly damage

BASE ADDRESS

98765432 (DECIMAL

........

........................

.......

.............................

......

..................................

.....

.......................................

....

............................................

...

.................................................

..

......................................................

...........................................................

TURN

fhe

DAS-4.

OFF

Never

THE

POWER

try

to

install

to

the electronics

SHOUN

ADDRESS EQUIVALENT

whenever installing

or remove any peripheral

of

your computer and/or the DAS-4 board.

SET TO

A2 A3

A4

A5

A6

A?

A8

A9

hH300

768)

DEC

16

128

256

512

I

MAL

4 8

or

removing any peripheral board

board

VALUE

ON

POSITION

with the power on as it

IN

OFF

POSITION

IS

ZERO

IN

THE

234

I

NTERRVPT

2-2

567X

LEVEL

FIG.

INTERRUPT

PLFICE

"

X"

-

2.1

JUMPER

JUMPER ON

I

NACT

I

VE

6ASE

~ICIDRESS

BLOCK

LEVEL SELECTED

PARK

I

NG

POS

I

TI

d

iNTERRUPT SELECTION

ON

PROGRAMMING

Section

3

PROGRAMMING

3.1

At

-

BASIC these level languages have equivalent instructions functions demanding, this can require many lines data format and architecture routine "DAS4.BIN" is included BASIC by a single line CALL statement and covers the majority of common operating modes. The various modes of

check data, and perform frequently performs read data and increment the multiplexer.

Using the DAS4.BIN driver saves a lot of programming time and has some other benefits as well. For instance, the driver supports data collection on interrupt from an external source. Note that BASIC has no intempt processing functions and

using these methods is only available using

PROGRAMMING DAS-4

the lowest level, DAS-4 can

are

the

INP

@)

usually

a

involves formatting data and dealing with absolute

the

CALL routine select all the functions

sequence of operations required to perform an

be

and

OUT

of

the DAS-4.

in

used

programmed

of

the DAS-4 software package. This may

using

X,Y

functions. Assembly language and most other high

(IN

code and necessitates an understanding

To

simplify program generation, a special

sequences

the

of

CALL routine.

YO

input and output instructions. In

AL,DX and

instructions. An example is Mode 2 which

so

called "background" data collection

OUT

of

MI

conversion, check

DX,AL). Use of these

VO

addresses. Although not

the DAS-4, format and error

of

be

accessed

the devices,

A/D

I/O

driver

from

status,

INP

Both methods of programming using same result, and

the

CALL routine much simpler to implement. If you need non-sequential channels, special interrupt routines etc. you can modify the DAS4.BIN driver to your requirements. The fully commented assembly source is supplied on the utility

(DAS4.ASM) and can is

a good starting point for assembly language programmers who wish to modify

driver. For the steps involved in generating a BLOADable DAS4.BIN

instructions prompt).

in

you

are free to choose either although usually

be

re-assembled using the Microsoft Macro-Assembler (any version) and

the

file HOWTO.BIN

and OUT functions and the CALL routine achieve the

the

BASIC proFammer will find

to

perform specialized scans such

the

file,

follow the

file

on the disk (enter

TYPE

HOWTO.BIN after the DOS

as

disk

standard

3-

1

PROGRAMMING

DAS-4 MANUAL

3.1.1

IIO

ADDRESS

First

of

all let’s

take

ADDRESS

Base Address

The

DAS-4

addresses, but the register format and functions are identical. compatibility with MetrdByte’s model with existing software e.g. Labtech Notebook etc. that has drivers for the

3.1.2

STARTING

has

MAP

a look at the

+

+1

+2

+3

an

VO

address map that is a subset of the

THE

AID CONVERTER

OF

0

DAS-4

VO

address map

READ

Always zero

A/D

data Status register Control register Status register

(same as Base

of

the

DAS-4:-

(8

bit) Start

+

2)

WRITE

Start

12

bit

AD AD

DAS-8,

This

DAS-8,

12

bit

AJD

board,

so

conversion conversion

that the

it uses only the fust

is to maintain hardware

DAS-4

can

be

4

used

DAS-8.

An A/D ADDRESS

any case. The ensuing can

The

is that

It

is a good precaution

write

Starting

conversion is initiated by writing to either location

+

1.

The value of any data written to these locations

be

monitored

DAS-4

it

will

to

BASE ADDRESS

an

A/D

from

uses the

not

start

conversion:-

AD7574 8

xxxl0

or:-

xxxl0

A/D

conversion will take about

bit

7

of

the status register.

bit

A/D

converter. One of the design “features” of this converter

another conversion until data

to

perform a read of the

to

start a new conversion.

OUTBASADR%, OUTBASADR%

+

0

1,

AD

0

BASE

20

microseconds to complete, its progress

from

the

previous conversion has been read.

and throw away the data before issuing a

ADDRESS

is

irrelevant and will

+

0

or

be

BASE

lost

in

3-2

DAS-4

MANUAL

PROGRAMMING

3.1.3

READING

After the end

+

1.

The data format is:-

-

BIT POSITION

(BASE ADDRESS + 1) B1 B2 B3 B4 B5 B6 B7 B8

Location compatibility

The

BINARY

0000 0000

0100

BASE ADDRESS + 0

A/D

data

OOOO

0001

0000

THE

AID DATA

of

conversion the data

-

D7

(MSB)

with

the

12

bit

A/D

bits

B 1-B8

HEX

correspond to

DECIMAL ANALOG

00

01

40

0

1

64

from

the

A/D

may

be

read

from

location

-

D6

will always return zero when read, this is to maintain

data

of

-

D5

the

DAS-8.

an

offset binary code:-

_.

D4

-5.000

-4.961

-2.500 v (-1/2

-

D3

INPUT

v

(-Full

v

D2

VOLTAGE

scale)

BASE ADDRESS

D1

DO

1000

0000

1000

0001

1

loo

0060

iiii

A

sequence of

xxxl0 INP(BASADR% + l),

XXX~O

3.1.4

The

I/O BIT POSITION

THE DAS-4 STATUS

status register provides information on the operation of

location

(BASE ADDRESS

BASE ADDRESS

80

81

CO

*

FF

BASIC

V = (D%-128)*5/128

+

2) EQC

128 129

192

255

instructions to read the data and

D%

REGISTER

+

2

(or

BASE ADDRESS + 3)

-

D7

-

D6

IP3

-

D5

IP2

+/-0

v (zero)

4.039

+2.560

~4.961

'read data 'scale to volts

v

turn

it into volts

-

D4

LP1

(+1/2

(+Full

in

DAS-4.

and

bits

has

-

D3

IRQ

scale)

would

It is a read only register at

the

D2.

34A2 MA1

be:-

following format:-

D1

-

DO

MA0

The bits have the following significance:-

PROGRAMMING

DAS-4

MANUAL

EOC:

IP3

-

IP1:

IRQ:

MA2-MAO:

End of Conversion.

A/D

is busy performing a conversion. Data

should not

invalid. Wait for the

sigmfying valid data available.

These bits correspond to the three port lines for any

After generation of an interrupt to the processor

IRQ

is

(0)

low provides a means

"handshaking"

These bits provide the current analog multiplexer channel address as follows:-

MA2

be

IP3,

digital

set to logic high

by a write

MA1 MA0 CHANNEL

0 0

1

If

EOC

is

high

(Logic

read

in

this

condition

EOC

to

return

digital

IP2 and IP1. They may

input data.

(1).

It

is reset

to

DAS-4

the control

of

acknowledging or

interrupts.

register.

0

1

0

1

as

to

it

1)

will

logic

input

be

used

to

logic

This

the

be

0.

0 0

0

1

0

1

3.1.5

The control register sets the multiplexer (channel) address, enables and disables intempts and provides output data to the write only register located at

The data format of the control register is:-

-

BIT POSITION (BASEADDRESS+2)

The bits have the following significance:-

THE

DAS-4 CONTROL

OP4-OP1: These bits correspond to the four general purpose

REGISTER

4

general purpose digital outputs OP1-OP4. The control register is a

UO

address

-

D7 OP4 OP3 OP2 OP1

digital output lines OP1 thru can be used for external control functions e.g. driving an input sub-multiplexer to increase the

number mux. expand the system to 128 channels.

of

on

BASE ADDRESS + 2 (same location as

-

D6

analog input channels. A

each

-

D5

of

DAS-4's 8 analog channels can

-

D4

OP4.

-

D3 INTE

These lines

16

channel

status

D2-

MA2

D1 MA1

register).

DO

MA0

3-4

DAS-4

MANUAL

PROGRAMMING

INTE:

MA2-MAO:

DAS-4

of the selected

INTE

,

input (pin level and are positive edge triggered. programmer's responsibility to set up an interrupt handling routine, intempt vectors and initialize the

IBM

register will clear the register.

These bits select the current analog multiplexer channel address as follows:-

generated interrupts are enabled onto

IBM

P.C.

interrupt levels

=

1

(logic high). Interrupts are disabled if

=

0

P.C.

MA2

(logic low). Interrupts

24)

are passed through to the selected

8259

processor board. Writing to the control

interrupt controller

IRQ

MA1

MA0

from

bit

of

CKANNEL

the

It

the

2-7

INT.IN

is the

on

any

if

the

status

The multiplexer channel address One further note about the control register. During power up

line of the IBM interrupts are disabled, sets address to zero.

3.1.6

programming, but may

SOME

Some BASIC commands which

Data read

ANDed

until a non-zero result is obtained. This is an excellent way program

This command

with

checks the timer

P.C.

is

asserted, the DAS-4 control register is cleared. This insures that

BASIC

a pseudo-interrupt. After execution

PROGRAMMING

be

useful with

WAIT

with

wait

ON

port, n[,m]

at

the port

"n".

If

until some desired external condition is attained.

TIMER

is

only available in DOS

to

can

be

determined at any time by reading the status register.

digital

outputs

OP1-4

to zero and sets the multiplexer channel

TIPS

you

may not have used frequently in the come

DAS-4

is

exclusive-or'ed (XORed) with integer expression "m" and

the result is zero, BASIC

(n)

GOSUB

see

if

the condition >n

line

are:-

2.0

loops

and above. In effect

of

each BASIC statement, BASIC

(

1

<

n

<

86,400

of

the

IBM

back and tests

of

seconds) is satisfied.

P.C.

the

making

it

provides

when the

of

port again

your

you

If

RESET

DAS-4

ordinary

3-5

PROGRAMMTNG

it

is, control passes

polling of the timer

TIMER ON

Trapping is disabled by:-

to

the subroutine, otherwise the next line

is

called trapping and is activated by:-

is

executed.

DAS-4

MANUAL

This

3.2

TIMER

Note that trapping only occws while your BASIC program is executing (unlike a true interrupt) and can execution time. is a convenient way

If

you

wish to program an than the more powerful CALL routine, the following sequence should followed:-

xxxl0

xxx20

xxx30 D%=INP(BASADR%+l) 'read

Note that looping while the in interpreted BASIC conversion time of compiled using the BASIC COMPILER, the execution time is reduced to a point where the status test

line

xxx30.

OUT

IF

LOADING THE

OFF

be

slightly delayed by statements that require a

If

you

need

to

sample

to

do

it.

A/D

BASADR%

INP(BASADR%+2)>=&H80

as

20

of

+1,0

A/D

the interpreter execution time greatly exceeds the

microseconds. However,

line

xxx20

at

long intervals the

conversion using BASIC

converter is still busy (line.

is essential

MACHINE

ON

TIMER command

INP

and

OUT

'start

A/D

conversion

GOT0

xxx20 'status test loop

A/D

data

xxx20)

if

the program is subsequently

to

avoid returning enoneous data in

is not required

LANGUAGE CALL

lot

of

rather

be

A/D

ROUTlN

As

the previous simple example tedious to implement although a lot of the required programming could subroutines. Use

circumvents the execution time delays of interpreted or compiled BASIC, and

background data collection using intempts.

In

order

You

must avoid loading BASIC (watch out for BASICA.EXE if you Disk". work and damage will result, but to get things going again you seconds before turning

in

general and would apply to loading any CALL or information provided

When you load the DAS4.BIN CALL routine, you have two options depending on the size of

your

If

them,

available memory. Due to the design of Microsoft Basic, the maximum memory se,ment

E

"DAS4.

of

the CALL routine described in the

to

make use of the CALL routine "DASABIN",

you do interfere with another program's use of memory, the CALL routine will not

most

likely your PC

on

SAVE

them

before

in

the "I.B.M. BASIC MANUAL".

BI

N"

shows,

it

over any part of memory that is being used by another program e.g.

will

again).

you

direct

do

strange things for a second or two and then hang up

Here

is

run

them!

UO

using BASIC

are

using

some

advice,

Note that the information given

GW

will

have to turn off power and wait a few

when

USR

INP

and

this

section avoids these problems,

it

must first

BASIC) print spoolers or

you

write programs with

routine and supplements the limited

OUT

can

be

loaded into memory.

in

be

somewhat

be

handled

also

permits

"RAM-

CALLS

this section is

(No

in

3-6

DAS-4

MANUAL

PROGRAMMING

that BASIC

following message on power up

BASIC

The exact number of "Bytes free" varies with the version of BASIC(A) and DOS but is usually greater available. When the number of memory bytes free your PC's memory is already

than

its possible routine by further forced contraction of the BASIC workspace and loading the routine at the end

of

the newly defined workspace. DAS4.BIN will occupy about 1852 bytes but to keep things

simple, let's clear a Step 1 is

DOS:-

Note the number return

is

able to use is

The Version D1.10 Copyright 61807 Bytes free

than

60000

bytes

64K

maximum workspace.

2K

to

work

out

how much memory BASIC is able

A>

BASIC(A)

of

bytes free

to

DOS and this time load BASIC(A) with the optional

A> BASIC(A)

64K

bytes.

or

from DOS by entering A> BASIC(A)

IBM

Personal Computer Basic

if

an

excess of memory over and above what BASIC can use is

fully

utilized and BASIC

(2048 byte) space for

in

BASIC's greeting messages. Next

/M:

WS

If

where

BASIC

IBM

If

this

it

WS

is

using

Corp. 1981,1982

is

less than

is

is the case, you

a number (not a variable)

its

maximum

60000,

adjusting to

will

to

use. First just load BASIC(A) from

do

/M

parameter:-

64K

you

will

:-

this is an indication that

this

condition by using less

have to load the CALL

a SYSTEM command to

get the

Try

setting the WS (workspace) parameter

free in the greeting message. The objective is to determine the workspace that must

to

reduce the bytes free by at least 2048 bytes. Once BASIC(A) by specifying this workspace or include a CLEAR command right at the beginning of your program e.g.:-

xxxl0 CLEAR,

Next, we need Microsoft derived BASIC, this can be found &W11 and &=lo which hold the current BASIC segment which we can call SG. determined as follows:-

The segment address at which we can now load the working space i.e.:-

to

know what segment BASIC is occupying in memory.

xxx20 DEF SEG

xxx30

xxx40

SG

SG = WS/16 + SG

WS

=

0

=

256*PEEK(&H511) + PEEK(&KS10)

to

30000 or 4oooO and then note the number of bytes

be

specified

this

is determined

from

the contents

'define current segment

before reading absolute addresses 0000:0510

the

CALL routine will simply

'remember segment addresses

on

are

16 bit boundaries

of

absolute memory locations

=

&

0000:0511

0000

you

can either load

In

all

versions of

SG

be

at

can

the

be

end of

The routine can now

xxx50 xxx60 BLOAD "DAS4.BINtt,0

be

loaded as follows:-

DEF

SEG

=

SG

'loads routine at

SG:0000

3-7

PROGRAMMING

DAS-4

MANUAL

A BLOAD

CALL

the

parameters

Note that the starting address of the preceding to associate with the device and would distinguish it might be

(FORTRAN, PASCAL

the name of the external routine that the linker will compilation.

3.19). Returning

defined by the last routine is located. somewhere in a program before entering the

your

program,

DEF

duplication. This precaution can save a computer!

must

be

used as we are loading a binary (machine language) program. Once loaded,

can

be

entered

MD%,

D%, FLAG%

xxx70

xxx80

xxx90

in

interpreted

DEF SEG

in

the same program.

statement. We have chosen

DAS4.0BJ

to interpreted

DEF

Be

as

many times

prior

to

the

as

CALL

DEF SEG = SG DAS4 CALL DAS4

Microsoft

=

0

@ID%,

D%(O), FLAG%)

BASIC, DAS4

CALL

etc.) the significance of

is supplied on the software disk for this purpose (see Sections 3.18

BASIC, DAS4

SEG

careful that

routine from the current segment

In

compiled

statement that tells your

you

BASIC,

is the offset (actually zero)

do not inadvertently redefine the current segment

CALL.

it

is good practice to immediately precede the

SEG

statement (the same one you preceded your

lot

of wasted time and frustration from crashing your

needed

DAS4

in

sequence as follows:-

is a variable that specifies the memory offset

as

from

Quick Basic or other compiled languages

DAS4

in the

If

you

the program after initializing the call

of

as

defined

a

name,

any other

be

BASIC

are

BLOAD

as

it

makes

CALLS

CALL

is different.

looking for when linking after

from

interpreter where the

using

DEF SEG

statement

with) even at

in

the most recent

CALL DAS4

to other routines that

In

this case,

the current segment as

easy

it

is

&

CALL

in

other parts

by

the appropriate

the

cost

of of

Another important detail to understand is that

BASIC

available

end up loading hang up the computer.

and later load compensating reduction in the workspace memory is limited, setting up a workspace that is a considerable amount less than what is

available

than the

completely into

DOS

loads

contraction

memory

happen on a machine

the workspace

little on

doing.

loading and using the

use

The

have plenty

routine outside the

beginning.

working area up whereas we must

memory down.

our

BASIC

is

a simple precaution. Another precaution in this regard occurs

IBM

P.C.)

that do not contain most of

RAM

and the

from

To

as

a "front end" to your own programs.

second method

BASIC

the top of memory down. The

of

the

minus

the

that used

is

the only way

complex side, but like

further assist you,

of

memory (generally

BASIC

For

example we might choose

If

we attempt

routine over the end

Be

careful this does not happen inadvertently

with

DEBUG

in

the

form

of a

program space load from the bottom of memory up

BASIC

with

of

program space will automatically take place as

by

DOS

and

less than

of

loading the

run

and list the file

CALL

loading the driver

routine and ready made loading and ininalizing code that

256K

workspace.

or some other memory resident program without making a

BASICA.COM

128K

all

In

CLEAR

set

aside space for

to

CLEAR

of the

BASIC

(WS)

the

free

BASICA.EXE

of memory

CALL

things they

is

somewhat simpler

or more) and you have the

this case choose a segment that has

&H6000

sets working space from the bottom

our

subroutine from the top

more space than

program, data space and stack and will

declaration in

BASIC

memory ends up

in

ROM.

and a

BASICA.EXE

becomes less

in

which case further forced contraction

routine. These considerations all sound a

are

not once you understand what you are

EXOO.BAS.

which

is

at 384K. Then proceed as follows:-

is

actually available, we will

if

you

are

memory limited

the

CLEAR

These machines load

in

than

This gives you an examples

to

follow and applies when you

luxury

statement. When

on

computers (other

file.

BASICA.COM,

and

BASICA.EXE

the

middle and some

soon

as the total

MK.

This

can

of loading the

2K

bytes clear at its

of

the

of

BASIC

easily

of

you

can

CALL

3-8

xxxl0

DEF

SEG

=

SrH6000

'Sets

up

load segment

DAS-4

MANUAL

PROGRAMMING

xxx20

-30 DAS4

-40

xxxxx

xxxyy xxxzz

An

example of

workspace,

DEF

locations. Usually obliteration of some of the routine code and a computer hangs up, and

floor

large amounts of memory may memory than the example above. resident space in memory

SEG statements in

again. Note that memory resident programs such

in

UP.

be

memory for additional programs such as

BLOAD "DAS4.BIN",O

=

0

DIM D%(3)

I111

Ill1

llll

DEF SEG CALL DAS4

etc.

this

approach is contained

sure you really do have an unused

any

=

&H6000

(MD%,

EXO.BAS

clash with another program's use of the same memory

and experiment

'Loads at

D%(O),

in

file

failure

the

only cure

run

than

earlier versions and

is

to

switch

out of space or require loading the

Also

higher revisions of

6000:oooO

FLAG%)

EXO.BAS.

2K

of

with

Before

memory at

loading the

you

try

384K.

CALL

loading outside the

You

can change the

routine at other

results

to exit and return from the routine. The

off,

wait a few seconds

as

Borland's Sidekick will raise the loading

BASIC(A).

may

require

DOS

In

this case even machines with

with

loading the

and

turn

on the power

DASABIN

additional features use more

CALL

even higher in

routine higher

in

3.3

If

the the subroutine is located. The

As

memory as defined defme the current segment to correspond with the starting address of the this offset is always zero and

The

the addresses

The

BASIC's

must be met:-

1.

FORMAT

you

are

new to using

CALL

CALL,

explained

three

CALL

transfers execution to the machine language (binary) driver routine. Prior to entering

variables within brackets are known

routine unloads these pointers from the stack and uses them to locate the variables

data space

The

CALL

knows

from

OF

THE CALL STATEMENT

CALL

the

DEF SEG

xxxxx

the order

CALL DAS4 (MD%, D%(O), FLAG%)

in

the previous section,

ir!

the last

of

the Variables (pointers) are passed in the sequence written

so

data can be exchanged with them. Three important format requirements

parameters are referenced by position. The subroutine

nothing of the names of

of

statements, this explanation

=

SG

statement sets

CALL

statement for the

DAS4

DEF

SEG

statement.

DAS4

their pointers

=

0.

the

variables, just their locations

on

the stack.

may

assist you in understanding how

the

segment address at which the

DAS4.BIN

is the address offset from the current segment

In

as

the

CALL

driver must

all

of

our

parameters. On executing

examples, we have chosen to

be

of

CALL

to

CALL

the form:-

of

routine, therefore

the

CALL,

BASIC's

stack.

in

If

you

xxxxx

write:-

CALL DAS4

(D%(O),

MD%,

FLAG%)

3-9

PROGRAmG

you

will

mix

up the CALL routine, since it

as the mode number, the mode

2.

3.

parameters

(mode, data, errors)

The CALL routine expects its parameters variables and assumption. double precision) variable in the CALL pmeters, the routine

will

not function correctly.

CALL on the variable type,

computer! You

parameter list brackets

must

cannot

will

If

you slip

will

interpret

MD%

always

perform any arithmetic functions within the

write

up

of

be

written

and read and use a non-integer (real single

so

the

in

No

error checking

be

careful since you may crash the

CALL statement e.g:-

as

the

correct order:-

to

be

to

the variables on

is

data

D%(O)

etc..

integer

done

in

The

type

this

or

the

DAS-4

MANUAL

CALL DAS4

is illegal and will produce a syntax error.

4.

Apart from these restrictions, you can name the integer variables what you want, the names in

the examples are just convenient mnemonics. Strictly, you should declare the variables before

executing the CALL.

but array variables cannot

to

routine require multiple items

as the data variable

initial element

You can use some elegant techniques with

or output a whole series of data in a

a two or more dimension array, for example:-

You

cannot use constants

statement. The following is illegal:-

CALL DAS4

This must be programmed as:-

XXxlO xxx20 xxx30 CALL DAS4 (MD%, D%(O), FLAG%)

pass data

MD%

D%(O)

COKCX~~Y

(MD%

(7,2,

=7

=

If

you do not, the simple variables will

be

if

used as a CALL parameter. Many modes of the DAS4.BIN CALL

so

that the CALL routine can locate the whole

+

2,

D%(O)

for

any of the parameters in the CALL

FLAG%)

2

dimensioned by default

of

data

to

FOR.

*

8,

FLAG%)

be

passed in an array. For this reason, D%(O) is specified

the

CALL parameters. Let’s say we wanted to record

.

NEXT loop.

and

must

be

declared by default on execution,

be

dimensioned before the CALL

array

from the position

You

can dimension

your

of

D% array

its

as

xxx00 DIM D%(4,100)

SEG

=

xxxl0 DEF xxx20 FOR xxx30 CALL DAS4 xxx40

Likewise any of the other CALL parameters may

can name any number

dimension unchanged and for example could be used

arrays

I = 0

more elements

SG

to

100

(MD%,

D%(O,I), FLAG%)

I

of

different integer data arrays for output and input. It is

than

will

for

tagging data with time, date or other information.

be

integer array variables

be

used

by the CALL, unused elements

if

required, and you

O.K.

will

to

be

DAS-4

MANUAL

PROGRAMMING

MetraByte board. CALLS functions or modes use allow for only use each CALL for the whole program and save a BLOADing the DAS4.BIN driver (see EXO-BAS) proceed as follows (this program logs channels

has

chosen

This

makes the CALL structure

with

variable offsets

the

needs of modes

a

few elements. In the interests of clarity,

written

2

-

5

to

disk

xxl00 DIM D%(3)

XXllO

xx120 D%(O) = &H300 : D%(1) xx130 GOSUB 10000 'initialize xx140 xx150 D%(O)

xx160 GOSUB xx170 OPEN "MYF'ILE.DATt FOR OUTPUT AS xx180 TNOW = TIMER 'get system time (in seconds) XX190 xx200 GOSUB xx210 xx220

xx230

MD%

MD% PRINT

IF IF

to

use the Same CALL structure for selecting

and

number of parameters. One consequence of

all

of the data array D%(*).

4

&

out separately, but

every

INKEY$o""

TIMER > TNOW

10

=

0

=

1

=

2

:

D%(l)

10000

=

2

lo000

#1,

D%(0)*5/128

seconds):-

'set scan limits

'do

THEN CLOSE #l:END

easy

to

remember and helps

7 which use

you

can just as readily put the CALL

lot

of

lines of code, as

=

2

=

5

1

AD

conversion

+

10

THEN

'get next channel at

In

practice

all

four

elements, but most of the other modes

our

example programs use inline code with

'save

data

GOTO xx180 ELSE GOTO xx220

to

it

is dimensioned to

in

the

#1

to

disk

scaled

if

'finish

10

key pressed

second intervals

any

of the functions of the

avoid errors compared to

this

is

that not

D%(3)

into

one subroutine

following example. After

in

volts

all

to

10000

10010 10020 RETURN

CALL

IF

DAS4

FLAG%oO THEN ?"Error # ";FLAG%;"

(MD%,

D%(O), FLAG%)

'subroutine for

in

mode ";MD%:STOP

all

calls

3-11

PROGRAMMING

DAS-4

MANUAL

3.4

The following subsections give detail information and examples of in

EXAMPLES

all

10

modes. The modes

MODE

0

2

3

4

1

...

... Set multiplexer low

...

OF

THE USE

are

selected by the

FUNCTION

Initialize, input

&

check hardware.

Perform a single increment multiplexer address. conversion). Speed up to foreground.

Perfom an Conversions initiated by transferred to an integer array. Speed up to Operation - foreground.

Perform memory buffer area. Conversions initiated by an external input. Data transferred by intempt. Speed up to

an

3KHz.

DAS-4

N

conversion scan after trigger into a

Operation - background.

OF

THE CALL ROUTINE

MD%

A/D

parameter

base address, interrupt level

&

high scan limits. conversion. Return data and

in

(Programmed

200Hz,

conversion scan after trigger.

an

external input. Data is

the

use of the CALL routine

the CALL

Operation

as

-

3KHz.

follows:-

5

6

7

8

9

... ...

...

to

a

Analog trigger function similar

&

OP

slope)

4.

1-4.

(specify channel, level

Transfers data from memory buffer to

array

(used after mode

Return status. Reports next channel number to converted, whether interrupt is active interrupt level and remaining number of conversions in interrupt mode

Read digital inputs IP1-3.

Write digital

either

as

a whole block

4).

outputs

scope trigger

an

or

piece by piece

or

finished,

integer

be

3-12

DAS-4

MANUAL

PROGRAMMING:

MODE

0

3.5

Before

ADDRESS,

fail

(FLAG%

Calling mode straight after loading the initializing, run and list

On entry the following parameters should be assigned:-

MODE

using

to

provide

=

then:-

0

=

INITIALIZE

any other mode

of the

1,

DAS-4

this

information before accessing any other mode of the CALL, error flag

driver not initialized) will

0

need only

of

the

board and the hardware interrupt level that you intend to use.

be

done once in the initialization section of

DAS4.BIN

EXO.BAS

D%(O) D%(l)

=

&H300

=

2

D%(2)thru FLAG%

CALL

=

DAS4

and

D%(3)

X (value does not matter)

(MD%,

CALL

routine,

be

obtained and none of the other modes will execute.

routine. For examples of loading

you

EXOO.BAS.

'for example 'for example (interrupt level,

D%(O),

A

Note that specifying the fkst element of the array will pass

(VO

FLAG%)

must provide the YO location,

your

address)

2

thru

7)

(value does not matter)

all

other required

my

parameters.

or

BASE

If

program

usually

DAS4.BIN

you

and

On return the variables contain data as follows:-

MD%=O

D%(O)

The following error codes apply to mode

FLAG%

The standard 3FO),

the

VO

use

attempt

FLAG%

the

#11

Error

P.C.

expansion bus correspond to 2 thru

IBM

PC/AT

addresses below

to

assign

will occur

allows use of addresses between

an

variable.

thru

D%(3)

=

0

=2

=3

=

10

=

11

PC

or

PWT

256

(Hex

VO

address in the range

if

you

have specified a non-valid interrupt level. The available levels

allows use

(unchanged)

0:-

(no

error, (mode number out of range, (hardware failure) (base address out of range

(interrupt

of

100)

for

0

7.

0.k.) c0

or

>9)

c256

or

>1008)

level

<2

or

>7)

VO

addresses between

256

and

1008

internal devices, hence the driver

-

255

(Hex

0 - FF)

Certain of these levels may

512

and

1008

(Hex

100

-

3FO),

by

returning error code

be

in use

(Hex 200

all machines

will

flag

any

$10

on

the

by

other

-

in

3-13

PROGRAMMING: MODE

0

DAS-4

MANUAL

peripheral devices (especially level interrupt assignments is:-

-

Level Level Level Level Level Level

If

you do not have a particular device installed,

by DAS-4. The lower the level number, the higher the interrupt priority. Note that the interrupt

will not be enabled unless

not

Mode 0 performs several other initializing functions. Default scan limits of channels set. Mode

as a check on the presence and indicative

address

2

3

4

5

6

7

going to make use

0

also performs a simple readwrite test and a check on the busy signal from the

of

a hardware fault

specified

Reserved (but not

-

Serial

-

Serial

-

Printer

-

Always in use by disk drives

-

Printer

in

D%(O)

40

-

40

-

may

-

may be

you

of

interrupts any level

in

and the actual switch setting

6

used

used)

used

if

COW:

used

if COM1: installed.

be

used

by LPT2: if installed.

used

by LPT1: if installed.

enter

mode

function

the

DAS-4

of

4

the

by floppy

by Color Graphics adapter

installed.

it

which requires interrupts for

can

be

disk

drive). A list

is

safe

to assume that level is available for use

chosen e.g. D%(1)

of

operation.

=

2.

the standard

If you are

0

&

IBM

7

are

A/D

DAS-4

or more commonly a discrepancy between the base

hardware.

on

the board.

If

you obtain error

3,

it

is either

3-14

DAS-4

MANUAL

PROGRAMMING:

MODE

1

3.6

Mode 1 is used to set the scan limits by mode passed. D%(O) contains the lower 0

To illustrate the action

(commanded by modes channel incremented to 4. The next conversion would be performed on channel 4, data returned and the channel incremented

software counter

limit

including channels

If

error code

If

equal

perform continuous conversions

MODE

0.

This is done prior to performing conversions

are

0.k.

for you,

to repeat the sequence. Scanning of channels would always be stepped between and

you

specify the lower

4

as this is an illegal setup condition.

you

wish to perform continuous conversions on one channel, then set the low and high limits

to each other and the desired channel number e.g. setting D%(O)

1

=

SET

it

is not necessary

of

mode 1 assume we set

2,

in

the driver controlling the

3

and

6

as

3-4-5-6-3-4-5-6-3- etc.]

limit

MULTIPLEXER

of

limit

to

enter mode

3

or

4) would

to

5

etc. After the conversion on channel 6 has been performed,

follows:-

greater than the higher limit i.e. D%(O) > D%(

on

channel

SCAN

the multiplexer to other than the default limits provided

in

modes

and D%(l) the higher limit.

1.

D%(O)

be

performed on channel

mu

1.

=

3

and D%(1) = 6. The frst conversion

will

automatically re-load

LIMITS

2,

3

&

4.

Two limits are

If

the default limits of mode

3,

data

returned

to

the

start

1)

you will receive

=

1

and D%(l)

=

and the

the

of scan

1

would

Note that after exit from mode

On entry the following parameters should be initialized:-

MD%=1 (mode number)

=

0

thru

D%(O)

=

D%(l) D%(2

FLAG%

then:-

On return the variables contain data as

h4D%=1 (unchanged)

D%(O

The following error codes apply

D%(C)

thru

=

CALL DAS4

thru

7

3)

X

3)

+h

1,

the starting channel

(lower scan limit)

7

(upper scan limit) (value does not matter) (value does not matter)

(MD%,

to

D%(O),

follows:-

(unchanged)

mode

1:-

will

FLAG%)

always

be

D%{O),

the

lower limit.

PROGRAMMING:

MODE

1

DAS-4

MANUAL

FLAG%

An

example

examples using the

of

the use

=

0

=1

=2

=4

=

10

=

11

of

mode 1 will

A/D

converter.

(no

error,

0.k.)

(driver not (mode

(if

limits reverse order,

(if lower channel

(if

upper channel limit

be

initialized)

number

found

out

in

of range, # or

D%(O)

limit

D%(O) D%(

1)

EX2.BAS

as

>9)

>

D%il))

c0

or

<O

or

well

>7)

as

several of the other

3-16

DAS-4

MANUAL

PROGRAMMING:

MODE

2

3.7

INCREMENT

Mode 2 performs one

incremented after the conversion through software routines

follows:-

Data is transferred to corresponding to -Full Scale of -5v and +127 corresponding to +Full Scale of

volts corresponds to zero bits. This minimizes processing of the data after

D%(l)

ignored as required. The

in channel

On

MODE

2

-

DO

ONE

AID

CONVERSION

MUX

A/D

conversion by software command. The

D%(O)

D%(l)

contains the channel from which the data is derived.

A/D

will perform conversions on channels

mode

entry

1.

If

mode 1 has not been entered prior to mode

0

and channel

the

following parameters

-

A/D

data (-128 to

-

Channel number

D%(O)

7.

in

should

+127

bits)

2’s

compliment form (standard integer)

in

accordance

be

initialized:-

AND

mux

in

the driver. Data is

exit

This

information

with

the

scan

2,

conversions will cycle between

is automatically

returned

with

-128

4.961

from

limit

volts. Zero

the

CALL.

can

be

used

conditions set

as

bits

or

MD%=2

D%(O

FLAG%

then:-

CALL

On return the variables contain data as follows:-

m%=2

D%(O)

D%(l) D%(2

The

following error codes apply to mode

FLAG%

thru

3) = X

=

X

DAS4 (MD%,

=

AD

data

=

Channel number

thru

3)

=

0

=1

=2

=3

(mode number)

(value does not matter) (value does not matter)

D%(O),

FLAG%)

(unchanged)

(-128

of

data

(unchanged)

2:-

(no error, (driver not initialized) (mode number out

(No

EOC

indicative

to

+127

bits)

(0

-

7)

0.k.)

from

AD,

of

hardware failure)

of

range,

time out

<O

or

>9>

3-17

PROGRAMMING:

An

example of the use

If

you

wish

to

becomes milliseconds per line conversions/sec. on a standard

limited

MODE

of

mode

perform a series of

by

the program execution time which for interpreted B,ASIC is slow (several

of

code). A tight

2

IBM

will

P.C.

be

found in

A/D

conversions

loop

(4.77MHz

EX2.BAS.

such

as

clock):-

using

the one below

mode

2,

DAS-4

be

aware that

will

perform around 200

MANUAL

the

speed

xxx10

xxx20

xxx30

-40

xxx50

xxx60

If

this is compiled using the BASIC compiler, a conversion rate of about

be

obtained.

DIM

X%(lOOOO)

MD%

FOR

CALL

=

I%

DAS4

X%(I%)

etc.

2

=

0

=

D%(O)

TO

10000

(MD%,

D%(O), FLAG%)

4000

samples/sec. will

3-18

DAS-4 I"UAL

PROGRAMMING:

MODE

3

3.8

MODE

3

=

DO

N

A/D CONVERSIONS DIRECT

TO

ARRAY

Mode 3 performs may be any number of conversions up dimension an integer array with 32,767 elements and leave any workspace for the program

(30,000

transfers as a "foreground" operation, have been completed. being gathered your BASIC program. mode in gather the data as a "background" operation collect

The in

and the upper scan

In mode

although this mode

holding

until the full conversion count even if IP1

it

A/D

mode

is a more practical limit). Since the CPU is performing the

this

at the same time.

will perform conversions on channels in accordance with the scan

1.

If

3,

each

IP1

N

AD

conversions and transfers

to

exit

from the CALL

To

provide

in

mode 3

case.

If

mode 1 has not been entered prior

limit

A/D

low, as soon as IP1 goes high

will

You

you

do

will be channel 7.

conversion is initiated by a positive edge

does

not make

an

escape route, hitting any key on the keyboard while

abandon further conversions and produce an immediate return to

will

receive

not want to wait for data to

error

use

of hardware interrupts. Triggering may

A/D

goes

data

directly into a BASIC integer

32,767 although

code

5

as

so

that your program is able to process data and

to

mode

conversions will commence and

low again.

in

practice it is impossible to

A/D

polling and data

will

not

occur

a warning that you have aborted the

be

collected, mode 4 can be used to

3,

conversions will

on

the

until

all

limit

start

interrupt input

be

my.

conversions

conditions set

on

channel

(pin

held

will

continue

N

data

is

24)

off

by

0

entry

On

then:-

On retum the variables contain data as follows:-

the following parameters should be initialized:-

MD%

D%(O)

D%(l)

D%(2 FLAG%

MD%=3 (unchanged) D%(O ARRAY%(M)

ARRAY%(M+l) ARRAY%(M+2)

=

3

(mode number)

=

VARPTR(ARRAY%(M)) - array pointer

be

Conversions may position

=

Number of conversions required (Word count).

Range 1 to N where

thru

3)

CALL DAS4 (MD%, D%(O), FLAG%)

thru

3)

in

an

array or at the start

-

(value does not matter)

-

(value

(unchanged)

= = =

loaded starting at the M'th.

N-1

c=

does

1st. data word 2nd. data word 3rd. data word

if

M

may dimension

not matter)

=

0.

PROGRAMMING:

...

etc.

MODE

3

DAS-4

MANUAL

The following error codes apply to mode

FLAG%

=

0

=1

=2

=3

=5

=

11

An

example

A

number of precautions apply to the reliable use of mode 3. First you must dimension a

receiving array that has at least

D%(l).

conversions than the array overwritten which may destroy descriptors and other variable data and cause strange effects as a result.

Second, after assigning the pointer to the receiving array, do not introduce variables before entering the

No

Do

of

checks

not

ovemcn

the use

are

xxxl0 xxx20 xxx30

-40

xxx50

of

mode

3

will

as many elements

made by the

will

the

array

limits.

CALL.

DIM

D%(3),

MD%

D%(O)

D%(

=

3

=

VARPTR(X%(O))

1)

=

1000

CALL DAS4

hold.

3:-

(no error, 0.k.) (driver not initidized) (mode number out (hardware error (mode aborted by keyboard) (number of conversions

be

found

CALL

If

For example,

in

routine

you do, some

X%(999)

(MD%,

D%(O), FLAG%)

of

range,

-

A/D

not converting)

EX3.BAS.

as

the number of conversions specified

on

of

this

is

0.K.:-

'declare 'mode 'pointer to array 'number

D%(

whether

the data area

D%(*), X%(*)

#

c0

or

>9)

1)cO

or >32767)

you

are performing more

of conversions

of

BASIC

any

in

will

be

new simple

But this will cause a problem:-

xxxl0

-20

xxx30

xxx40

-50

xxx60

The problem arises because of the way memory above the data area for simple (non-array) variables which program storage area. If you introduce a simple variable that has not been used before, makes room for this variable by re-locating all the array variables upwards pointer (using and then the routine writes data to the old array location causing strange effects.

ALSO

number of trigger pulses

these

up. Conversion rates in excess of

computer (mainly the timer interrupt) may divert the

data from the

NOTE

conditions

To

abort mode

VARPTR)

CALL

that exit

are

A/D

DIM D%(3), X%(999) MD%

=

3

D%(O) = VARPTR(X%(O)) D%(

1)

=

lo00 NEW-VARIABLE = X CALL DAS4

(MD%,

D%(O), FLAG%)

BASIC

is assigned to the receiving array before a new variable is introduced

is entered, the actual location

from

mode 3

to

perform the desired number of conversions have been supplied. If

not met, your computer may give the erroneous appearance of being hung

3,

hit any key on

2000

for several

hundred

cannot

the

samples/sec

microseconds, data may

occur until

keyboard.

'declare 'mode 'pointer to array 'number of conversions

'new variable

stores array variables. They are located

of

the array will have changed,

IP1

are

attainable

CPU

D%(*),

#

has been taken high

in

away from attending to transferring

be

X%(*)

in

turn

this mode.

lost above

is located above the

in

memory.

and

the

and

a sufficient

As

interrupts in the

3000

samples/sec.

in

BASIC

If

the

CALL

3-20

DAS-4

MANUAL

PROGRAMMING:

MODE

4

3.9

MODE

4

=

DO N A/D

CONVERSIONS

AND

TRANSFER TO MEMORY ON INTERRUPT

Mode 4 performs mode. Each time an interrupt is invoked by a positive edge on the Intermpt handler performs an AD conversion, moves the data and increments the multiplexer ready for the next interrupt. The handler keeps track of the total number of conversions performed. When the number reaches interrupts are disabled continuously to the same segment of memory once mode user may be running (although they should not interfere either with the location of the

DAS4.BIN

About

taking

operations.

To

return

mode interrupt operation initiated by mode descriptions of the features of these other modes, see

A/D

The

in

mode

and the upper scan

4

driver or the

3000

place

data to a BASIC integer array when mode

6.

To

will

1.

If

N

A/D

conversions through a special interrupt handler that

to

a memory buffer area (up to

N,

as specified by

if

in the non-recycle mode

if

has enabled intenupts, conversions continue regardless of what other programs the

A/D

data area). For

samples/sec.

in

the background, you may notice a significant reduction in speed of foreground

assess the progress

perform conversions on channels in accordance with the scan limit conditions set

mode 1 has not been entered prior to mode

limit

are

will

possible

of

be

channel

in

an operation

4,

7.

this

mode 4 although at

re-enter mode 4 but with

(D%(3)=0),

D%(3)

reason it

4

is

initiated

the

or the process is repeated

specifies the re-cycle mode. Note that

is

termed a background opepttion.

this

speed

operating or has finished operation, use

by mode

following sections.

4,

conversions

4,

use mode

is

installed by this

In

@in

64K

so

much processing is

7.

To

D%(2)

will

=

start

0.

on

24),

the

bytes)

D%(O),

abort

For detail

channel

an

0

The

A/D

mggering occurs indirectly through the intempt handler. On a

8088 based

start

and the internal time of day interrupt on level low will hold off triggering. microseconds after which its subsequent state keyboard will

as

a reminder that the keyboard initiated conversions.

On entry

PC,

there is typically an

of

A/D

conversion.

also

start

the following parameters should

MD%

D%(O)

D%(l)

=

4

(mode number)

=

Number of conversions required (Word count).

Range Note: BASIC only provides signed integers, data is passed as integer (see Appendix

=

Se,grnent on paragraph

&H7000

Be

data buffer (always outside BASIC workspace)

D%(2)

-

Enables/disables intempt:-

This

conversions while

-32768

of

would start loading

sure to choose

80

microsecond latency between generation

latency varies according

To

start

to

+32767

memory to receive data. Segments

(16

bit) boundaries e.g.

an

0.

P1

triggering

IP1

is held low, in this case error code 5 is produced

initialized:-

be

C).

e.g.

empty area

acts as a

IP1

will

have no effect. Hitting any key of the

-1

corresponds to

A/D

of

4.77

to

other interrupt activity especially

start

gate for the operation, holding

should

be

taken high for at least

65,535

conversions.

are

D%(l)

data at

memory for a

=

448K.

MHz

standard

of

the interrupt

an

unsigned

IP1

100

3-21

PROGRAMMING:

MODE

4

DAS-4

MANUAL

then:-

D%(2)=1:

Enables interrupt. Interrupts

automatically disable when conversion count is reached in nonrecycle mode.

D%(2)=0:

Disables intempt. Used to abort

active intempt interrupts when operating in the recycle mode.

D%(3) - Single cycle/Re-cycle operation:-

D%(3)

D%(3)=

=

0

:

One cycle. After completion of the

of

number interrupts operation status

1

:

Re-cycle.

conversions specified,

are

disabled,

to

In

this case data continuously written to the same memory.

D%(O)

corresponds to the

memory "buffer" length. The status

of

the operation is

stopped by re-entry

FLAG%

=

X

CALL DAS4

(value does not matter)

(MD%,

D%(O),

FLAG%)

or

stop further

setting

zero.

1

=

active until

with

D%(2)

will

=

the

an

the

is

0.

On return the variables contain data as follows:-

MD%=4

D%(O

The following

FLAG%

thru

error

3)

codes apply

=

=1

=2

=5

= =

An

example of

reliable use of mode

the

use of mode 4,6

4.

On completion of

intempt mask register is disabled and the tri-state interrupt drivers of the

(unchanged) (unchanged)

0

12

13

to

mode

4:-

(no error, 0.k.) (driver not initialized) (mode number out

(if

mode initiated by keyboard)

(if

D%(2) neither 0 or

(if

D%(3)

&

7

neither 0 or

will be found

an

interrupt operation,

of

range,

1)

in

EX4.BAS.

<O

or

>9)

Several details apply to the

the

selected level

DAS-4

are

of

the 8259

placed

in

the high impedance state, also the previous interrupt vectors used by this level are restored. This allows more long as they do the maximum data area available is

is

area using mode possible

not

to

than

one hardware device, or multiple

so

sequentially. Since the segment registers

64K

(a page) for

in

use by your program or altered by subsequent operations. Data may

6

during or after the operation of mode 6 and

re-write

the interrupt handler

to

use several segments

DAS-4's

are

65,536

this

to use the same intempt level as

not incremented by the handler,

conversions. Be sure that

will not alter the memory.

of

main or extended memory

your

be

retrieved

data

It

for data storage.

is

3-22

DAS-4

MANUAL

PROGRAMMING:

MODE

5

3.10

Mode 5 provides an analog trigger function similar to an oscilloscope trigger. It is sometimes useful provides channel, and you may set the level and slope for triggering.

The main use for mode loop until the specified analog trigger conditions wait loop indefinitely hitting any key which

Parameters trigger level and the trigger direction (slope).

be one of the scanned channels i.e. within the scan limits and carrying one signals, or a separate channel outside the scanned channels level at which niggering occurs is set by direction of triggering or slope is controlled by level will exceeds trigger signal becomes less than

On entry the following variables should be initialized:-

MODE

to

wait for a voltage to reach a certain level before starting to gather

this

capability. Any of the analog input channels may

D%(O)

be

+2v and

+2v,

alternatively

5

will

thru

if

=

ANALOG TRIGGER

5

is

in

front of any of the other

are

if

the trigger conditions

return you to the calling program.

D%(2)

control the mggering and select the trigger channel number, the

D%(1)

=

0

(positive slope) triggering will take place when the signal

if

D%(2)

+2V.

=

1

(negative slope) triggering would take place when the

are

D%(O)

in

D%(2),

not fulfilled, you can also

specifies

bits, (valid range of

FUNCTION

data

acquisition modes

met. Since

the

used

for instance if

be

it

is possible to

trigger channel number.

only for triggering. The voltage

data

and

mode

designated as a trigger

as

a gating or wait

get

stuck

exit

mode 5 by

of

the measured

-128

to

+127

bits). The

D%(l)

=

51

the trigger

in

It

5

the

may

.-

.

MD%=5

D%(O) = Channel number

=

D%(l) D%(2) = Slope

D%(3) FLAG%

then:-

CALL

On return the variables contain data as follows:-

D%(O

The following error codes apply to mode

FLAG%

Trigger level

(0

=

positive,

-

(value does not matter)

-

(value does not matter)

DAS4 (MD%, D%(O), FLAG%)

thru

3)

- unchanged

=

0

=1 (driver

=2

=5

(0

-

7)

(-128

to

+127

1

=

negative)

5:-

(no

error,

(mode number out

(if

exit aborted by keyboard)

0.k.)

not

bits)

initialized)

of

range,

<o

or

>9)

3-23

PROGRAMMING:

For

an

example

of

the use

MODE

= =

=

10

11

12

of

5

mode

(trigger channel (trigger channel level (trigger slope

5,

see

EX5.BAS.

data

D%(O)

D%(1) c-128

D%(2)

neither 0 or

#

or

>7)

or

DAS-4

>127)

1)

MANUAL

3-24

DAS-4

MANUAL

PROGRAMMING:

MODE

6

3.11

MODE

6

TRANSFER

DATA

FROM MEMORY

TO

ARRAY

Mode 6 transfers data from any segment of memory to integer array variables in BASIC

It

is

workspace. the form of single bytes of

6

Mode array that beginning element. number of the conversion (segment offset) buffer area is move 1000 conversions, starting at the 1OO’th element in

In

64Kbytes of data directly BASIC could not provide enough storage area

same effect

functions

you

D%(

the buffer:-

this way we can move data piece by piece and analyze it. Note that we could not handle

used following a mode 4 operation. Data in memory derived

AD

data corresponding

as

follows. D%(O) provides the location of the starting element

wish

to

transfer

of

the array

1)

provides the number of conversions or data bytes

assumed

D%(O)

D%(l) D%(2)

as

mode 6 using DEF

,

to be the same

=

VARPTR(X%(lOO))

=

1000

=

20000

to

e.g.

D%(O)

X%(O),

in

whereas D%(O) = VARPTR(X%(N))

to

as

that specified in mode

an integer array, as integers take 2 bytes of storage (one word) and

SEG’s

and

to

each conversion.

=

VARPTR(X%(O)) would

start

transferring fiom. The segment

4.

in

the area and the

(try

DIM

X%(65535)).

PEEK’S

in

a loop but

to

mnsfer, and D%(2) sets the

By

way

We could accomplish the

it

would

from

mode 4 is in

of

the integer

start

moving

would start at the N’th

of

an example, let’s

20,OOO’th

be

a lot slower.

data

to the

area

of the

conversion

you

must

be

Note that

1:

Do

or

performed

corrupt BASIC workspace and cause strange effects.

2: There

garbage from a source segment that does not contain

A/D

condition.

On entry the following parameters should be assigned:-

MD% = 6 D%(O)

D%(l)

D%(2)

careful about the transfer parameters. In particular-

not transfer more words than

overrun the end of the array. No checking

to

detect this condition which

is

nothing to prevent

A/D

data

or

from overrunning the end

data. No checking is

(mode number)

=

VARPTR(X%(N)) - (array locator)

=

Number

=

Starting conversion number

of

transfers (cannot exceed

performed

an

you

array

transfening

to

will

hold

is

will

of

detect this

32,767)

3-25

PROGRAMMING:

D%(3) - (value does not matter) FLAG% - (value does not matter)

then:-

CALL DAS4

MODE

(MD%,

6

D%(O),

FLAG%)

DAS-4

MANUAL

On return the variables contain data

MD%=6

D%(O

The following error codes apply to mode 6:-

FLAG%

thru

3) - unchanged

=

0

=1

=2

=

11

For

an

example of the use of mode

Once data acquisition has been option to retrieve the data. This is excellent for graphics, "digital oscilloscope" and continuous write to

disk

Note that

immediately before the

assignment

I

(see mode

of

mode

applications.

had not been declared prior

4,

a foreground program can

it

is advisable

D%(O) = VARPTR(X%(N))

will

dynamically relocate the arrays and upset operation

3

for a fuller description of this problem):-

to

make the assignment:-

CALL

to

as

follows:-

(no error, 0.k.) (driver not initialized) (mode number out of range, (number

6,

see

set

up

statement,

line xxx10, then the following sequence would cause a problem

of

transfers,

EX4.BAS.

as

a constant background operation using the recycle

be

processing the data as

as

declaring a new simple variable after

D%(

<O

or

1)=0

or >32767)

of

>9)

it

is acquired using mode

making

this mode.

If

the variable

this

6

3-26

xu10

xxx20

xxx30

D%(O) = VARPTR(X%(O))

1=3

CALL DAS4 &ID%, D%(O), FLAG%)

7

DAS-4

3.12

Mode 7 returns acquisition using mode background operation.

On entry the following parameters should

MANUAL

MODE 7

MD%

D%(O FLAG% - (value does not matter)

then:-

status

=

7

thru

CALL

-

READ

data which is especially useful when performing background

4.

It

can inform a foreground operation about the progress

(mode number)

3)

-

(value does

DAS4

(MD%,

STATUS

D%(O),

be

initialized:-

not

matter)

FLAG%)

PROGRAMMING:

MODE

data

of

7

a

On return the variables contain data as follows:-

MD%

D%(O)

D%(l) = Status of interrupt operation:-

D%(2) = Selected interrupt level

D%(3) = Remaining number of conversisns to

The following error codes apply

FLAG%

For

an

example

of

=7

(unchanged)

=

Channel number

’

0

1

(corresponds to setting of mode

to

=

0

=1

=2

the

use

of

mode

of

next channel to

-

Done(finished)

-

Active (in progress)

mode

7,

7:-

(no error, (driver not initialized) (mode number out of range,

see EX4.BAS.

0.k.)

be

0)

converted

be

done

<O

or

>9)

3-27

PROGRAMMING

MODE

8

DAS-4

MANUAL

3.13

Mode 8 allows you to read the state and 7 corresponding to

On entry the following parameters should

On return the variables contain data as follows:-

The following error codes apply to mode

then:-

MODE

MD%=8

D%(O

FLAG%

CALL DAS4

MD%=8

D%(O)

D%( 1 thru

thru

conrains input data (range

8

-

READ

alI

combinations

3)

=X

3) - unchanged

-

(ID%,

DIGITAL

of

digital inputs

of

the 3 input bits, IP1-3.

be

value

D%(O),

does does

FLAG%)

8:-

initialized:-

0

INPUTS

IP1-3.

not matter

-

7)

IPI-3

Data

returned can range between

0

For

an

example

FLAG%

of

digital

=

0

=1

=2

input using mode

(no error,

(driver not initialized) (mode number out

8,

0.k.)

see

EX8.BAS.

of

range,

<O

or

>9)

DAS-4

MANUAL

PROGRAMMLVG:

MODE

9

3.14

Mode 9 is used to write digital data to

in

the range

On

then:-

On return the variables contain data as follows:-

The following error codes apply to mode

MODE

0

-

entry the following parameters should be assigned:-

MD%=9

D%(O)

D%(1

FLAG% CALL

MD%=9

D%(O

9

-

WRITE

15

and

if

not

=

output data (range

thru

3) - value does not matter

=

X

DAS4 (MD%,

thru

3)

DIGITAL

the 4

bit output port,

an

error

exit

(error

0-15)

-

value does not matter

D%(O),

-

unchanged

-

unchanged

FLAG%)

9:-

#

OUTPUT

10)

occurs.

OPI-4

OP1-4..Output

data is checked to

be

FLAG%

For an example of

=

=1

=2

=

digital

output using mode

0

10

(no error, (driver not initialized) (mode number out

(Q%(O),

0.k.)

output data

9,

see

EX9.BAS.

of

c0

range,

or

>15)

<O

or

>9)

3-29

PROGRAMMING

DAS-4

I"UAL

3.15

If for any reason the FLAG% variable is returned non-zero, then an error has occurred input of data

be

taken in the FLAG% variable. The only exception to this rule is error installation error) to

be

Following

SUMMARY

to

the CALL routine. Checking of data occurs first

if

an

error condition exists. An immediate return will

,

where an attempt

a problem

ERROR

0

1

2

3

so

that other

is

a

list of error codes:-

OF

modes

No

error, operation successful.

Driver not initialized. Using another mode before initializing with mode

Mode number out

less than Hardware enor.

address,

ERROR

will

be

made to initialize the hardware even if there appears

may possibly

FAULT

of

0

or

greater than

Board

not

in computer

CQDES

be

run to diagnose the problem.

range. Specifying

9.

not at specified

or

A/D faulty.

in

the routine and

take

place

0.

MD%

VO

no

action will

with

the error specified

#3

(hardware failure or

in

the

4

5

10+N

Error

detection after the CALL routine is easily implemented:-

xxxl0 CALL xxx20 IF FLAG%

or:-

(xxx20 IF FLAG%

Scan limits in wrong order (mode scan

low

limit

>

scan high limit Mode aborted by keyboard (modes Error

in

range of

Note:- Errors

by data range errors D%(2), the specific error, number.

DAS4

(MD%,

o

0

<>

0

D%(N)

10,

11,

12,

D%(3).

D%(O), FLAG%)

THEN

GOSUB yyyyy

PRIhT

13

are caused

FGi

look

"Error

1)

3,4

&

in

D%(O),

a description

up under mode

";FLAG%

D%(

5)

l),

of

:

STOP)

...

yyyyy REM: Error handling subroutine

...

Lzzz

This is useful while debugging a new program, or with a suitable error handling subroutine, can

be

left permanently in the program. See EXO-BAS for an example of

routine.

RETURN

an

error capturing

3-30

DAS-4

I"Ua

PROGRAMMING

3.16

PROGRAMMING EXAMPLES

MODES

A

number of program examples are included

include:-

1:

2:

3:

4:

5:

6:

EXO.BAS

EXOO.BAS

EX2.BAS

EX3.BAS

EX4.BAS

EX5.BAS

-

Example of loading the

an

at initializing

Example by contracting BASIC's workspace and initializing with mode

Using mode 2 (single conversion) for

AD,

Example of doing to an integer array (modes

Example of doing interrupts (modes

Example of using

absolute memory location and

also

FOR

on

the floppy disk accompanying

DAS4.BIN

with

mode

of

loading the DAS4.BIN driver

shows use

0.

of

mode

A/D

conversions direct

A/D

conversions using

1,4,6

A/D

trigger mode

&

1

7).

1.

&

3).

THE

driver

5.

DRIVER

this

manual. They

7:

8:

Since provide provide the basis for

3.17

In addition

2:

3:

4:

EX8.BAS EX9.BAS

all

of these programs are in BASIC and are heavily commented, they are readily listed to

a

better

understanding of how

OTHER PROGRAMS

to

the examples above, the DAS-4 distribution

1:

DAS4.BIN DAS4.0BJ DAS4.ASM

HOWTO.BIN

-

your

Example of Example of

own programs.

-

digital digital

to

program DAS-4. They can also

The DAS-4 driver routine The object file The DAS4.BIN assembly source listing. Use

DAS4.ASM word processor.

Enter TYPE HOWTO.BIN to find out how to modify and re-assemble DASABIN

of

interest to assembly language programmers)

input mode

output mode 9.

AND

of

DAS-4 for compilers

to

display this or load into your favorite

8.

UTILITIES

disks

includes:-

from

DAS4.ASM (mainly

be

edited

and adapted to

TYPE

5:

1NSTALL.EXE

-

Base address switch setting aid.

3-3

1

PROGRAMMING

DAS-4

MANUAL

6:

7: CAL.BAS

8:

9:

From time to documented for the latest information.

3.1

STRIP.EXE

STRIP.

CAL.EXE LOG.BAS

README.DOC - ASCII text

ASSEMBLY LANGUAGE PROGRAMS AND

8

he,

in

this

B AS

MetraByte may add other utilities and examples

manual. For explanations enter

-

I

-

Example

compiled from BASIC source STRIP.BAS.

Calibration and test program (compiled version)

A simple low speed data logging program that writes

an ASCII

etc.)

additional undocumented programs.

of

disk

a

"real

file

time"

file

TYPE

strip chart program

(suitable for import to Lotus

providing information

to

README.DOC after the DOS prompt

1-2-3

on

any

the disk that are not

CALLS IN OTHER LANGUAGES

To facilitate the use object code file DAS4.0BJ is provided. This was assembled using the Assembler and may the routine's public name is DAS4 The fully commented source code and listings of the CALL routines disk in file DASAASM. Simply run this through the Macro Assembler (MASM DAS4) to

generate a

propmmers who

customizing routines DAS4.BlN file is described

prompt (pressing Ctrl-PrtScreen will give you a hard copy

in

BASIC or BASIC COMPILER, you most probably will never need to refer to the source

listing.

full

of

the

I/O

driver CALL routines

be

linked

listing (DAS4.LST). This material

will

to

to other object modules from compilers etc. When using the linker,

(see

next section concerning use of BASIC COMPILER}.

find the source listing an excellent starting point for adapting or

special requirements. The process for generating a BLOADable

in HOWT.O.BIN, simply enter TYPE HOWTO.BIN from the DOS

in

other languages e.g. C etc. the assembly

IBM

or Microsoft Macro

will

be

found on the utility

is

mainly of interest to assembly language

too).

If

your pro-grammhg is entirely

3.19

A

NOTE

ON

EXECUTION

TIMES

-

COMPILED

BASIC

The throughput of the DAS-4 fundamental limitation is the speed and the sample/hold which takes

could perform conversions at 33KHz and this can in fact be accomplished with a tight assembly language loop. The

are

and

functions

operations

reduce your overall throughput.

3-32

much slower, about 3KHz is the maximum speed. Once inside the CALL, all the

run

in

various

at assembly language rates and are

your

pro,pm processing the data between CALLS may produce bottlenecks and

AD conversion modes

A/D

converter is a function

of

the

AD

which

10

microseconds or less to settle. This would indicate that

has

a conversion time of 20 microseconds

of

the driver involve a lot

not

affected by the BASIC interpreter, but other

of

many interactions but the

of

"housekeeping"

you

DAS-4

MANUAL

PROGRAMMING

One quick

IBM

BASIC program the significance of the DAS4

DAS4 is

fix

to improve the speed of an interpreted BASIC program is to compile

Basic Compiler, Microsoft Basic Compiler

in

xxxl0 CALL DAS4

not

interpreted by the compiler as a variable. It becomes the public name of the

@ID%,

D%(O),

it

using the

or

Microsoft Quick Basis. When

you

compile a

the CALL statement is no longer the same:-

FLAG%)

subroutine that you wish to call. Before compiling your program, remove lines that BLOAD the

and

DAS4.BIN routine

all DEF SEG statements that control the location

not required as the linker

will

locate the DAS4 routine in memory automatically. After compiling

of

the routine. These are

your program, run the linking session as follows:-

A>

LINK

is

DAS4.0BJ performance of compiling a program

This

is

a

real

on

time

yourprog.obj + das4.obj

your distribution disk for this purpose. An example of the effect on

is

supplied in the programs STRIP.BAS and STFUP.EXE.

"stxip chart" emulating program. The BASIC interpreter

form,

STRIP.BAS, is

extremely slow, but when compiled (STRIP-EXE) using the Microsoft Quick Basic compiler

speeds up

a point of being able to display about 30 points/second and give

an

effective real

to

time display.

3.20

MULTIPLE

DAS-4's

IN ONE

SYSTEM

What

if

you wish

to

operate more than one DAS-4

in

a computer?

DAS-4 must have a different base address and if interrupts are used,

if

interrupt level, or

a time. Each board must also

DAS4.BIN routine

the

Now

CALL appropriate to each

on a common level, each board's intempt can only

be

at

different locations

xxxl0 DEF SEG

xxx20

xxx30 SG2

BLOAD "DAS4.BIN",O

=

SG1+ 2048/16

xxx40 DEF SEG

xxx50

xxx60

BLOAD "DAS4.BIN',O

SG3 = SG2 + 2048/16

assigned its

=

SG1

=

SG2

board

own

in

memory:-

can

CALL routine.

'allow 2K for each routine

'etc. for other boards

be

entered

as

To

required. Note that each CALL

preceded by a DEF SEG appropriate to that board:-

yyy10

yyy20 yyy30 DEF SEG yyy40 CALL DAS4

DEF SEG = SG1

CALL

DAS4

=

(MD%,

SG2

(MD%,

X%,

FLAG%) FLAG%)

'etc.

2.

Microsoft

and

Quick

Basic

are

registered

trademarks

of

rhe

Microsoft

Corporation.

10700

Nonbup

Way,

To

avoid conflicts, each

be

connected to a different

be

enabled

do this

Box

97200,

in

turn, one at

start

by loading the

Belle~~.

WA.

is

98009

DAS-4

MANUAL

APPLICATIONS

Section

A P P

4.1

There are single ended between the channel (DIG.COM.) as this is intended signals and may differ is very important to obtain consistent noise inadvertent for all analog signal few milliamps. The seven identical low level ground inputs have been positioned connector helps

C.

multiplexer used on the channel and transient overloads of several hundred volts. desirable characteristics, a "break before make" action to prevent shorts between channels while

switching, and signal shorts when your computer is off.

CHANNEL

are

8

analog input channels

i.e.

ground

so

that they

to

prevent

thus presenting

cross

all

INPUTS

on

they

share

Hi

from

loops when using single ended connections. The low level grounds are used

returns

lie

talk.

a

high

DAS-4

channel switches

a common low level ground. Input voltages should

and any

as

a heavy current

the low level ground by many millivolts. Correct use of the grounds

and when used correctly should

between the analog channel inputs

The input current of each channel input impedance to the signal. Also the

is designed to withstand continuous overloads

LI

CAT1

DAS-4.

L.L.

turn

Each has an input range of -5.000~ to +4.961v and

Gnd.

off when the power is

4

0

N

S

Do

not return inputs to the digital common

return

free

measurements as

for power supplies and digital logic

it

is easy to introduce

only

carry signal currents less than a

in

the flat connecting cable, this

is

about 100 nanoamps at

508A

This

multiplexer has

off

thus preventing signal to

solid state channel

of

+/-

32v on each

be

two

applied

in

the

25

deg.

other

0

-

7

Channels are numbered control register byte. The current channel that the multiplexer is set to can

three

reading the of the mode 1 is

and initializing (mode

Line

4,

CALL

not specified scanning

xxxl0 xxx20

20

enables scanning between channels

5

-

2,

3,4,5

-50

xxx60 xxx70 xxx80 PRINT USING "Channel xxx90

lower bits of the status register. The

will

automatically increment

0)

MD%

CALL DAS4

MD%

FOR

CALL

-

2

etc.

=

I

=

(MD%, D%(O),

I

and the required channel is selected by the

A/D

convert routines of modes

the

multiplexer within the limits set by mode

will

default to the full range

DAS4.BIN

1 : D%(O)

(MD%,

2

1 TO

100

would be:-

=

2

:

D%(l)

D%(O),

FLAG%)

##

=

5

FLAG%)

2

and

5,

=

####";D%(

so

the sequence would

l);D%(O)

0

-

7.

A typical set up after loading

three

be

lower bits of the

be

determined by

2,

3

and

1.

2,

3,4,

5

-

2,

4-

4

If

3,

1

APPLICATIONS

DAS-4

MANUAL

INPUT

COMMON

4.2

Voltages

be

MEASURING

in

the range +/-5v may be directly applied to the analog

VOLTAGE

attenuated, a simple resistive divider should

be

adequate

as

shown in

inputs.

Fig.

Xgher voltages should

4.1.

Single ended inputs have a common ground return which is connected to the ground (case)

If

you

are

computer.

be

will

no problem but

measuring a signal which is floating

if

your signal source is also connected to ground, then there is the

potential for a ground loop which may cause an error or noise

this

ways to avoid

complication, some of the solutions are shown

these methods provide you with a differential input which allows

differences

in

ground potential between your computer

HNY ANALOG

INPUT

....

tc.

OPTIONAL

.

RY

---**---.

i

FILTER CAPACITOR

f

@

1

6TTENUATION

(Rx + Ry)

=

FIG.

4.1

RY

SIMPLE INPUT ATTENUHTGR

+L.L. GND.

i.e.

has no connection to ground, there

in

your readings. There are several

in

Figs.

4.2,4.3 & 4.4.

you

to reject any small

and

signal source.

TYPICAL VALUES KEEP

TO DAS-4 ATTENUATION

t

I

d

RX

x2

x

x x

LOW AROUND

10 120

1000

of

the

All

of

1 - 10K

-

RY

10K 90K 99K 1K

999K 1K

-

RX

1

OK

1

OK

DIFFERENTIAL

INPUT

The circuit of Fig.

set by

be

gain

the

too low for some applications.

or attenuation. This circuit

and a full description

3.

See

for

instance

I

FIG.

4.2

is

the least expensive, but has the drawback of having an

SIMPLE DIFFERENTIAL RMPLIFIER

input resistors. This may

is

can

be

found

"Operational

Amplitiers

-

Dcsign

UOLTFIGE

be

quite large, in the lOKohm to lOOKohm region,

As

an added benefit, the resistors may be chosen to provide

GAIN

=

RB

-

A

R

input

resistance

but

may

the classic differential connection for an operational amplifier

in

any

book

on

Operational Amplifiers3.

and

Applications"

by

Tobey.

Graeme

&

Huelsman.

McGraw-Hill

1971.

4-2

DAS-4

Fig

MANUAL

4.3

is a variation

on

the circuit of Fig

4.2

and adds

APPLICATIONS

two

voltage followers to this circuit to

provide a very high input impedance for sensitive signals.

if

Finally

you want

integrated circuit manufacturers as a single component.

to

buy a ready made differential amplifier, this

In

this

part

is available from

form

it

is called

an

instrumentation amplifier, some types include gain setting resistors and others require external resistors. Instrumentation amplifiers are usually optimized for operation at high gains with small

signals and usually have zero

Although more costly

than

simple operational amplifiers, operation under high gain conditions

drifts

of

less than a few millionths (microvolts) per degree

C..

usually demands the extra stability and common mode rejection that instrumentation amplifiers provide.

If

you are using the

+/-

12v & +5v power that can

STA-08

screw connector accessory, there

be

used to accommodate attenuators, filters or amplifiers.

is

a small bread board area with

HI

LO

@

LO@

HI@

+

-

'

-

I

-

I

FIG.

INPUT

1

,AN'(

ANALOG

INPUT

-L.L.

4.3

HIGH INPUT IMPEDANCE DIFFERENTIAL FIMPLIFIER

INSTRUIENTATION OUT

AMPLIFIER INPUT

SENSE

REFERENCE

GND.

I

A

TO GAS-4

J

TO

DAS-4

1

TYPICFIL INSTRUMENTATION AMPLIFIERS:-

LM363 Nf3TIONHL SEMICONDUCTOR AMP-01 PRECISION MONOLITHICS AD-524 fWFILOG

I

NA-102 BURR

FIG.

4.4

CORRECT CONSCTIONS

FOR

PIN INSTRUMENTATION WIPLIFIER

DEUICES

BROWN

+L.L.

GND.2

4-3

APPLICATIONS

DAM

MANUAL

For a ready made differential input with instrumentation amplifier, you

from

expansion multiplexer the DAS-4 and each EXP-16 provides 16 differential inputs and a common instrumentation amplifier connected one DAS-4 providing a total of 128 channels channels being individually gain selectable. The EXP-16 is powered by the computer and the sub-multiplex channel

The ISO-4 is a 4 channel isolation amplifier that is plug compatible with DAS-4. Up to

1S0-4'~

500

EXP- 16 and

These various methods provide a variety complexities. Almost certainly, one

4.3

Process control current loop transducers are easily interfaced to DAS-4 by adding a suitable

shunt resistor acToss the input. Since the maximum current will be 20mA and the maximum input range temperature coefficient metal temperature. Using this interface, the 4-2OmA working range of the current loop corresponds to

102 bits

can

be

volts and gains ranging from 1 to

ISO-4.

4-20mA

is

+5v, a

of

input,

to

connected to one DAS-4. Each channel provides analog input isolation of up to

CURRENT

250

ohm

a resolution of about 1%.

MetraByte.

one of DAS-4's input channels. Up to 8 EXP-16's can

is

selected by the

precision shunt resistor will be required. This should

film

This

is

designed to connect directly through flat cable

of

differential analog input, each group

of

DAS-4

1OOO.

of

these

digital outputs

See

our

catalog for detail specifications on the

different interfacing solutions of different costs and

will

be appropriate for your requirements.

(OP1-4).

LOOPS

or wire wound construction for stability with time and

can

add the EXP-16

be

connected to

be

to

of

16

32

.

of low

4.4

The 5v signals etc. but should not be heavily loaded. The maximum available output current is

4.5

DAS-4 provides digital inputs.

The digital outputs correspond the control register (see section 3.1.5). When you need The DAS4.BIN routine does this for temporary storage. If capability

reading the status register,

enabled.

Digital outputs can sink interface to

THE

A/D

voltage reference (Vref) is brought out for users.

USING

to

maintain the

in

your

CMOS, lKohm pull-up resistors connected to +5v should be attached to

REFERENCE

DIGITAL

4

'ITLDTL

state

of bits

you

are not using this routine, it may

own software. The multiplexer address bits

so

the only state that has

8mA

INPUT/OUTPUT

compatible digital outputs (OP1-4) and

to

bits 4

0

(5

-

7

of

the control register and are accessed by writing to

write

-

3

that control the multiplexer address and interrupt enable.

you

by holding an "image" of

to

be

standard

TTL

loads or 20 LSTTL loads).

It

may be used for offsetting

3

TTLDTL,

to the control register you will usually

the

control register

be

advisable to set

0

-

2

can always

stored is whether

or

up

be

determined by

not the interrupt is

Lf

you

5mA.

compatible

a similar

wish to

the

outputs.

in

4-4

DAS-4

MANUAL

APPLICATIONS

This will raise the logic high output level CMOS interface.

If EXP-16 or committed to providing.the sub-multiplex address.

Digital inputs data is easily obtained by masking out these bits using a logical AND operation. The inputs present a -0.4m.A loading corresponding

4.6

You

16

added to one DAS4 providing a total of 128 channels. The sub-multiplexer address is set digital outputs OP1-4

multiplexer address with Mode 9 and repeat the scan of Mode 2 on the next set of sub-multiplex

channels etc.

The ED-16 cards are designed

connect to DAS-4. One cable should

connections operated at a different

channel functions and

ADDING MORE ANALOG INPUTS

may add sub-multiplexers

channels per input and is

IS04

are

expansion interface(s) are

available through bits

to

any

directly

so

that a typical scan would

to

cascade with flat cable and connectors similar to that used to

made by screw connectors, and each EXP-16 (goup of 16 channels) can

gain.

In

this way a system can be confiewed with a variety of different

gains,

single ended and differential.

from

its minimum

used,

4

-

6 of the status register (see section 3.1.4). The

to

1

LSTL

or

all

of

the 8 analog inputs. MetraE3yte’s EXP-16 provides

plug compatible with DAS-4. Up to 8 EXP 16’s can

be

provided for each EXP-16.

be

load,

to

‘ITL

level

of

2.4~

to

+5v

suitable for

then the digital outputs are usually fully

digital

use

Mode 2 and then increment the

All

analog channel

be

by

sub-

be

4.7

THERMOCOUPLES

Low level transducers such as thermocouples and strain gage bridges (load cells, pressure

force transducers) require amplification before applying to the high level DAS4 inputs. The

EXP-

amplification and also includes

.thermocouples. EXP-16

and

of DAS-4 will not give very precise results when used

DAS-8 will give better performance. Most thermocouples about and since the resolution of the DAS-4 which for many purposes is a coarse resolution. This is why a 12 bit converter with 16 times better resolution can will give better results. However, for alarm or threshold sensing, the DAS-4 may be adequate when

For inexpensive temperature measurement

semiconductor temperature transducers are a good choice. The most popular types are the AD590 (Analog Devices) which behaves like a constant current source with at output devices can

INTERFACE

TO

TRANSDUCERS,

ETC.

16 expansion multiplexer kcorporates an instrumentation amplifier that can provide stable

also

includes spaces for

40

rnicrovolts/deg C.. Amplified by a gain of 1000, this corresponds to 40 millivolts/deg C.

0

deg.C. and a scaling

of

2.73 volts at 0 degC. and a temperature coefficient

be

powered from

circuitry

will

handle most interfacing requirements

filters,

used

with a thermocouple, or if the accuracy is not very demanding.

of

shunts and attenuators.

is

1uNdeg.C. and the LM335 (National Semiconductor) that

the

+12v available from the computer and interfaced to DAS-4

that allows cold junction compensation of

to

D.C. output transducers

In

general, the limited 8 bit resolution

with

thermocouples, MetraByte’s 12 bit

(J,K,T

39 millivolts/bit, each bit will correspond to 1 deg. C.

in

the

-50

to

+125

of

&

E

characteristics) produce

deg. C. temperature range,

an

output of 273uA

lOmV/deg.C.. Both

of

has

these

&

an

4-5

APPLICATIONS

DAS-4

MANUAL

either directly than a thermocouple for ambient temperature measurements, and

4.8

The +5v and +/-12v I.B.M. are provided as a convenience to users who wish to add external signal conditioning and logic circuits but they should connected to the internal circuitry of your operational amplifiers, comparators, indicators relays etc. and the +5v will power logic circuits,

TTL,

supplies

The available power

installed. Consult your users technical reference manual for details specification. Due to cabling and connector limitations, draw to less than milliamps). Most analog circuits will consume a few tens of milliamps which is negligible.

If power supplies

on

into consideration.

signal sources which could damage

provide an external (and more easily repaired) power supply

POWER OUTPUT FROM

CMOS

the power outputs are subjected

again

your

or

through a simple operational amplifier. These can give much better resolution

are

easier to interface.

THE

P.C.

bus supplies are available on the

be

used

with caution and an awareness that these same supplies are

PC.

The +/-12v can

etc.

Careful use of these supplies can often avoid the expense and bulk

to

power your signal sources and the nuisance of multiple power switches.

will

depend on the type of computer and what other peripheral cards

1

amp from any supply (the -12v supply

to

an

over current (overload) or over voltage condition, most

are

designed

to

restore operation after removing the fault. Although these protective devices

computer supply, do not depend on them, use your computer power with care and

If

there is any possibility

to

shut down

and

the computer will have to

of

frequent short circuits

your

whole computer, then it is strongly advisable

DAS-4 CONNECTOR

DAS-4

be

it

is recommended that you limit current

is

usually limited

or

for

your

rear connector. These

used

for analog circuits,

of

external

on

the

power supply

to

a

few 100

be

turned

shorts to high voltages and

user circuits.

off and

are

turned

are

built

to

4.9

PRECAUTIONS IN

USE

-

NOISE, GROUNDLOOPS

ANDOVERLOADS

Unavoidably, data acquisition systems give users access to inputs to the computer.

whatever else

an instant can cause extensive and costly damage to

MetraByte can accept no liability for this type of accident.

1.

2.

3.

There are

Digital common

current (power supply) currents. Low level ground

functions. It is only meant

vou

do. Pet these inDuts mixed

- Avoid

-

two

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

Use necessary.

ground connections

is

direct

isolation amplifiers and transformers where

the noisy or "dirty" ground that is meant to carry

UD

with

connections to the

on

the rear connector called DIG.

to

carry signal currents (less

A.C.

the

A.C.

DAM

As

line.

is

the signal

than

line.

an aid

a few

An

inadvertent short

as

well

as

your computer.

to

avoiding this problem:-

so

that

to

high

COM.

all

digital signal and heavy

ground

mA)

and

for

all

analog input

and is the ground

Do

L.L.

NOT,

can

in

GND.

4-

6

DAS-4

MANUAL

APPLICATIONS

reference for the

be

may

other

many millivolts difference between

and

the computer

A/D

channels. Due to connector contact resistance

the

two

grounds although they are connected to each

and

power line

grounds

on

the DAS-4

board.

and

cable resistance there

4-7

--

DAS-4

5.1

The 8 bit resolution and 39 millivolt bit size

units will most likely never require further calibration.

CAL.EXE from DOS, or

multimeter with a variable

pr0,ga.m

inputs can also be checked from the calibration program. The

locations are

MANUAL

Section

CALIBRATION AND

CAL-BAS

D.C. source attached connected to one or more of

will

guide you through the necessary adjustments. Operation

shown

in Fig,

5.1.

from

TEST

of

the DAS-4 is

BASIC(A).

5

TEST

If

you wish to check the calibration,

You

should connect a voltage calibrator or

CALIBRATION

so

coarse that once correctly set,

the

of

the

digital

DAS4

calibration potentiometer

AND

inputs, the CAL

outputs and

TEST

run

5.2

MemByte products

data acquisition products

connecting

sort

The integrated circuits that provide the

installed in sockets.

inp~ or output, you can replace these inexpensive parts yourself

Alternatively, MetraByte can service your

customer service. We will issue you with a Return Material Authorization (R.M.A.) number

which should

without an

If

the problem and under what conditions

5.3

MetraByte has a staff of technical assistance engineers. Should you have a problem or require help or advice on using any MetraByte product, call (617)-880-3000. Technical assistance is free

of

SERVICE

inputs

of calamity but

be

attached to any packages returned

R.M.A.

the fault is not obvious,

AND REPAIR

are

warranted for 1 year against defects

are

susceptible to damage

or

grounds

if

you do, there are a couple of remedies.

In

the event that you apply

number

to line voltages. We hope you will take precautions to avoid this

digital

as

it

greatly complicates

it

will help our repair technicians if you include a brief note describing

it

occurs.

TECHNICAL ASSISTANCE

charge and

is

available on Mondays thru Fridays from

in

workmanship and material. Most

from

input and output and the analog multiplexer are

an

over voltage and succeed in "zapping" an

DAS-4,

simply call (617)-880-3000 and ask for

to

MetraByte. Please do not return material

the

handling

9:OO

external over voltages such

if

you

wish.

of

the material and paperwork.

a.m. to

5.00

p.m.

E.S.T.

as

CALIBRATION

AND

TEST

A/D

Full

Scale

DAS-4

MANUAL

f

A'D

r

*

I

Base

switch

Address

Fig.

5.1

Interrupt

(X

DAS-4 ADJUS'MENTS,

Level

=

inactive)

Select

JUMPERS

AND SWITCH LOCATIONS

7

DAS-4

MANUAL

Appendix

APPENDIX

A

A:

CONNECTIONS

A.l

The main analog and digital

computer case at the rear of the board. The pin functions are as follows (see Fig A.l for

locations):-

MAIN

-

I/O

CONNECTOR

I/O

is

NAME

via a 37

pin D type connector that projects

FUNCTION

through

the

1

2 3 4

5

6

7

8

9

10

11 DIG.COM. Digital Common. Return

+12v

-

OP1.

OP2 OP3 OP4 Digital output

+12v power supply from bus (observe loading limits)

No

connection

No

connection

No

connection

No

connection

No

connection

Digital output Digital output Digital output

for all logic signals

power supply currents.

Connected

to

#1

#2

#3

#4

and

computer frame.

P.C.

12

13

14 15

16

17

18

L.L.GND. L.L.GND. L.L.GND. L.L.GND. L.L.GND. L.L.GND. L.L.GND.

Low

level grounds.

are

These

and shields for the analog input channels.

common returns

A-

1

APPENDIX

A:

CONNECTIONS

DAS-4

MANUAL

19

20

21

22 23 24

25 26

27

28

29

VREF

-

12v

-

INT.

IN.

IP1

IP2

IP3

DIG.

COM.

t5v

+5.0Ov(+/-O.2~)

reference voltage

-

12v

power

(observe loading limits).

No

connection

No

connection

No

connection

Interrupt input. Positive edge triggered input.

Digital input Digital Digital Digital common. (same as

pin +5v power

(observe loading limits).

input

11).

from

#1

#2

#3

from

precision

from

A/D.

P.C.

bus.

P.C.

bus

30

31

32

33

34

35

36

37

The mating connector

#DC-37S

available e.g. Amp

for soldered connections. Insulation displacement (flat cable) types are readi!y

#745242-

IN

7

IN6

LN5

IN4 IN3

IN

2

IN1

IN

0

for

DAS-4

1.

is a standard

#7

Channel Channel Channel

Channel Channel #3 analog input Channel Channel Channel

37

pin D type female such as IlT/Cannon

analog input

#6

analog input

#5

analog input

#4

analog input

#2

analog input

#1

analog input

#O

analog input

A-2

1

DAS-4

A.2

Digital

outputs

MANUAL

REARVIE\

Vref L.L. GND. L.L. GND. L.L. GND. L.L. GND. L.L. GND.

GND.

L.L. L.L. GND. DIG.

COM.

OP4

N.C. N.C.

N.C. N.C. N.C.

+

12v(

’)

OF

Rear

b

18 17

16

15

14

13

12

11

LO

9

8

7

6

5

4

3

2

DAS-4

view

37 36 35 34 33 32

31

30 29

28 27

26 25 24

23 22 21

20

ANALOG ANALOGIN1 ANALOGIN2

ANALOG

ANALOGIN4 ANALOGINS ANALOGIN6 ANALOG IN 7

+5v

DIG.

IP3J

IP1

”’:

INTERRUPT

N.C.

N.

C.

N.C.

-

12v(

CO

(*)

COM.

*)

APPENDIX

ECTOR

IN

0

?

j

1

I

IN

3

f

1

)

Digital

INPUT

Analog

inputs

forreturn)

inputs

signal

(use

A:

CONNECTIONS

L.L.

GND’S.

*

-

These

are

power

outputs

from the

computer.

A-3

~

-

DAS-4 MANUAL

B.l

B.2

POWER CONSUMPTION

+5v

supply

+12v supply

-12v supply

ANALOG

APPENDIX

Appendix

B

SPECIFICATIONS

-

170mA

typ.

/

240mA

7mAtyp./llmArnax.

7mA

typ. / 11mA

ma.

max.

INPUT SPECIFICATIONS

B:

SPECIFICATIONS

8

B.3

analog input channels each with the following specification:-

Resolution Accuracy Full scale

coding Over voltage

Configuration Input current

Temperature Coefficient Zero, +/-lo microvolt/deg.C. max.

A/D

SPECIFICATION

me

-

8

bits. (39mV/bit)

0.2%

of

reading

+/-5

volts Offset binary Continuous single channel to +/-35v

Single ended.

lOOnA max at 25 deg.C.

Gain or

Successive approximation.

F.S.,

+/-

1

bit.

+/-5Oppddeg.C. max.

Resolution Conversion

time.

-

8

bits

20

microseconds typ.

30

microseconds

ma.

B-

1

APPENDIX

B:

SPECIFICATIONS

DAS-4

MANUAL

B.4

B.5

Monotonicity Linearity

Zero

drift

Gain drift

-

Guaranteed over operating temperature range. +/-1

bit.

10ppddeg.

50

ppddeg. C max.

C.

SAMPLE HOLD AMPLIFIER

Acquisition time

Dynamic

sampling error

REFERENCE

Reference voltage

-

10 microseconds

for

full

scale step input

2mV @ 2000v/sec.

VOLTAGE OUTPUT

-

+~.OV

+/-

0.2~

max.

to

0.1%

typ.

B.6

Temperature coefficient

Load current

DIGITAL

OP1-4 low voltage

OP 1-4 high voltage

IP1-3 low voltage

IP1-3 low current

IP1-3 high voltage

output

input

I/O

-

50

ppddeg.C max.

+/-5mA

0.5

2.7~

0.8~ max

-0.4mA

2.0~

max.

max

at Isink

min

at Isource = -0.4mA

max

min

=

8.0mA

B-2

IP1-3

current

input

-

20uA max. @ 2.7~

-

DAS-4 MANUAL

B.7

B.8

INTERRUPT

Type

Level Enable

Interrupts are latched in this flip-flop corresponds to the

flip-flop is cleared

acknowledge and re-enable the interrupt flop.

POWER OUTPUTS

IBM

P.C.

supplies

APPENDIX

B:

SPECIFICATIONS

INPUT

-

an

by a write to the CONTROL register. Service routines should

bus

-

Positive edge triggered 2

-

7

jumper selectable

Via INTE

internal flip-flop on the

INT

+5v

&

bit

+I-

of

CONTROL register

in

the

STATUS

12v

DAS-4

board. The state

register. The intempt

of

Tolerance

Loading

-

+5v

+/-5%

+12~

+/-5%

-12v +/-lo% Dependent

(see Section

on

other peripherals

4.8)

B.9 GENERAL ENVIRONMENTAL

Operating temperature

range.

Storage temperature

range

Humidity Weight

-

0

to

50

-20 to

0

to

90%

4

oz.

deg.

C.

+70

deg.C.

non-condensing.

(120

gm.)

--

DAS-16G

Data is stored

16

bits but the range becomes

+32,767

MANUAL

or

2

bytes

2’s

complement convention interprets the most significant bit as a sign bit

D7

0

STORAGE

in

integer variables

of

memory.

-32,768

.

1

to

1

16

+32,767

1

APPENDIX

Appendix

OF

(5%

bits

(a

1

INTEGER

type) in

of

data is equivalent

span

of

65,535).

.

1

1 1

C:

INTEGER

VAR.IABLE

STORAGE

C

VARIABLES

2’s

complement form. Each integer variable uses

to

values

Numbers are represented as follows:-

DO D7

11111111

.

from 0 to

Low

bvte High byte

65,535

so

the-actual

decimal,

.

DO

+lO,OOO

+l

0

-1 11111111 11111111

-

10,000

-32,768 10000000 00000000

Integer variables

16

and optimize execution speed, all data exchange via the

poses a programming problem when handling unsigned numbers

If you wish to input work out what

16

bit counter with execute most significant bit is variable value would between integer and real variables is therefore:-

0

1 0

00000000 00000001

00000000

11011000

A

Sign bit

bit

data of the

its

(1

if negative,

are

the most compact

8254

or

output

2’s

compliment signed equivalent is. As

50,000

PRINT

HEX$(50000).

1

this would

be

50,000 - 65,536 = -15,536.

0

1 1 1

oooioooo

00000000

iiiioooo

0

if

positive)

form

of

storage for the

interval her and

an

unsigned integer greater than

decimal. An easy way of turning this to binary is

This

returns

be

stored as a negative integer and in fact

for

representation of unsigned numbers between 0 and

C350

so

to conserve memory and disk space and

CALL

or binary

12

bit data from the

is

through integer type variables. This

in

the range

32,767

an

example, assume we want to load a

1100 0011 0101

The programming steps

then

A/D

converter

32,768

to

the

to

65,535.

it

is necessary to

enter BASIC and

0000.

Since the

correct integer

for

switching

65,535

From real variable

From integer variable

N

XXXlO

xxx20

(0

<= N <=

IF

N%

to

IF

65,535)

N<=32767

real variable

N%

>=

0

THEN

to

integer variable

THEN

N%

N:-

N=N%

=

N

ELSE

N

N%:-

N%

=

N%

N

-

+

65536

c-

1

Index

A

A/D

-

channel inputs 4-1

A/D

-

conversion by software command 3- 17

A/D

-

conversions

A/D

-

conversions transfer

-

AD

A/D A/D A/D A/D A/D

Accessories 1-2

Adding analog inputs 4-5 Address map 3-2 Amplifiers Analog input channels 4Analog inputs B-1 Analog trigger 3-23 Applications 1-2,4-1 Assembly language programming 3-32 Assistance

data format 3-3

-

reading data 3-3

-

sample rate 3-32

-

specification

-

starting conversion 3-2

-

stams

of

&

-

direct

1-1,

operation 3-27

attenuators

technical

5-1

to array 3-19

by

interrupt 3-21

B-1

4-2

1

B

Base address 2-2

Base address switch Base

I/O

address 2-1 BASIC BASIC Compiler 3-32

-

some useful commands 3-5

2-2

C

Calibration CALL routine: Format 3-8,3-9 CALL routine: Initialization 3-13 CALL routine: Loading 3-6 CALL routine: Modes 3-12 Channel inputs Connecting analog inputs 4-1 Connector assignments Control register 3-4

Current

5-

loops

1

4-

1

A-1

4-2OmA 4-4

D

DAS4.ASM driver source listing 3-1,3-32 DAS4.BI.N 1-1, 3-1,3-6

Index-

1

INDEX

DAS-4 MANUAL

DAS4.0BJ Differential inputs 4-2 Digital Common 4-6 Digital Digital Digital Disk back up

3-33

VO

1-1,4-4, B-2

VO

-

Output to OP1-4 3-29

VO

-

Reading IP1-3 3-28

2-1

E

Environmental specification Error codes EX0 & EXOO.BAS 3-8 Examples of programming Execution time 3-32 Expansion multiplexer 1-2,4-4,4-5

3-30

B-3

3-31

G

Ground loops Grounds 4-6

1NSTALL.EXE 2-2 Installation Instrumentation amplifier 4-3 Integer variables -2’s complement storage Interrupt - data transfer after operation 3-25 Interrupt Intempt input 1-1, B-3 Isolated analog inputs

4-6

2-

1

-

determining status of transfer 3-27

1-2

C-

1

L

L.L. Ground 4-6 Loading Low-level signals

Measuring voltage 4-2

Memory Memory size Mode Mode Mode 2 Mode Mode 4 Mode Mode

Mode 7 Mode Mode 9 Mode error codes 3-30 Multiple Multiplexer: Setting scan limits Multiplexer control 3-5

DAS4.BIN

-

data transfer after interrupt 3-25

3-7

0

-

Initialize

1

-

Set scan limits 3-15

-

Single

3

-

A/D

-

A/D convert on interrupt 3-21

5

-

Analog trigger 3-23

6

-

Transfer data after interrupt 3-25

-

Read status 3-27

8

-

Digital input 3-28

-

Digital output 3-29

DAS-4

3-6

4-3

3-13

A/D

conversion 3-17

convert to array 3-19

boards

3-33

3-15

Index-2

DAS-4

MANUAL

0

ON

TlMER command

P

Power consumption

Power outputs

Precautions Process control current loops Programming

Programming - example sequences

1-1,4-6, B-3

in

use

3-1

R

Reference Voltage Repair

5-

1

S

Sample-hold

Sampling rate

Screw terminal board

Semiconductor temperature sensors

Setup

Single ended inputs

software

2-1

Software

Source

Specifications

Speed

Status register

STRIP.EXE

3-32

B-2

3-32

1-1

supplied

listing

1-2

B-

3-3

strip chart program

B-

4-6

1-1, B-2

1-2

4-2

on

disk

1

3-5

1

3-31

INDEX

4-4

3-31

4-5

3-33

T

Technical assistance

Temperature measurement

Temperature sensors - solid state

Thermocouple measurement

5-1

4-5

1-2

V

Voltage reference

4-4

W

WAITc01n~11and3-5

4-5

Index-3

Tektronix DAS-4 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual