Brainboxes AD-593, AD-604, AD-923, PC AD1200 User Manual

2.1 EDITION Feb 1995

da

1200Series

PC AD1200 Reference

Thank You For Buying

PC AD1200

Interface!

We proudly present the PC AD1200 Interface Board.

The PC AD1200 Interface allows the PC user to measure
and control ’Real World’ analogue signals. AD1200 is 100%
compatible with the widely available DT2811 card and yet has
features that surpass and out perform that product. Blending the
discrete digital domain of computers with the infinitely variable
Analogue realm brings great power to the user, allowing control
and monitoring of almost any process. AD1200’s mix of high
performance Analogue to Digital input, Digital to Analogue
output, Digital input and Digital output hardware with a fully
functioned software package provides a straight forward route to
excellence in signal acquisition. Extend your grasp with AD1200.

Your board is designed and manufactured in England, and
our policy is one of complete support to our dealers and direct
to our users. Please note, PC AD1200 is designed ’in house’ and
is completely understood by our staff. Its great strength is the
software support we give it. Our intention is to supply the
software and any technical information you may need to allow
you to exercise complete control over the AD1200 board and
software. After searching the manuals, do not hesitate to contact
us on our HOTLINE numbers given on Intro Page-2, if you
need help.

We are particularly keen to provide new operating system
or language drivers to expand the range of applications using our
PC AD1200 board.

We trust that if you adhere to the following procedures you
will enjoy many years of useful service from your AD1200 card.

Intro-3

PC AD1200 Reference

PC AD1200 MANUAL____________________

The Layout Of This Manual._________________________

This manual is a complete description of how to install,

configure and use the PC AD1200 interface board.

The PC AD1200 card, like our other PC add on boards, is
an extremely easy to use and understand implementation of
Analogue interfacing for IBM PC and compatible computers. We
have truly tamed the Analogue world and the PC BUS allowing
you to get the most out of your data acquisition system!

Chapter 1, Introduction To The Analogue
World

, describes the features of the range of AD1200 cards,
discusses the fundamentals of Analogue to Digital conversion,
Digital to Analogue conversion and explains exactly how the
AD1200 range implements these. Downwards compatibility with
the DT2811 is discussed as well as the extra high performance
features that distinguish the AD1200 range, this improved design
whilst retaining exact compatibility with other manufacturers
products gives AD1200 extreme flexibility in its application and
use. Converter throughput, interrupt and DMA driven i/o are
explained together with a complete description of the AD1200’s
timing and control modes.

Chapter 2, Installation Guide, shows you how to

configure and install the PC AD1200 board in one of the
expansion slots of your computer and gives the default setting of
all configurable options. All settings for I/O base address, IRQ
and DMA channels, ADC and DAC voltage ranges are shown.
Details of how to connect up the AD1200 to the users system
are given.

Intro-4

PC AD1200 Reference

Chapter 3, The AD1200 Register Map, details the

programmable status and control registers on the card. Whilst
most users will use the bundled driver software and so find this
information be be unnecessary it is included to make this manual
as complete as possible, to allow you to cover every eventuality.

Chapter 4, Calibration, shows how to perform a

calibration of the AD1200 analogue circuitry. The use of the
calibration software, the position and function of the onboard
trimmer pots and use of ancillary equipment are all described.
Calibration should be performed at regular intervals to ensure
that the AD1200 remains in specification, and that your analogue
measurements are traceable back to nationally and internationally
recognised standards.

Chapter 5, Technical Specification, gives the

complete technical specification on the AD1200 series of cards.

The Cumulative Index covers the complete contents of

the manual.

Intro-5

PC AD1200 Reference

Outline Contents.________________

Chapter 1. Introduction To The Analogue World.
Chapter 2. Installation Guide.
Chapter 3. The AD1200 Register Map.
Chapter 4. Calibration.
Chapter 5. Technical Specification.
Cumulative Index.

Chapter 1 Introduction To The Analogue World.___________________________________________

Introduction. 1
The PC AD1200 Range Of Cards. 2
From AD1221 Up To AD1200. 3
DT2811 Superset. 4
Introduction To Analogue. 5
Unipolar Vs Bipolar Voltage Ranges. 8
Differential Vs Single Ended Signals. 8

The Analogue To Digital Converter. 9

Input Channel Selection. 10
Programmable Gain. 11
Analogue Input Ranges. 11
Programmed I/O, Interrupts and DMA. 12
Programmed I/O. 12
Interrupt Driven I/O. 12
DMA, Direct Memory Access. 13
The Pacer Clock. 13
A/D Throughput and Pipelining. 14

A/D Operating Modes. 16

A/D Modes 0, 1, 2 & 3. 17
Mode 0, Single Conversions. 17
Mode 1, Continuous Conversions, Int Trig & Clock. 18
Mode 2, Continuous Conversions, Ext Trig Int Clk. 18
Mode 3, Continuous Conversions, Ext Trig & Clock. 19

The Analogue To Digital Converter. 20

D/A Programmed I/O. 20

Intro-6

PC AD1200 Reference

D/A Interrupts and DMA. AD1200 Card Only. 20

Digital I/O Ports. 21

Digital Port Programmed I/O. 21
Digital Port Interrupts and DMA. AD1200 Only. 21

Screw Terminal Board. 22
4-20mA Current Conversion Options. 23

Chapter 1 List Of Figures._______________________

Figure 1-1. AD1200 Series Common Properties. 2
Figure 1-2. AD1200 Series Options. 3
Figure 1-3. AD1200 card Vs DT2811. 5
Figure 1-4. One Bit A/D Conversion. 6
Figure 1-5. Two Bit A/D Conversion. 6
Figure 1-6. Three Bit A/D Conversion. 7
Figure 1-7. Bit Weights And Resolution. 8
Figure 1-8. Mode 0 & 1 Bits. 16
Figure 1-9. Extended Mode Bits. 17

Chapter 2 Installation Guide.__________________________

Introduction. 24
Configuring The PC AD1200 Board. 24
Setting The PC AD1200 I/O Address. 26
Using More Than One PC AD1200 Board. 33
Interrupt Selection. 33
Setting The Interrupt Jumper Block. 34
DMA Selection. AD1200 Only. 35
Setting The DMA Channel Jumper Block. 36
D/A Output Range Selection. 37
A/D Configuration. 38
8254 Counter Timer Pinouts. 43
Installing The PC AD1200 Board In The Computer. 44
AD1200 Backplane Signals. 46
Signal Types. 47
Wiring Guidelines. 49
Twisted Pair Cables. 49

Intro-7

PC AD1200 Reference

Shielded Cables. 49
Input Voltage. Overvoltage Warning! 50
Problems! 50

Chapter 2 List Of Figures._______________________

Figure 2-1. AD1200 Card Layout. 25
Figure 2-2. AD1210 AD1211 Card Layout. 26
Figure 2-3. AD1220 AD1221 Card Layout. 26
Figure 2-4a. AD1200 Factory Set DIP Switches. 27
Figure 2-4b. AD1210-21 Factory Set DIP Switches. 28
Figure 2-5. I/O Addresses To Avoid. 28
Figure 2-6. Likely I/O Address. 29
Figure 2-7a. AD1200 Base Addresses. 29
Figure 2-7b. AD1210-21 Base Addresses. 31
Figure 2-8. The IRQ Jumper Block. 35
Figure 2-9. The DMA Jumper Block. 37
Figure 2-11. A/D Channel Input Select. 39
Figure 2-12. AD1200 A/D Input Range Selection. 40
Figure 2-13. AD1210 A/D Input Range Selection. 41
Figure 2-14. AD1220 A/D Input Range Selection. 42
Figure 2-15. OUT0 Via Digital Input Bit 7, Pin36. 43
Figure 2-16. Remove Cover Mounting Screws. 44
Figure 2-17. Removing The PC Cover. 44
Figure 2-18. Removing Blanking Cover. 45
Figure 2-19. Inserting The PC AD1200 Card. 45
Figure 2-20. AD1200 J2 Pin Outs. 46

Chapter 3 AD1200 Register Map._____________________________

Introduction. 51
I/O Address Map. 51
Register Types. 52
Read Write Assignments. 52
Power Up Conditions. 53

The A/D Control Status Register. 53

Bit 7 A/D Done, Read Only. 53
Bit 6 A/D Error, Read Only. 54

Intro-8

PC AD1200 Reference

Bit 5 A/D Busy, Read Only. 54
Bit 4 Clear A/D Error, Write Only. 54
Bit 3 DMA Enable, Read / Write. AD1200 Only 54
Bit 2 Interrupt Enable, Read / Write. 55
Bits 0 & 1. Mode Bit 0 & 1. Read / Write. 56
Initialising The A/D Converter. 57

The A/D Gain Channel Register. 58

Bits 6 & 7. Gain select. Read / Write. 58
Bits 4 & 5. Reserved For Future Expansion. R/W. 59
Bits 0, 1, 2 & 3. Channel Select. Read / Write. 59

The A/D Converter Input Registers. Read Only 60
The DAC0 D/A Converter Output Registers. 62
The DAC1 D/A Converter Output Registers. 63
The Digital Output Port Register. Write Only 65
The Digital Input Port Register. Read Only 66

The Timer & Extended Mode Register. Read/ Write 66

Bits 0-5, TIMER Pacer Clock Divisor Bits. R/W. 67
Bits 6 & 7 XMODE, Extended Mode Read/Write. 69

The 8254 Counter Timer Registers. Read/ Write 70

Chapter 3 List Of Figures._______________________

Figure 3-1. AD1200 Register Map. 51
Figure 3-2. A/D Control Status Register. 53
Figure 3-3. Mode 0 & 1 Bits. 56
Figure 3-4. AD1200 Extended Mode Bits. 57
Figure 3-5. AD1210-21 Extended Mode Bit. 57
Figure 3-6. A/D Gain Channel Register. 58
Figure 3-7. Gain Selection. 59
Figure 3-8. Channel Selection. 60
Figure 3-9. ADC Low Byte Input Register. 61
Figure 3-10. ADC High Byte Input Register. 62
Figure 3-11. DAC0 Low Byte Output Register. 63
Figure 3-12. DAC0 High Byte Output Register. 63
Figure 3-13. DAC1 Low Byte Output Register. 65

Intro-9

PC AD1200 Reference

Figure 3-14. DAC1 High Byte Output Register. 65
Figure 3-15. DIGOUT Output Register. 65
Figure 3-16. DIGIN Output Register. 66
Figure 3-17. TIMEREX Register. 67
Figure 3-18. Pacer Clock Divisor 68
Figure 3-19. AD1200 Extended Mode Bits. 70
Figure 3-20. AD1210-21 Extended Mode Bit. 70
Figure 3-21. 8254 Counter Timer Register Map. 71

Chapter 4 Calibration.____________________

Introduction. 72
Calibrating The Digital To Analogue Output. 72

Outline. 73
Equipment Required. 73
DAC0 Calibration Procedure. 74
DAC1 Calibration Procedure. 75

Calibrating The Analogue To Digital Input. 77

Outline. 77
Equipment Required. 78
ADC Calibration Procedure. 78

Chapter 4 List Of Figures._______________________

Figure 4-1. DAC Trimmer Pot Layout. 73
Figure 4-2. DAC0 Calibration Wiring Diagram. 75
Figure 4-3. DAC Calibration Values. 75
Figure 4-4. DAC1 Calibration Wiring Diagram. 76
Figure 4-5. ADC Trimmer Pot Layout. 77
Figure 4-6. ADC Calibration Wiring Diagram. 78
Figure 4-7. Unipolar ADC Calibration Values. 79
Figure 4-8. Bipolar ADC Calibration Values. 80

Chapter 5 Technical Specification.______________________________

Introduction. 81
Analogue Inputs. 81
Analog Outputs 82
Digital I/O 82
Pacer Clock. 83
Power Consumption. 83

Intro-10

Introduction AD1200 Reference

CHAPTER 1

INTRODUCTION TO

THE ANALOGUE

WORLD.

Introduction.____________

This chapter describes the features of the range of AD1200
cards highlighting the differences between them, discusses the
fundamentals of Analogue to Digital conversion, Digital to
Analogue conversion and explains exactly how the AD1200
range implements these.

Downwards compatibility with the DT2811 is discussed as
well as the extra high performance features that distinguish the
AD1200 range, this improved design whilst retaining exact
compatibility with other manufacturers products gives AD1200
extreme flexibility in its application and use.

Converter throughput, Programmable Gain input, interrupt
and DMA driven i/o are explained together with a complete
description of the AD1200’s timing and control modes.

Note that throughout this manual reference is made to the
AD1200 series as either AD1200 series or as AD12XX card,
meaning that this information is common to all cards in the
AD1200 family.

When AD1210, AD1211, AD1220, AD1221 or the term
’AD1200 card’ the information is specific to those particular
cards mentioned.

Chapter 1 Page 1

AD1200 Reference Introduction

The PC AD1200 Range Of Cards._____________________________

The AD1200 series is a family of 12 bit analogue interface
cards. Currently 6 different cards are available. Each card has all
the base features of the range, the distinguishing features of each
card being variations in A/D throughput, Programmable Gain
ranges and DMA capabilities.

Figure 1-1. AD1200 Series Common Properties._________________________________________

Analog Input: 12 bit

Channels Type: 16 Single Ended
(jumper OR 8 Differential

selectable) OR 16 Pseudo Diff

Channel Select Programmable
Bipolar Input: ±10Volt, ±5Volt, ±2.5Volt
Unipolar Input: 0~10Volt, 0~5Volt

Interrupts

A/D Done IRQs: Yes
Analog Output: Two 12 bit DACs
Bipolar Output: ±10V, ±5V, ±2.5V
Unipolar Output: 0~10Volt, 0~5Volt
Throughput: 100kHz per DAC

Digital I/O

TTL output: 8 bit
TTL input: 8 bit
Throughput: 1MHz
Pacer Clock 0.005Hz-600kHz
External Clock: Yes (to 1Mhz)
External Trigger: Yes (-ve edge).

The common features of the AD1200 range are comprehensive
and sophisticated enough to make even the AD1221 a complete
data acquisition system on a single plug in board.

Page 2 Chapter 1

Introduction AD1200 Reference

Figure 1-2. AD1200 Series Options._______________________________

ЪДДДДДДДДДДДДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДД¿
³

Card

³

AD1221³ AD1220³ AD1211³ AD1210³ AD1200

³
ГДДДДДДДДДДДДДДДДДДЕДДДДДДДЕДДДДДДДЕДДДДДДДЕДДДДДДДЕДДДДДДД´
³

A/D Throughput.

³

³ ³ ³ ³

³
³

30kHz:

³

AD1221³ ³ AD1211³ ³

³
³

100kHz:

³

³ AD1220³ ³ AD1210³ AD120

³
ГДДДДДДДДДДДДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДД´
³

Programmable Gain Input.

³
ГДДДДДДДДДДДДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДД´
³

None:

³

AD1221³ AD1220³ ³ ³

³
³

1-2-4-8:

³

³ ³AD1211H³AD1210H³AD1200H

³
³

1-10-100-1000:

³

³ ³AD1211L³AD1210L³AD1200L

³
ГДДДДДДДДДДДДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДД´
³

DMA Capabilities.

³
ГДДДДДДДДДДДДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДД´
³

None:

³

AD1221³ AD1220³ AD1211³ AD1210³

³
³

A/D Done:

³

³ ³ ³ ³ AD1200

³
ГДДДДДДДДДДДДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДД´
³

Pacer Clocked DMA.

³
ГДДДДДДДДДДДДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДД´
³

DAC0 Output:

³

³ ³ ³ ³ AD1200

³
³

DAC1 Output:

³

³ ³ ³ ³ AD1200

³
³

DIG Output:

³

³ ³ ³ ³ AD1200

³
³

DIG Input:

³

³ ³ ³ ³ AD1200

³
АДДДДДДДДДДДДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДЩ

From AD1221 Up To AD1200.__________________________

So progressing from the entry level AD1221 to the fully

featured AD1200 card we have the following.
AD1221 30kHz A/D throughput.

Improved DT2811 but without programmable gain.

AD1220 100kHz A/D through put.

Faster DT2811 without programmable gain.

AD1211

AD1211H 30kHz A/D throughput.

Programmable Gain of 1-2-4-8 for High level input
signals. DT2811 improved equivalent.

AD1211L 30kHz A/D throughput.

Programmable Gain of 1-10-100-1000 for Low level
input signals. DT2811 improved equivalent

Chapter 1 Page 3

AD1200 Reference Introduction
AD1210

AD1210H 100kHz A/D throughput.

Programmable Gain of 1-2-4-8 for High level input
signals. Faster DT2811 improved equivalent.

AD1210L 100kHz A/D throughput.

Programmable Gain of 1-10-100-1000 for Low level
input signals. Faster DT2811 improved equivalent.

AD1200

AD1200H DMA input from A/D converter or Digital Input port.

DMA output to D/A converter or Digital Output port.
100kHz A/D through put.
Programmable Gain of 1-2-4-8 for High level input
signals. The ultimate 12 bit data acquisition system.

AD1200L DMA input from A/D converter or Digital Input port.

DMA output to D/A converter or Digital Output port.
100kHz A/D through put.
Programmable Gain of 1-10-100-1000 for Low level
input signals. The ultimate 12 bit data acquisition
system.

DT2811 Superset.________________

The Ad1200 series of cards are a great improvement on
the DT2811 specification, they have wider input and output
ranges, faster settling and acquistion times, greater throughput
and DMA capabilities.

Page 4 Chapter 1

Introduction AD1200 Reference

Figure 1-3. AD1200 card Vs DT2811.________________________________

Feature AD1200 DT2811

Analog Input:

Bipolar Input: ±10V, ±5V, ±2.5V ±5Volt, ±2.5Volt
Unipolar Input: 0~10Volt, 0~5Volt 0~5Volt
Throughput:
Gains 1 - 10 100kHz 20kHz
Gain 100 100kHz 2.5kHz
Gain 1000 80kHz 2.5kHz

Analog Output:

Bipolar Output: ±10V, ±5V, ±2.5V ±5V, ±2.5V
Unipolar Output: 0~10Volt, 0~5Volt 0~5Volt
Throughput: 100kHz per DAC 50kHz per DAC

Programmable Gain

Maximum Gain: 1000 500

Interrupts

A/D Done Interrupt Yes Yes
DAC0 Interrupt Yes No
DAC1 Interrupt Yes No
Digital In Interrupt Yes No
Digital Out Interrupt Yes No

DMA

A/D Done DMA: Yes No
DAC0 DMA Yes No
DAC1 DMA Yes No
Digital In DMA Yes No
Digital Out DMA Yes No

Introduction To Analogue._______________________

Analogue signals are things with which we are all familiar.
The intensity of the light reaching our eyes, the volume of the
sound in our ears, the temperature of the air in the room around
us are all analogue values. That is the light intensity may vary
continuously and smoothly from utter darkness to broad daylight.
Our senses are able to easily discriminate between many subtle

Chapter 1 Page 5

AD1200 Reference Introduction

levels of illumination. This is not so with computers.

A computer uses numbers to represent physical quantities,
storing the values using bit patterns. Each bit in a computer’s
memory is either off or on, it cannot be half way on or nearly
on. If we are to store the value of light intensity on a computer
there must be some method of turning the smoothly varying real
signal value into a bit pattern in the computers memory. This
process is called analogue to digital conversion.

If only one bit is to be used to represent the light intensity
then the illumination would be divided into either on or off.
From total darkness to half light would be off, half light to full
illumination would be on. One bit gives two illumination states.
In general terms, resolution means separation into components.
The resolution of a converter is the smallest interval measurable
by the converter and this one bit converter’s resolution is 50%
of the signal.

Figure 1-4. One Bit A/D Conversion.________________________________

ЪДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДД¿
³

BIT PATTERN

³

ILLUMINATION LEVEL

³
ГДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДД´
³

1

³

ON

³
³

0

³

OFF

³
АДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДЩ

If two bits of computer memory are used to represent the
light intensity then the illumination would be divided into off,
dark grey, light grey and full illumination. Two bits gives four
illumination states.

Figure 1-5. Two Bit A/D Conversion.________________________________

ЪДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДД¿
³

BIT PATTERN

³

ILLUMINATION LEVEL

³
ГДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДД´
³

11

³

ON

³
³

10

³

LIGHT GREY

³
³

01

³

DARK GREY

³
³

00

³

OFF

³
АДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДЩ

With each increase in the number of bits used to represent

Page 6 Chapter 1

Introduction AD1200 Reference

the light intensity level there is a doubling in the number of
different states of illumination. We are able to resolve the light
intensity to smaller intervals to provide greater detail or
information about the light intensity.

Figure 1-6. Three Bit A/D Conversion._________________________________

ЪДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДД¿
³

BIT PATTERN

³

ILLUMINATION LEVEL

³
ГДДДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДД´
³

111

³

ON

³
³

110

³

LIGHTEST GREY

³
³

101

³

LIGHT GREY

³
³

100

³

MEDIUM LIGHT GREY

³
³

011

³

MEDIUM DARK GREY

³
³

010

³

DARK GREY

³
³

001

³

DARKEST GREY

³
³

000

³

OFF

³
АДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДЩ

As the number of bits used increases the number of states
doubles, the resolution of the converter increases, the smallest
resolvable interval decreases in size and the digital representation
of the light intensity begins to approach the smooth continuously
variable real world situation. 8 bit A/D converters use 256 states
to represent analogue values. 12 bit A/D converters use 4096
states to represent analogue values. 16 bit A/D converters use
65536 states to represent analogue values. This is summarised in
Figure 1-7.

The AD1200 series of cards use 12 bit A/D and D/A
converters, that is an analogue input is differentiated into 1 of
4096 possible levels, an analogue output can be set to 1 of 4096
values. The percentage change between adjacent digital values is

0.0244% or 244 parts per million.

Chapter 1 Page 7

AD1200 Reference Introduction

Figure 1-7. Bit Weights And Resolution.___________________________________

ЪДДДДДДВДДДДДДДДДДДВДДДДДДДДДДДВДДДДДДДДДДДДДДВДДДДДДДДД¿
³

BITS ³ STATES

³

PERCENTAGE

³

PARTS

³

DYNAMIC

³

³

³

³

³

PER MILLION

³

RANGE

³

³

n ³ 2n ³ %

³

PPM

³

dB

³
ГДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДЕДДДДДДДДД´
³

0 ³ 1

³

100

³

1,000,000

³

0.0

³
³

1 ³ 2

³

50

³

500,000

³

6.0

³
³

2 ³ 4

³

25

³

250,000

³

12.0

³
³

3 ³ 8

³

12.5

³

125,000

³

18.1

³
³

4 ³ 16

³

6.25

³

62,500

³

24.1

³
³

5 ³ 32

³

3.125

³

31,250

³

30.1

³
³

6 ³ 64

³

1.5625

³

15,625

³

36.1

³
³

7 ³ 128

³

0.78125

³

7,812.50

³

42.1

³
³

8 ³ 256

³

0.39063

³

3,906.25

³

48.2

³
³

9 ³ 512

³

0.19531

³

1,953.13

³

54.2

³
³

10 ³ 1,024

³

0.09766

³

976.56

³

60.2

³
³

11 ³ 2,048

³

0.04883

³

488.28

³

66.2

³
³

12 ³ 4,096

³

0.02441

³

244.14

³

72.3

³
ГДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДЕДДДДДДДДД´
³

13 ³ 8,192

³

0.01221

³

122.07

³

78.3

³
³

14 ³ 16,384

³

0.00610

³

61.04

³

84.3

³
³

15 ³ 32,768

³

0.00305

³

30.52

³

90.3

³
³

16 ³ 65,536

³

0.00153

³

15.26

³

96.3

³
ГДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДЕДДДДДДДДД´
³

17 ³ 131,072

³

0.00076

³

7.63

³

102.4

³
³

18 ³ 262,144

³

0.00038

³

3.82

³

108.4

³
³

19 ³ 524,288

³

0.00019

³

1.91

³

114.4

³
³

20 ³ 1,048,576

³

0.00010

³

0.95

³

120.4

³
АДДДДДДБДДДДДДДДДДДБДДДДДДДДДДДБДДДДДДДДДДДДДДБДДДДДДДДДЩ

Unipolar Vs Bipolar Voltage Ranges.________________________________

A Unipolar voltage is a positive only voltage, it can vary

between zero volts and a maximum positive value. 0 to +5V is a
typical unipolar voltage range.

A Bipolar voltage is one that can be positive or negative, it

can vary from an extreme minimum negative value, through zero
volts, up to a maximum positive value, -5V to +5V is a typical
bipolar range.

Differential Vs Single Ended Signals.________________________________

A single ended signal is where the analogue voltage is

Page 8 Chapter 1

Introduction AD1200 Reference

carried on only one wire, the analogue voltage required is the
difference between the voltage on the wire and the Analogue
Ground, that is the signal is measured with respect to the
interface cards analogue ground. The advantage of using single
ended inputs to the A/D converter is that 16 input channels are
available.

Differential signals are carried on two wires, the analogue
voltage required is the difference between the voltage on the two
wires, the signal on one of the pair of wires is measured with
respect to the ’ground’ of the other wire. The advantage of
differential inputs to the A/D converter is a significant reduction
in measured noise due to two factors, rejection of noise common
to both wires and the elimination of errors due to differences in
ground potential.

If the pair of differential signals are kept physically close
to each other then the noise effecting one wire equally effects
the other but the DIFFERENCE in voltage between the wires
remains constant, thus the noise has little or no effect on the
analogue signal. Twisted pair cables are usually used with
differential signals being transmitted any distance.

Errors in A/D measurements can arise if the earth potential
of the source of the analogue signal is different to that of the
receiver of the analogue signal. In single ended systems the
analogue voltage is referenced to AGND, the analogue ground, if
this is not exactly identical to the AGND of the source device
then systematic errors will result. Differential inputs again avoid
this error since the required analogue voltage is that dropped
across the two input wires.

The Analogue To Digital Converter._______________________________

The AD1200 series of cards are built round the Burr
Brown ADS774 and ADS574 sampling A/D converters. These
are recently introduced parts that include a sample and hold
circuit as well as an A/D converter on a 28 pin, 0.3 inch chip.
The through put and ease of application of these devices has put

Chapter 1 Page 9

AD1200 Reference Introduction

PC cards using them far ahead of any competition. The ADS574
has a conversion time of 25 microseconds and the ADS774 a
conversion time of 8 microseconds.

The AD converter takes an analog input voltage and
represents it as a 12 bit digital value. The analogue input signal
may be produced by vibration, pressure or temperature sensors
but as long as it is within +/-10 Volts the AD1200 series of
cards can convert the voltage to a 12 bit digital value. Low level
input signals can be amplified by a factor of 2, 4, 8, 10, 100 or
1000 to give 12 bit resolution from full scale signals as small as

2.5 millivolts.

The A/D system can be jumper set for 8 differential or 16
single ended input channels. It can be configured for unipolar,
positive only, inputs or bipolar, negative and positive, inputs.
The A/D conversion may be performed under programmed i/o,
interrupt driven input or via DMA, direct memory access, with
successive conversions being initiated either by the users
program, via the pacer clock or synchronised to external user
supplied signals.

Input Channel Selection.______________________

Whilst the AD1200 card has up to 16 input channels it has
only 1 A/D converter. The AD1200 series are configurable for
either 16 channels of Single Ended input, 16 channels of Pseudo
Differential Input or 8 channels of Differential Input. There is
only ONE A/D converter on the board and an analogue
multiplexer is used to route one of these 8 or 16 input channels
through the programmable gain amplifier to the A/D converter.
The analogue multiplexer is programmable, ie the input channel
is selected by the users software. Thus up to 16 voltage sources
can be permanently applied to the AD1200 series and the actual
channel to be converted be determined by the program the user
runs on the PC. The input channel is selected by writing to the
A/D Gain Channel Register, ADGCR, register 1.

When a new channel is selected the settling time to within

0.01% is 3.5 microseconds.

Page 10 Chapter 1

Introduction AD1200 Reference

Programmable Gain.___________________

Note The AD1221 and AD1220 do NOT have programmable
gain, the input gain is fixed at 1.

Before the selected input channel is routed to the A/D
converter it passes through the PGA, Programmable Gain
Amplifier. This amplifies the input signal before the conversion
process beings. The programmable gain comes in two varieties:­one for LOW input signals, eg AD1211L, that has gains of 1,
10, 100 and 1000 and one for HIGH input signals eg AD1211H,
that has gains of 1, 2, 4 and 8.

In this way input voltages from 0 to 10 Volts on one
channel and 0 to 10 milli Volts on another channel can both be
converted to a 12 bit signal resolving across their whole range.
The gain applied to the input is selected, along with the input
channel, by writing to the A/D Gain Channel Register, ADGCR,
register 1.
Programmable gain is a powerful feature enabling the AD1200
series to convert input signals of widely different levels, making
the cards very flexible and expanding the number of possible
applications vastly.

The settling time, to within 0.01%, for the programmable
gain amplifier is 2 microseconds for gains of 1, 2, 4, 8, 10 and
100 and 10 microseconds for a gain of 1000.

Thus the total over all settling, to within 0.01%, time when
both analogue multiplexer and programmable gain amp are
changed is 4 microseconds for gains 1 to 100 and 10
microseconds for a gain of 1000.

Analogue Input Ranges._____________________

The full scale analogue input ranges are set by jumpers
when the card is installed, unlike the gain applied to the signal
or the input channel routed to the A/D converter which is
software selectable. Please ensure that the GAIN and Analogue
Input Range selected do not result in off scale signals being
applied to the A/D converter. Thus when jumper set for +2.5
Volt inputs, do not use an input voltage of 10 milliVolts with a

Chapter 1 Page 11

AD1200 Reference Introduction

gain of 1000 otherwise a 10 Volt signal will be fed from the
PGA into the A/D converter, four times over scale!

Programmed I/O, Interrupts and DMA.___________________________________

The A/D conversion may be performed under programmed

i/o, interrupt driven input or via DMA, direct memory access.

Programmed I/O.________________

In programmed i/o mode, the user’s program initiates an
A/D conversion and then monitors the A/D Done bit, register 0
bit 7, waiting until it is set. This indicates that the conversion
has been completed and the digitised value of the input voltage
is waiting to be read from the ADCLO and ADCHI input
registers. Having read the contents of these registers, low byte
first and high byte last, thus clearing the A/D Done bit, the next
A/D conversion may be performed.

Programmed i/o is also known as ’polled i/o’ since the
user has to constantly poll the converter status bits to see if it is
done.

The users software, built from the Real World driver, thus
starts, tests for, and services each conversion. Though
programmed i/o is easily understood, the PC and the program
are consumed by the process of performing the A/D conversions.
Thus programmed i/o is used for single conversions or low
sample rate continuous conversions.

Interrupt Driven I/O.___________________

In interrupt driven mode, after interrupts are enabled and
the start of the first conversion has been triggered, when the
conversion is done, the A/D Done bit is set and this
automatically causes a hardware interrupt which makes the
computer execute an ISR, interrupt service routine. The interrupt
service routine reads the ADCLO and then the ADCHI input
registers and stores the data in memory. When enough
conversions have taken place, the interrupt service routine
disables A/D interrupts and if necessary stops the pacer clock.

Page 12 Chapter 1

Introduction AD1200 Reference

The users software, built from the Real World driver, thus
sets up the interrupt hardware, starts the first conversion. The
separate ISR services each conversion whenever it happens and
finally disables the conversion. In between conversions the PC
and the program are free to perform other tasks, eg updating a
graph on the screen.

Thus interrupt driven i/o is used for medium sample rate
continuous conversions or when continuous conversions across
over several inputs channels and gain combinations are required.

DMA, Direct Memory Access.__________________________

In DMA, direct memory access, mode, the DMA controller
is programmed with the number of conversions to be taken,
DMA is enabled and the start of the first conversion is triggered.
When the conversion is done, the A/D Done bit is set and this
automatically commences a DMA input cycle. The DMA
controller reads the ADCLO and then the ADCHI input registers
placing the data straight into memory without the help of the
computers micro processor. When the last of the conversions
takes place, the DMA controller sets the TC line true when
reading the ADCHI byte thus disabling further A/D conversions
and, if necessary, stopping the pacer clock.

The users software, built from the Real World driver, thus
merely sets up the DMA hardware and starts the first
conversion. From then on till the last conversion takes place the
PC and the program are completely free to perform other tasks,
eg updating a graph on the screen.

Thus DMA driven i/o is used for the maximum rate
continuous conversions but only with a single channel/gain
combination.

The Pacer Clock._______________

The pacer clock can be used to trigger the A/D converter
thus forcing the start of conversion to be at precisely timed
intervals. When the clock is enabled the users program is not
only relieved of the burden of determining WHEN to start the

Chapter 1 Page 13

AD1200 Reference Introduction

next conversion but also the burden OF starting the conversion.

In addition, input signals can be regularly sampled at
known intervals thus providing information not only about the
magnitude of the input but also about how it changes with time.
The pacer clock allows pipelining of successive A/D
conversions, this concept is explained below.

The timer circuitry can be programmed to select either the
on board 600kHz oscillator or an external, user supplied, TTL
clock as fundamental frequency for the pacer clock. The timer
register can be programmed to select 1 of 57 different factors by
which to divide the fundamental frequency to produce the
resulting pacer clock signal.

This pacer clock signal is used mainly as a strobe to force
A/D conversions but can also be used in the top of range
AD1200 card to strobe data into either D/A converter and in or
out of the TTL compatible digital ports.

A/D Throughput and Pipelining.____________________________

The throughput of the A/D converter is how many
conversions can be performed within a given period of time.
The raw A/D conversion time, 25 microseconds for the AD1221
& AD1211 cards and 8 microseconds for the AD1220, AD1210
& AD1200 cards, places the fundamental limit on how many
conversion can be performed in one second. The settling time of
the analogue input multiplexer, when the channel selected for
conversion is changed, and the settling time of the programmable
gain amplifier, when a new gain is selected, are also a factor.
However, a great consideration is the method used to transfer the
data from the card into the PC.

From the above discussions about programmed I/O,
interrupts, DMA and the use of the pacer clock it is apparent
that the slowest method of taking A/D readings is programmed
i/o. This method also has the disadvantage of requiring the most
work from the user when writing programs. The processing
power of the PC is of great importance and a 4.77MHz 8086 PC

Page 14 Chapter 1

Introduction AD1200 Reference

will perform considerably worse than a 50MHz 486. The
efficiency of the code plays an important part in throughput
especially in the slower computers. In general it is almost
impossible to exceed 30,000 A/D conversion samples a second.

With the interrupt driven i/o, the time taken by the PC to
service the interrupt becomes the critical factor. Thus this part of
the software should merely increment a pointer to memory, read
the ADCLO and then ADCHI registers, then write the resulting
data word to the memory, select the next A/D channel and gain,
trigger the A/D converter to start the next conversion and finally
exit. The time taken for the PC to branch to this interrupt
service routine, perform it and return to its original task is,
again, a function of the PC’s clock speed and the size and
efficiency of the code written. The 2k FIFO on the AD1200
overcomes this difficulty and allows 100kHz sampling!

With DMA, the data from A/D converter is moved by the
DMA controller directly into the PC’s memory, and the PC’s
own processing power is unimportant, and the throughput of the
converter is at its maximum ie 30kHz for AD1221 and AD1211
or 100kHz for AD1220, AD1210 and AD1200.

For the higher A/D throughputs with interrupts or DMA
the pacer clock has to be used.

The pacer clock allows pipelining to be used. Pipelining is
when the NEXT conversion is taking place BEFORE the
previous one has been read. IE the next conversion is put into
the pipe before the previous one is taken out. This allows the
A/D converter to be constantly acquiring & converting inputs.
The data from the A/D converter can be read during the time
between successive conversions. It is necessary that an overrun
does not take place where the NEXT conversion is finished
BEFORE the previous conversion has been read. The circuitry in
the AD1200 series of cards is designed to make efficient use of
the Pipelining concept. Modes 1, 2 and 3 use the pacer clock to
pipeline the A/D conversions. The A/D Error bit will be set by
an A/D data overrun & the pacer clock will be stopped.

Chapter 1 Page 15

AD1200 Reference Introduction

A/D Operating Modes.____________________

The whole of the AD1200 range can be programmed to
perform its A/D conversions using one of four modes. These
modes select between single conversion or continuous
conversions, choose whether the continuous conversions should
be paced via the built in 600kHz oscillator or via an external
user supplied clock and determine what starts the pacer clock
running.

Figure 1-8. Mode 0 & 1 Bits._________________________

ЪДДДДДДДДДДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

A/D Control Status Reg

³

Bits 6 & 7, XMODE, in TIMER register=0

³
ГДДДДДДВДДДДДДДВДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

MODE

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ADCSR

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ADCSR

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FUNCTION

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BITý1

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BITý0

ý³

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³

0

ýý³ý

0

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0

ýý³

Single A/D Conversion when ADGCR

³
³

³ ³ ³ A/D Gain/Channel Register, is written.

³
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³

1

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Continuous A/D conversions by pacer clock

³
³

³ ³ ³ using on board 600kHz oscillator.

³
³

³ ³ ³ Clock started when ADGCR is written.

³
ГДДДДДДЕДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

2

ýý³ý

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0

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Continuous A/D conversions by pacer clock

³
³

³ ³ ³ using on board 600kHz oscillator.

³
³

³ ³ ³ Clock started by Ext Trigger -ve edge.

³
ГДДДДДДЕДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

3

ýý³ý

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0

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Continuous A/D conversions by pacer clock

³
³

³ ³ ³ using on External Clock.

³
³

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³
АДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

The mode select determines the source of the A/D
STROBE, this is the signal that forces the A/D converter to
START performing its next conversion.

Whether Interrupts or DMA transfers occur on A/D
conversion Done depends on the setting of the INTERRUPT
ENABLE and DMA ENABLE bits in the ADCSR, the A/D
Control Status Register, register 0.

Page 16 Chapter 1

Introduction AD1200 Reference

Figure 1-9. Extended Mode Bits.____________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

TIMER Extended Mode Bits AD1200 Card Only

ээээээээ³
ГДДДДДДДВДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

BITý7

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BITý6

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Continuous Conversion Performed On

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

0

ýý³ý

0

ýý³

A/D Converter Compatible Mode

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

0

ýý³ý

1

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DAC0

³
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³

1

ýý³ý

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DAC1

³
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³

1

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1

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DIGITAL I/O PORT

³
АДДДДДДДБДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

The AD1200 card only has the ability to use the DAC0,
DAC1, DIGIN and DIGOUT ports with interrupt driven or
DMA outputs modes. The XMODE bits in the TIMER register
can be set to select one of these ports instead of the ADC
converter to be strobed by the pacer clock. The A/D modes are
selected when bits 6 & 7 of the TIMER register are both 0.

A/D Modes 0, 1, 2 & 3.____________________

Mode 0, Single Conversions._________________________

In Mode 0, each write to the ADGCR, the A/D Gain
Channel Register, register 1, generates an A/D strobe. The
following method should be used.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 00, ie Mode 0.

This stops the pacer clock if it is running.
ii) The channel and gain required is written into the ADGCR,

A/D Gain Channel register, register 1. This generates an

A/D strobe so starting an A/D conversion.
iii) When the A/D Done bit is set the ADCLO and and then

the ADCHI data bytes may be read, either by programmed

i/o, an interrupt service routine or by the DMA controller.
iv) The next A/D conversion may be started by generating an

A/D strobe by writing a new gain and channel to the

ADGCR register.

Chapter 1 Page 17

AD1200 Reference Introduction
Mode 1, Continuous Conversions, Internal Trigger & Clock.____________________________________________________

In Mode 1, the pacer clock generates each A/D strobe, the
clock is started, triggered, by a write to the ADGCR, the A/D
Gain Channel Register, register 1. The following method should
be used.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 01, ie Mode 1.

This stops the pacer clock if it is running.
ii) The pacer clock divisor, determining the frequency of the

pacer clock strobes, is written to the TIMER register. Bits

6 & 7 must be zero in the AD1200 card.
iii) The channel and gain required is written into the ADGCR,

A/D Gain Channel register, register 1. This starts the pacer

clock running. The first A/D strobe is generated one clock

period later.
iv) When the A/D Done bit is set the ADCLO and then the

ADCHI data bytes may be read, either by programmed i/o,

an interrupt service routine or by the DMA controller.
v) A/D Strobes will be automatically generated by the pacer

clock at the chosen rate, based on the 600kHz oscillator,

until the clock is stopped by a write to the ADCSR or,

when using DMA, terminal count is reached.

Mode 2, Continuous Conversions, Ext Trig, Internal Clock.___________________________________________________

In Mode 2, the pacer clock generates each A/D strobe, the
clock is started, triggered, by a user supplied negative edge on
the external trigger input line. The following method should be
used. Mode 2 allows external devices to initiate a series of
conversions.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 02, ie Mode 2.

This stops the pacer clock if it is running.
ii) The pacer clock divisor, determining the frequency of the

pacer clock strobes, is written to the TIMER register. Bits

6 & 7 must be zero in the AD1200 card.
iii) The channel and gain required is written into the ADGCR,

A/D Gain Channel register, register 1.
iv) A negative edge on the user supplied external trigger input,

Page 18 Chapter 1

Introduction AD1200 Reference

IDC connector pin 49, starts the pacer clock running. The
first A/D strobe is generated one clock period later.

v) When the A/D Done bit is set the ADCLO and ADCHI

data bytes may be read, either by programmed i/o, an
interrupt service routine or by the DMA controller.

vi) A/D Strobes will be automatically generated by the pacer

clock at the chosen rate, based on the 600kHz oscillator,
until the clock is stopped by a write to the ADCSR or,
when using DMA, terminal count is reached.

Mode 3, Continuous Conversions, External Trigger & Clock._____________________________________________________

In Mode 3, the pacer clock generates each A/D strobe, the
clock is started, triggered, by a user supplied negative edge on
the external trigger input line. The fundamental frequency of the
the pacer clock is derived from a user supplied external clock,
on IDC Connector pin 50. The following method should be used.
Mode 3 allows the a series of conversions to be synchronised
with external events or to an external device.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 03, ie Mode 3.

This stops the pacer clock if it is running.
ii) The pacer clock divisor, determining the frequency of the

pacer clock strobes, is written to the TIMER register. Bits

6 & 7 must be zero in the AD1200 card.
iii) The channel and gain required is written into the ADGCR,

A/D Gain Channel register, register 1.
iv) A negative edge on the user supplied external trigger input,

IDC connector pin 49, starts the pacer clock running. The

first A/D strobe is generated one clock period later.
v) When the A/D Done bit is set the ADCLO and then the

ADCHI data bytes may be read, either by programmed i/o,

an interrupt service routine or by the DMA controller.
vi) A/D Strobes will be automatically generated by the pacer

clock at the chosen rate, based on the user supplied

external clock input, until the clock is stopped by a write

to the ADCSR or, when using DMA, terminal count is

reached.

Chapter 1 Page 19

AD1200 Reference Introduction

The Analogue To Digital Converter._______________________________

The AD1200 series of cards use two completely

independent Burr Brown DAC667 D/A converters.

The D/A converter takes a 12 bit digital input code and

turns it into an analogue output voltage.

Each DAC can be configured for unipolar, positive only,

0~10V and 0~5V outputs or bipolar, negative and positive, ±10V,
±5V and ±2.5V outputs.

D/A Programmed I/O.____________________

The D/A conversion are usually performed using
programmed i/o, the 12 bit output is written lower 8 bits first to
the DACLO register and then the upper 4 bits to the DACHI
register. When the DACHI register is written the digital to
analogue conversion takes place.

D/A Interrupts and DMA. AD1200 Card Only._______________________ __________________

The AD1200 card only has the ability to use interrupt
driven or DMA outputs modes to the D/A converters.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 01, 02 or 03, ie Mode

1, 2 or 3.

This stops the pacer clock if it is running.
ii) The XMODE bits in the TIMER register is set to either to

40 hex to select DAC0 or 80 hex to select DAC1 as the

recipient of the interrupt or DMA data, at the same time,

the pacer clock source and divisor is selected, determining

the frequency of the pacer clock strobes.
iii) The initial DAC data values are written to DACLO and

DACHI. Writing to the DACLO or DACHI registers does

not cause a D/A conversion when the extended mode bits

are set to 40 or 80 hex. Instead the conversion is caused

by the strobe signals from the pacer clock.
iv) A write to the ADGCR register or an negative edge on the

external trigger input starts the pacer clock as selected by

the ADCSR Mode bits.
v) DAC conversion strobes will be automatically generated by

Page 20 Chapter 1

Introduction AD1200 Reference

the pacer clock at the chosen rate, based on the 600kHz
oscillator or external clock input as selected by the
ADCSR Mode bits.
The pacer clock strobes the converters at precisely timed
intervals. The pacer clock also causes an interrupt or DMA
cycle which then updates the DACLO and DACHI
registers ready for the next pacer clock strobe.

vi) When the required number of conversion has taken place

the pacer clock is stopped either by the interrupt service
routine or by the DMA TC, terminal count signal.
The clock may also stopped by a write to the ADCSR.

Digital I/O Ports._______________

The digital input port is an 8 bit LS TTL compatible port,

it is a read only port.

The digital output port is an 8 bit LS TTL compatible port,

it is a write only port.

Digital Port Programmed I/O.__________________________

Digital i/o is usually performed using programmed i/o. As
the data is written to the digital output register the bit pattern
immediately appears on the digital output pins. A read of the
digital input register latches the current bit pattern present on the
digital input pins returning it as an 8 bit data byte.

Digital Port Interrupts and DMA. AD1200 Card Only.______________________________ __________________

The AD1200 card only has the ability to use the digital
input and output port in interrupt driven or DMA modes. The
mode bits in the ADCSR in conjunction with bits 6 & 7 in the
TIMER register are used to specify the digital port, instead of
the A/D converter, as the target for the pacer clock strobes.
i) The mode bits in the ADCSR, A/D Control Status

Register, register 0, should be set to 01, 02 or 03, ie Mode

1, 2 or 3.

This stops the pacer clock if it is running.
ii) The XMODE bits in the TIMER register is set to C0 hex

Chapter 1 Page 21

AD1200 Reference Introduction

selecting the digital i/o ports instead of the ADC as the
recipient of the interrupt or DMA data, at the same time,
the pacer clock source and divisor is selected, determining
the frequency of the pacer clock strobes.

iii) A write to the ADGCR register or an negative edge on the

external trigger input starts the pacer clock as selected by
the ADCSR Mode bits.

iv) DIG strobes will be automatically generated by the pacer

clock at the chosen rate, based on the 600kHz oscillator or
external clock input as selected by the ADCSR Mode bits.
The pacer clock strobe causes an interrupt or DMA cycle
which then updates the DIGIN or DIGOUT registers ready
for the next pacer clock strobe.

v) When the required number of conversion has taken place

the pacer clock is stopped either by the interrupt service
routine or by the DMA TC, terminal count signal.
The clock may also stopped by a write to the ADCSR.

Screw Terminal Board._____________________

The easiest and tidiest way to connect your i/o card to

your rig is via the Analogue Screw Terminal Board, ATB.

The Screw Terminal Board converts from 50 IDC ribbon

to screw terminals. The screw terminals can take wire up to

2.5mm, 0.1 inch diameter. The 50IDC entry is a latching
connector to ensure hold fast connections.

Power taken from the PC via at ±12Volts is fed through

power on indicator LEDs and decoupling capacitors.

There is provision for an optional 4-20mA conversion form

both DAC analogue output signals.

There is provision for an optional 4-20mA conversion to

the analogue voltage input channels of the A/D converter.

Each screw terminal, is clearly identified by IDC pin
number, and AD1200 signal name.
The analogue and digital grounds are kept separate.
The digital i/o lines can also take an optional LED to show
signal logic state.

A handy cable grip clamps the wires to ensure a robust,

Page 22 Chapter 1

Introduction AD1200 Reference

tidy layout. Order one now!
Part number:
ATB Analogue Screw Terminal Board.
ATB 4-20Xmtr 4-20mA Transmitter option for the terminal

board.

ATB 4-20Rxvr 4-20mA Receiver option for the terminal board.

4-20mA Current Conversion Options._________________________________

The primary reason for for using 4-20mA currents in the
transmission of analogue signals is because currents can be sent
a long way without loss and without being greatly degraded by
noise. When voltages are being transmitted over anything but
very short lengths the resistance in the cables leads to a drop in
the received signal, some voltage is dropped across the cable
itself. However, due to the law of conservation of current,
currents can be transmitted without loss.

Chapter 1 Page 23

AD1200 Reference Installation Guide

CHAPTER 2

PC AD1200

INSTALLATION

GUIDE.

Introduction.____________

This chapter explains how to configure and install the PC
AD1200 board into a PC compatible computer. Detailed
instructions are given how to set the i/o address select DIP
switches as well as how to set the IRQ, DMA jumper blocks. In
addition, the jumpers configuring the Analogue to Digital input
and the two Digital to Analogue outputs are explained.
Finally details of how to connect up the AD1200 to the users
own system are given.

If the PC AD1200 is to be installed in another make of PC
then it may be necessary to consult the instructions included in
that PC’s documentation.

The two third size PC AD1200 board will fit into both
long or a short slots, it can be placed in standard 8 bit PC slots
or in the longer 16 bit AT slots.

If you have a Micro Channel Architecture computer such
as the IBM PS/2 Models 50-90 then you require our PS AD1200
card instead.

Configuring The PC AD1200 Board.________________________________

In the state it leaves our factory, the PC AD1200 Interface
Board is ready to plug straight into an IBM PC computer.

So, unless you have GOOD REASON, you do not need
to alter its default setting.

However, due to the large variety of add-on boards that

Page 24 Chapter 2

Installation Guide AD1200 Reference

may be present in the PC, your PC AD1200 board may need
adjusting to suit your setup. The seven configurable options are
factory set to following defaults.

Default Settings.

I/O address: 0218 Hex. 8 bytes of i/o 0218-021F hex.
Interrupt Jumper: IRQ7.
DMA Jumper: DMA1. AD1200 Only!
DAC0 settings: -5 to +5 Volts BIPOLAR output.
DAC1 settings: -5 to +5 Volts BIPOLAR output.
ADC settings: 16 Channels of Single Ended,

-5 to +5 Volts BIPOLAR input.

Figure 2-1. AD1200 Card Layout._____________________________

æ

DAC1

æ

DAC0

æ

ADC

æ

ADC 20Vin

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³ ЫююЫЫ ЫююЫЫ ÛþÛþ

ß ³ÚÄ

³

-5/+5V -5/+5V -5/+5V

³³

³

BIPOLAR BIPOLAR BIPOLAR

ÚÄij³Ä¿

³

OUTPUT OUTPUT INPUT

юЫЫююЫ ³ ³³

50

³ å

16 SE INPUTS

³³³

WAY

³ ³³³
³

³³³

C

³

123456

³³³

A

³ жжееее ³ ³³

B

³

1111 I/O ADDR 0218Hex

³³³

L

³

5210234657

³³³

E

³

юююююююююЫ

ЫЫюююю ÀÄij³ÄÙ

АДДДДДДДДДДДДДДДДДДДДДДД¿

Ú¿

IRQ7 å

åå

DMA1

ÚÄÄÙ³

АДДДДЩАДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ ³

Chapter 2 Page 25

AD1200 Reference Installation Guide

Figure 2-2. AD1210 AD1211 Card Layout._____________________________________

æ

DAC1

æ

DAC0

æ

ADC

æ

ADC 20Vin

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³ ЫююЫЫ ЫююЫЫ ÛþÛþ

ß ³ÚÄ

³

-5/+5V -5/+5V -5/+5V

³³

³

BIPOLAR BIPOLAR BIPOLAR

ÚÄij³Ä¿

³

OUTPUT OUTPUT INPUT

юЫЫююЫ ³ ³³

50

³ å

16 SE INPUTS

³³³

WAY

³ ³³³
³

I/O ADDR

³³³

C

³

123456 8254=210h

³³³

A

³ жееееж ³ ³³

B

³

8254 Counter Timer 1111 AD1210/11=0218Hex

³³³

L

³ Û

. OUT0 Not Connected 5210234567

³³³

E

³ å

To Output PIN36

юююююююююЫ ÀÄij³ÄÙ

АДДДДДДДДДДДДДДДДДДДДДДД¿

Ú¿

IRQ7

å ÚÄÄÙ³

АДДДДЩАДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ ³

Figure 2-3. AD1220 AD1221 Card Layout._____________________________________

æ

DAC1

æ

DAC0

æ

ADC

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³ ЫююЫЫ ЫююЫЫ ÛþÛþ þÛ

ADC INPUT

³ÚÄ

³

-5/+5V -5/+5V -5/+5V GAIN SELECT

³³

³

BIPOLAR BIPOLAR BIPOLAR

ÚÄij³Ä¿

³

OUTPUT OUTPUT INPUT

юЫЫююЫ ³ ³³

50

³ å

16 SE INPUTS

³³³

WAY

³ ³³³
³

I/O ADDR

³³³

C

³

123456 8254=210h

³³³

A

³ жееееж ³ ³³

B

³

8254 Counter Timer 1111 AD1220/21=0218Hex

³³³

L

³ Û

. OUT0 Not Connected 5210234567

³³³

E

³ å

To Output PIN36

юююююююююЫ ÀÄij³ÄÙ

АДДДДДДДДДДДДДДДДДДДДДДД¿

Ú¿

IRQ7

å ÚÄÄÙ³

АДДДДЩАДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ ³

Setting The PC AD1200 I/O Address.________________________________

The AD1200 card has one 6 way DIP Address select
switch block, the AD1210/11 1220/21 have one 8 way DIP
Address select switch block. By referring to the PC AD1200
card locate the I/O Address DIP switches right of the the centre
of the board.

The factory set address, 0218H, is shown in Figure 2-4 (a)
and (b). If you need to run the board at a different address then

Page 26 Chapter 2

Installation Guide AD1200 Reference

set the DIP switches according to Figure 2-7.

The PC AD1200 board can reside at any address on an 8
byte boundary within the range 0200H-03F8H, giving the 64
possible combinations.

The AD1210/11 and AD1220/21 boards occupy 16 bytes of
i/o address space and can be set to reside at one of 48 base
addresses within the range 0100H-03F0H. The DIP switches 1-7
control the PC AD1200 card i/o base address select, DIP switch
1-7 correspond to the A3-A9 address lines, respectively. DIP 8
does not have any effect and is a "don’t care" switch, for
compatibility with future versions of the AD1200 card leave DIP
8 off.
Only those addresses in the range 0100 - 03FF hex, in Figure 2­7 below, are available for use since addresses in the range 0000­00FF hex are reserved for system mother board devices such are
DMA circuitry, keyboard i/o etc.

The best address range for the AD1200 card is in the 0200
hex -023F hex & 0280 hex - 02BF hex ranges which are usually
unused.

A list of i/o addresses to be avoided, depending on what options
are installed in the PC, is given in Figure 2-5.

Figure 2-4a. AD1200 Factory Set DIP Switches._________________________________________

DIP 1-6 I/O Address select

ЪДВДВБВДВД¿
³ý³ý³ý³ý³ý³

å

on

ЪДДДДДД¿
³жжееее³

æ

off

³

123456

³

АДДДДДДЩ

PC AD1200 Factory Set Default Address= 0218 Hex, 536 Decimal

using 8 bytes of i/o space 0218-021F hex

Chapter 2 Page 27

AD1200 Reference Installation Guide

Figure 2-4b. AD1210-21 Factory Set DIP Switches.____________________________________________

DIP 1-6 I/O Address select

ЪДВДЕДВД¿
³ý³ý³ý³

³

å

on

ЪДДДДДД¿
³жееееж³

æ

off

³

123456

³

АДДДДДДЩ

8254 Counter Timer Address = 0210 Hex, 528 Decimal

PC AD1210-21 Factory Set Default Address = 0218 Hex, 536 Decimal

using total 16 bytes of i/o space 0210-021F hex

Figure 2-5. I/O Addresses To Avoid._______________________________

I/O ADDRESS NORMAL USE.___________ ___________
01F0H- 01F7H Fixed Disk Controller #1 for AT/386/486
0201H- 0201H Game Control Adapter
0218H- 021FH *** PC AD1200 Board
0278H- 027FH *** Second Printer Port Adapter
02E1H *** PC ELITE IEEE Board.
02E1H IBM/ National Instruments IEEE card.
02F8H- 02FFH *** Second Serial Port Adapter
0300H- 0307H *** PC Proto card
0300H- 0303H *** PC IEEE Board
0300H- 0303H *** PC DIO24 Board
0308H- 030FH *** PC DIO48 Board
0310H- 031FH *** PC Timer-DIO Board
0320H- 032FH Hard Disk
0340H- 0360H *** PC DIO192 Board
0360H- 036FH PC Network
0378H- 037FH *** Printer Port Adapter
0380H- 038CH S.D.L.C. Communications
03A0H- 03A9H Primary Binary Sync Comms
03B0H- 03BFH Monochrome Display and Printer Card
03C0H- 03CFH Enhanced Graphics Adapter Extra I/O
03D0H- 03DFH Colour Graphics Adapter
03F0H- 03F7H 5.25 inch Disk Drive Adapter
03F8H- 03FFH *** Serial Port Adapter
*** These cards available from us.

Page 28 Chapter 2

Installation Guide AD1200 Reference

The i/o addresses that are likely to be good for the PC
AD1200 are shown in Figure 2-6. However, we cannot guarantee
that they are not already in use by some other adapter that may
be installed in your PC.

Figure 2-6. Likely I/O Address.___________________________

I/O ADDRESS NORMAL USE.___________ ___________
0204H- 0277H Unused.
0280H- 02BFH Unused.
02C8H- 02DFH Unused.
02E4H- 02F7H Unused.
0300H- 031FH Unused.
0330H- 035FH Unused.
0380H- 03AFH Unused Usually.
03E0H- 03EFH Unused.

If in doubt check the manuals of any adapters installed.

Figure 2-7a. AD1200 Base Addresses.________________________________

DIP1 DIP2 DIP3 DIP4 DIP5 DIP6 Base Address Of Card____ ____ ____ ____ ____ ____ ____________________
Off Off Off Off Off Off 03F8 Hex 1016 Dec
On Off Off Off Off Off 03F0 Hex 1008 Dec
Off On Off Off Off Off 03E8 Hex 1000 Dec
On On Off Off Off Off 03E0 Hex 992 Dec

Off Off On Off Off Off 03D8 Hex 984 Dec
On Off On Off Off Off 03D0 Hex 976 Dec
Off On On Off Off Off 03C8 Hex 968 Dec
On On On Off Off Off 03C0 Hex 960 Dec

Off Off Off On Off Off 03B8 Hex 952 Dec
On Off Off On Off Off 03B0 Hex 944 Dec
Off On Off On Off Off 03A8 Hex 936 Dec
On On Off On Off Off 03A0 Hex 928 Dec

Off Off On On Off Off 0398 Hex 920 Dec
On Off On On Off Off 0390 Hex 912 Dec

Chapter 2 Page 29

AD1200 Reference Installation Guide

Off On On On Off Off 0388 Hex 904 Dec
On On On On Off Off 0380 Hex 896 Dec

Off Off Off Off On Off 0378 Hex 888 Dec
On Off Off Off On Off 0370 Hex 880 Dec
Off On Off Off On Off 0368 Hex 872 Dec
On On Off Off On Off 0360 Hex 864 Dec

Off Off On Off On Off 0358 Hex 856 Dec
On Off On Off On Off 0350 Hex 848 Dec
Off On On Off On Off 0348 Hex 840 Dec
On On On Off On Off 0340 Hex 832 Dec

Off Off Off On On Off 0338 Hex 824 Dec
On Off Off On On Off 0330 Hex 816 Dec
Off On Off On On Off 0328 Hex 808 Dec
On On Off On On Off 0320 Hex 800 Dec

Off Off On On On Off 0318 Hex 792 Dec
On Off On On On Off 0310 Hex 784 Dec
Off On On On On Off 0308 Hex 776 Dec
On On On On On Off 0300 Hex 768 Dec

Off Off Off Off Off On 02F8 Hex 760 Dec
On Off Off Off Off On 02F0 Hex 752 Dec
Off On Off Off Off On 02E8 Hex 744 Dec
On On Off Off Off On 02E0 Hex 736 Dec

Off Off On Off Off On 02D8 Hex 728 Dec
On Off On Off Off On 02D0 Hex 720 Dec
Off On On Off Off On 02C8 Hex 712 Dec
On On On Off Off On 02C0 Hex 704 Dec

Off Off Off On Off On 02B8 Hex 696 Dec
On Off Off On Off On 02B0 Hex 688 Dec
Off On Off On Off On 02A8 Hex 680 Dec
On On Off On Off On 02A0 Hex 672 Dec

Page 30 Chapter 2

Installation Guide AD1200 Reference

Off Off On On Off On 0298 Hex 664 Dec
On Off On On Off On 0290 Hex 656 Dec
Off On On On Off On 0288 Hex 648 Dec
On On On On Off On 0280 Hex 640 Dec

Off Off Off Off On On 0278 Hex 632 Dec
On Off Off Off On On 0270 Hex 624 Dec
Off On Off Off On On 0268 Hex 616 Dec
On On Off Off On On 0260 Hex 608 Dec

Off Off On Off On On 0258 Hex 600 Dec
On Off On Off On On 0250 Hex 592 Dec
Off On On Off On On 0248 Hex 584 Dec
On On On Off On On 0240 Hex 576 Dec

Off Off Off On On On 0238 Hex 568 Dec
On Off Off On On On 0230 Hex 560 Dec
Off On Off On On On 0228 Hex 552 Dec
On On Off On On On 0220 Hex 544 Dec

Off Off On On On On 0218 Hex 536 Default___ ___ __ __ __ __ ________ ___________
On Off On On On On 0210 Hex 528 Dec
Off On On On On On 0208 Hex 520 Dec
On On On On On On 0200 Hex 512 Dec.

Figure 2-7b. AD1210-21 Base Addresses.___________________________________

The 8254 counter timer occupies the lower 8 i/o address.
The PCAD1200 occupies the upper 8 i/o address.
DIP1 DIP2 DIP3 DIP4 DIP5 DIP6 8254 AD1210/21____ ____ ____ ____ ____ ____ ____ _________
Off Off Off Off Off Off 03F0 03F8 Hex
On Off Off Off Off Off 03E0 03E8 Hex
Off On Off Off Off Off 03D0 03E8 Hex
On On Off Off Off Off 03C0 03E8 Hex

Off Off On Off Off Off 03B0 03B8 Hex
On Off On Off Off Off 03A0 03A8 Hex
Off On On Off Off Off 0390 0398 Hex

Chapter 2 Page 31

AD1200 Reference Installation Guide

On On On Off Off Off 0380 0388 Hex

Off Off Off On Off Off 0370 0378 Hex
On Off Off On Off Off 0360 0368 Hex
Off On Off On Off Off 0350 0358 Hex
On On Off On Off Off 0340 0348 Hex

Off Off On On Off Off 0330 0338 Hex
On Off On On Off Off 0320 0328 Hex
Off On On On Off Off 0310 0318 Hex
On On On On Off Off 0300 0308 Hex

Off Off Off Off On Off 02F0 02F8 Hex
On Off Off Off On Off 02E0 02E8 Hex
Off On Off Off On Off 02D0 02D8 Hex
On On Off Off On Off 02C0 02C8 Hex

Off Off On Off On Off 02B0 02B8 Hex
On Off On Off On Off 02A0 02A8 Hex
Off On On Off On Off 0290 0298 Hex
On On On Off On Off 0280 0288 Hex

Off Off Off On On Off 0270 0278 Hex
On Off Off On On Off 0260 0268 Hex
Off On Off On On Off 0250 0258 Hex
On On Off On On Off 0240 0248 Hex

Off Off On On On Off 0230 0238 Hex
On Off On On On Off 0220 0228 Hex
Off On On On On Off 0210 0218 Hex Default___ __ __ __ __ ___ ____ ________ _______
On On On On On Off 0200 0208 Hex

Off Off Off Off Off On 01F0 01F8 Hex
On Off Off Off Off On 01E0 01E8 Hex
Off On Off Off Off On 01D0 01D8 Hex
On On Off Off Off On 01C0 01C8 Hex

Off Off On Off Off On 01B0 01B8 Hex

Page 32 Chapter 2

Installation Guide AD1200 Reference

On Off On Off Off On 01A0 01A8 Hex
Off On On Off Off On 0190 0198 Hex
On On On Off Off On 0180 0188 Hex

Off Off Off On Off On 0170 0178 Hex
On Off Off On Off On 0160 0168 Hex
Off On Off On Off On 0150 0158 Hex
On On Off On Off On 0140 0148 Hex

Off Off On On Off On 0130 0138 Hex
On Off On On Off On 0120 0128 Hex
Off On On On Off On 0110 0118 Hex
On On On On Off On 0100 0108 Hex

If you have set the board at a different address then you
will need to inform the software that you intend to run about the
new i/o address.

Using More Than One PC AD1200 Board._____________________________________

Since each PC AD1200 card, can measure up to 16
Analogue inputs and drive 2 analogue outputs, with 8 digital i/p
and 8 digital output lines it is not generally necessary to have
more than one board installed in the PC at any one time.
However, it is possible to have many AD1200 cards, each
controlling its own set of i/o lines, in one PC.

The golden rule to follow to allow this is:- Ensure that each
PC AD1200 card is set to a different i/o address. If more
than one card is performing interrupt or DMA driven i/o
then set the IRQ and DMA jumpers to different channels.

Interrupt Selection._________________

The AD1200 card can produce interrupts due to a range of
circumstances, pacer controlled A/D conversion done, pacer

Chapter 2 Page 33

AD1200 Reference Installation Guide

controlled D to A converter timed out, pacer controlled digital
i/o timed out etc. The appropriate signal must be enabled in
software and the irq signal generated must be physically
connected to one of the processor Interrupt ReQuest lines by
placing the jumper on the IRQ block in the correct place.

The PC AD1200 has 1 IRQ jumper block labelled
IRQJMP. The position of the jumper MUST match the IRQ
level set in the software.

Setting The Interrupt Jumper Block.________________________________

The PC AD1200 has 1 IRQ jumper block, IRQJMP

The movable jumper on the jumper block is used to
specify which hardware interrupt, into the computer, is to be
generated by the PC AD1200 card. The position of the jumper
MUST match the IRQ level set in the your software. Remember
to enable the IRQ DIP switch.

Most users will not require IRQs and so should leave the
IRQ jumper in the factory set position, IRQ 7.

NOTE: Do not add an extra jumper of your own across the

_________

jumper block it will only cause great confusion.

Page 34 Chapter 2

Installation Guide AD1200 Reference

Figure 2-8. The IRQ Jumper Block._______________________________

NORMAL USE OF INTERRUPT.________________________

ЪДДДДДДДДДД¿
³ююююЫююююю³

IRQ2 E.G.A. GRAPHICS CARD.

АДДДДДДДДДДЩ

Good choice.

ЪДДДДДДДДДД¿
³юююююЫюююю³

IRQ3 RS232C COM PORTS 2-8.

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³ююююююЫююю³

IRQ4 RS232C COM PORT 1.

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³юююююююЫюю³

IRQ5 HARD DISK IN XT, OK in 286/386/486

АДДДДДДДДДДЩ

Good choice.

ЪДДДДДДДДДД¿
³ююююююююЫю³

IRQ6 DISK DRIVE STATUS.

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³юююююююююЫ³

IRQ7 PRINTER. PC AD1200 Recommended.

АДДДДДДДДДДЩ

DEFAULT.

ЪДДДДДДДДДД¿
³юююЫюююююю³

IRQ10 Usually Free, Good Choice

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³ююЫююююююю³

IRQ11 Usually Free, Good Choice

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³юЫюююююююю³

IRQ12 Usually Free, Good Choice

АДДДДДДДДДДЩ
ЪДДДДДДДДДД¿
³Ыююююююююю³

IRQ15 Usually Free, Good Choice

АДДДДДДДДДДЩ

DMA Selection. AD1200 Only.______________ _____________

The AD1200 card can perform its input or output under

DMA control, that is the data moves between the PC and the

Chapter 2 Page 35

AD1200 Reference Installation Guide

converter in the background whilst the computer is apparently
busy doing another job. DMA is ideal for moving large amounts
of data very quickly. The DMA hardware requires that the DMA
channel jumper settings should be set for DMA operation to be
performed. The AD1200 board is designed so that it will only
generate DMA requests when the DMA enable bit, bit 3, in the
control status register, is set. When the DMA enable bit is clear,
0 the DMA request line is tristated off, the AD1200 card cannot
perform DMA i/o and does not drive the DMA channel lines at
all. This allows for DMA line sharing.

The position of the DMA channel jumper MUST match the
DMA channel used in the software. The range of instructions
controlling the enabling and use of the DMA facility are
described in later chapters.

Setting The DMA Channel Jumper Block.____________________________________

AD1200 Only

Only the AD1200 card can perform DMA driven i/o. Two
movable jumpers on the DMA jumper block, DMAJMP, are
used to select the channel through which the direct memory
access transfers pass.

Most user will not require DMA and so should leave the
DMA jumpers in the factory set position, DMA 1.

One of the jumpers is across the DMA request line and the
other across the DMA acknowledge line. Moving the jumper
pins select which DMA channel is invoked by the AD1200
board hardware. The jumpers can be in one of three positions,
see Figure 2-9. The jumpers must be set in pairs, both jumpers
MUST be set in the same DMA channel pair.
NOTE: Do not add an extra jumpers of your own across the
jumper block, it will only cause great confusion.

Page 36 Chapter 2

Installation Guide AD1200 Reference

Figure 2-9. The DMA Jumper Block.________________________________

DMA CHANNEL SELECTION. AD1200 Only.______________________ ____________

ЪДДДДДД¿
³ЫЫюююю³

DMA CHANNEL 1. THE DEFAULT

АДДДДДДЩ
ЪДДДДДД¿
³ююЫЫюю³

DMA CHANNEL 2.

АДДДДДДЩ
ЪДДДДДД¿
³ююююЫЫ³

DMA CHANNEL 3.

АДДДДДДЩ

Select the DMA channel line required by placing the pair
of jumpers across the appropriate pins. If in doubt leave in the
jumpers in the factory set condition, DMA 1.

D/A Output Range Selection._________________________

Both DAC0 and DAC1 may be independently set for a
variety of output voltage ranges. Five jumpers for each DAC are
used to configure the output range. The DAC1 jumpers are
labelled DAC1 and are found at the extreme top left hand side
of the AD1200 card. The DAC0 jumpers are labelled DAC0 and
are found at the top left hand side of the Ad1200 card, between
the DAC1 and ADC converter jumpers. One pair of jumpers
labelled BP and UNI determine whether the output range is
bipolar or unipolar, the other 3 jumpers labelled ABC determine
the voltage span.
Remember: Calibration should be performed when output ranges
are changed, to ensure the AD1200 remains in specification and
measurements are traceable back to recognised standards.

Chapter 2 Page 37

AD1200 Reference Installation Guide

Figure 2-10. D/A Output Range Selection.____________________________________

DAC OUTPUT RANGE._________________
BUCBA
PN

I

ЪДДДДД¿
³юЫюЫЫ³

0 to +10 Volts UNIPOLAR

АДДДДДЩ
ЪДДДДД¿
³юЫЫюЫ³

0 to +5 Volts UNIPOLAR

АДДДДДЩ
ЪДДДДД¿
³ЫююЫю³

-10 to +10 Volts BIPOLAR

АДДДДДЩ
ЪДДДДД¿
³ЫююЫЫ³

-5 to +5 Volts BIPOLAR DEFAULT

АДДДДДЩ
ЪДДДДД¿
³ЫюЫюЫ³

-2.5 to +2.5 Volts BIPOLAR

АДДДДДЩ

A/D Configuration._________________

The gain of the AD converter, the input channel type and
the input voltage range can all be independently selected.
The A/D input channel number selection is under software
control. On the AD1200 and AD1210/11 the gain is also under
software control. On the AD1220/21 the gain cannot be set by
software but is selected using the ADC GAIN jumpers.

Input Channel Type.

The AD1200 card may be set for 16 channels of single ended
input, for 8 channels of differential input or for 16 channels of
pseudo differential input. The 6 A/D input select jumpers are in
centre right of the card.

Page 38 Chapter 2

Installation Guide AD1200 Reference

Figure 2-11. A/D Channel Input Select.__________________________________

ADC CHANNEL INPUT SELECT._________________________

ЪДДДДДД¿
³ЫюююЫю³

8 Channel Differential Inputs

АДДДДДДЩ
ЪДДДДДД¿
³юЫюЫюЫ³

16 Pseudo Channel Differential Inputs

АДДДДДДЩ
ЪДДДДДД¿
³юЫЫююЫ³

16 Channel Single Ended Inputs DEFAULT

АДДДДДДЩ

Input Voltage Range.

The 4 input voltage range selection jumpers are in the centre top
of the AD1200 card, two select input span, two select uni or
bipolar ranges. Figures 2-14 and 2-15 give the options available.

Chapter 2 Page 39

AD1200 Reference Installation Guide

Figure 2-12. AD1200 A/D Input Range Selection.__________________________________________

AD1200 card - software selectable gain.

1 BU
05PN AD 20Vin ADC INPUT RANGE.________ ________________
VV I

ЪДДДД¿ ÚÄ¿
³þÛþÛ³ ³Ü³

0 to +10 Volts UNIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛþÛ³ ³ß³

0 to +5 Volts UNIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³ÛþÛþ³ ³Ü³

-10 to +10 Volts BIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³ÛþÛþ³ ³ß³

-5 to +5 Volts BIPOLAR DEFAULT

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛÛþ³ ³Ü³

-5 to +5 Volts BIPOLAR DUPLICATE

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛÛþ³ ³ß³

-2.5 to +2.5 V BIPOLAR

АДДДДЩ ÀÄÙ

Note: at each of the jumper selectable input ranges, the software
selectable gains of 1-2-4-8 or 1-10-100-1000 may be applied.
Thus on the AD1200PGL card when jumper set for -2.5 to +2.5
bipolar input, software selectable input ranges are:
gain =1 -2.5 to +2.5 volts
gain =2 -1.25 to +1.25 volts
gain =4 -0.625 to +0.625 volts
gain =8 -0.3125 to +0.3125 volts

Page 40 Chapter 2

Installation Guide AD1200 Reference

Figure 2-13. AD1210 A/D Input Range Selection.__________________________________________

AD1210 & AD1211 - software selectable gain.

1 BU
05PN AD 20Vin ADC INPUT RANGE.________ ________________
VV I

ЪДДДД¿ ÚÄ¿
³þÛþÛ³ ³Ü³

0 to +10 Volts UNIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛþÛ³ ³ß³

0 to +5 Volts UNIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³ÛþÛþ³ ³Ü³

-10 to +10 Volts BIPOLAR

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³ÛþÛþ³ ³ß³

-5 to +5 Volts BIPOLAR DEFAULT

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛÛþ³ ³Ü³

-5 to +5 Volts BIPOLAR DUPLICATE

АДДДДЩ ÀÄÙ
ЪДДДД¿ ÚÄ¿
³þÛÛþ³ ³ß³

-2.5 to +2.5 V BIPOLAR

АДДДДЩ ÀÄÙ

Note: at each of the jumper selectable input ranges, the software
selectable gains of 1-2-4-8 or 1-10-100-1000 may be applied.
Thus on the AD1211PGL card when jumper set for -2.5 to +2.5
bipolar input, software selectable input ranges are:
gain =1 -2.5 to +2.5 volts
gain =2 -1.25 to +1.25 volts
gain =4 -0.625 to +0.625 volts
gain =8 -0.3125 to +0.3125 volts

Chapter 2 Page 41

AD1200 Reference Installation Guide

Figure 2-14. AD1220 A/D Input Range Selection.__________________________________________

AD1220 and AD1221 cards only.

1 BU
05PN ADC GAIN ADC INPUT RANGE.________ ________________
VV I

ЪДДДД¿ ÚÄÄ¿
³þÛþÛ³ ³ÛÛ³

0 to +10 Volts UNIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³þÛþÛ³ ³þÛ³

0 to +5 Volts UNIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³þÛþÛ³ ³Ûþ³

0 to +2.5 Volts UNIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³þÛþÛ³ ³þþ³

0 to +1.25 Volts UNIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³ÛþÛþ³ ³ÛÛ³

-10 to +10 Volts BIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³ÛþÛþ³ ³þÛ³

-5 to +5 Volts BIPOLAR DEFAULT

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³ÛþÛþ³ ³Ûþ³

-2.5 to +2.5 V BIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³ÛþÛþ³ ³þþ³

-1.25 to +1.25 BIPOLAR

АДДДДЩ ÀÄÄÙ
ЪДДДД¿ ÚÄÄ¿
³þÛÛþ³ ³þþ³

-0.625 to +0.625 BIPOLAR

АДДДДЩ ÀÄÄÙ

Remember: Calibration should be performed whenever the input
ranges are changed, to ensure that the AD1200 remains in
specification, and that your analogue measurements are traceable
back to nationally and internationally recognised standards.

Page 42 Chapter 2

Installation Guide AD1200 Reference

8254 Counter Timer Pinouts._________________________

The AD1210, AD1211, AD1220 and AD1221 all have a
16 bit counter timer chip on board. This counter timer greatly
increases the functionality of the A/D cards.

The 8254 has consists of 3 16 bit counters, Counter 0,
Counter 1 and Counter 2. Each counter timer has a clock input,
a gate input and a counter output, these are TTL level signals.

Counter 1 has inputs CLK1, GATE1 and outputs OUT1.
Counter 2 has inputs CLK2, GATE2 and outputs OUT2.
The input to CLK1 is 600kHz from the pacer clock oscillator,
the output OUT1 drives the CLK2 input and the OUT2 output,
under program control, can be used as the A/D converted clock.
When bit 7 of the Timer Xmode register is zero the Pacer clock
output drives the A/D converter. When bit 7 of the Xmode
register is set then the CLK2 output drives the A/D converter.

Counter 0 has inputs CLK0, GATE0 and outputs OUT0. Counter
0 is unused and completely free for the user to program. Its
CLK0 input is shared by the bit 5 Digital Input Port line, pin 34
on the 50 way IDC connector. The GATE0 input is shared by
the bit 6 Digital Input Port line, pin 35 on the 50 way IDC
connector. Since both these lines are inputs they do not effect
the operation of the digital input port.
Counter 0’s OUT0 can be output via the bit 7 Digital Input Port
line, pin 36 on the 50 way IDC connector. A jumper on the A/D
card is used to connect OUT0 to Digital Input 7. Since this is an
output driving the line, Digital Input 7 can no longer be used.

Figure 2-15. OUT0 Via Digital Input Bit 7, Pin36.___________________________________________

AD1210/11 and AD1220/21 cards only.

ÚÄÄ¿
³Û

.

³

OUT0 NOT CONNECTED DEFAULT

ÀÄÄÙ
ÚÄÄ¿
³

Û³

OUT0 OUTPUT VIA DIGITAL INPUT 7, IDC PIN36

ÀÄÄÙ

Chapter 2 Page 43

AD1200 Reference Installation Guide

Installing The PC AD1200 Board In The Computer._____________________________________________

Note: Always turn the computer OFF before installing or

_____

removing any interface board..!!!

After having made sure that the i/o address is correctly set,
now is the time to insert the PC AD1200 board into the i/o
connector slots in the computer.

STEP 1 Before the PC AD1200 board can be installed the
power to the PC MUST be switched OFF!

Figure 2-16. Remove Cover Mounting Screws.________________________________________

STEP 2 Then using
a screw driver,
remove the cover
mounting screws on
the back panel of
the PC system unit.

Figure 2-17. Removing The PC Cover._________________________________

STEP 3 Next, remove the PC’s cover by sliding it forward and
up. It usually helps to disconnect the keyboard from the PC
since it tends to get in the way when the case is removed.

Page 44 Chapter 2

Installation Guide AD1200 Reference

Figure 2-18. Removing Blanking Cover.__________________________________

STEP 4 Choose an empty
expansion slot. The PC
AD1200 card will fit either a
full length or a short slot, a 8
bit PC type slot or a 16 bit
AT type slot. In general it is
wise to leave the larger slots
free for those boards that insist
on greater room. Remove the
blanking cover protecting the
slot on the PC back panel.
KEEP the blanking cover
screw safely for later.

Figure 2-19. Inserting The PC AD1200 Card._______________________________________

STEP 5 Now insert the PC
AD1200 card in the slot. Be
careful to ensure that the gold
plated pcb fingers fits neatly
into the i/o expansion
connector. Press down firmly
but evenly on the top of the
PC AD1200 card.

STEP 6 The 50 way IDC
connector should fit neatly
through the slot’s aperture to
the outside world.

Use the screw kept back from the blanking cover to screw the
PC AD1200 retaining bracket into the PC back panel housing.

Chapter 2 Page 45

AD1200 Reference Installation Guide

STEP 7 Now replace the system units cover by carefully sliding
it down and back over the system unit. Replace the cover
mounting screws.
STEP 8 After attaching all the monitor and keyboard cables,
power up the PC. Do not forget the mains power cable!

The PC should power on in the normal way.

AD1200 Backplane Signals.________________________

Looking at the back of the PC with AD1200 installed.
Note 8254 Only On AD1210/11/20/21 NOT on AD1200.

Figure 2-20. AD1200 J2 Pin Outs._____________________________

Signal PIN

ЪДДДДД¿

PIN Signal

AD Ch 0 1

³

1 2

ý³

2 AD Ch 8 (Ch0 Return)

AD Ch 1 3

³

3 4

ý³

4 AD Ch 9 (Ch1 Return)

AD Ch 2 5

³

5 6

ý³

6 AD Ch 10 (Ch2 Retn)

AD Ch 3 7

³

7 8

ý³

8 AD Ch 11 (Ch3 Retn)

AD Ch 4 9

³

O O

ý³

10 AD Ch 12 (Ch4 Retn)

AD Ch 5 11

³

O O

ý³

12 AD Ch 13 (Ch5 Retn)

AD Ch 6 13

³

O O

ý³

14 AD Ch 14 (Ch6 Retn)

AD Ch 7 15

³

O O

ý³

16 AD Ch 15 (Ch7 Retn)

Analogue Gnd 17

³

O O

ý³

18 Amp Low

------------------------------------------------------------­+12Volts Out 19

³

O O

ý³

20 -12Volts Out

------------------------------------------------------------­Power Ground 21

³

O O

ý³

22 DAC0 Output

DAC0 Ground 23

³

O O

ý³

24 DAC1 Output

DAC1 Ground 25

³

O O

ý³

26 Digital Ground

-----------------------------------------------------------­Digital Gnd 27

³

O O

ý³

28 Dig Input 0

Dig Input 1 29

³

O O

ý³

30 Dig Input 2

Dig Input 3 31

³

O O

ý³

32 Dig Ground

Dig Input 4 33

³

O O

ý³

34 Dig In 5 / 8254 CLK0

8254 GATE0/ Dig In 6 35

³

O O

ý³

36 Dig In 7 / 8254 OUT0

Digital Gnd 37

³

O O

ý³

38 Dig Output 0

Dig Output 1 39

³

O O

ý³

40 Dig Output 2

Dig Output 3 41

³

O O

ý³

42 Dig Ground

Dig Output 4 43

³

O O

ý³

44 Dig Output 5

Dig Output 6 45

³

O O

ý³

46 Dig Output 7

Digital Gnd 47

³

O O

ý³

48 Dig Ground

-----------------------------------------------------------­External Trigger

³

49 50

³

50 External Clock Input

Input

АДДДДДЩ

Page 46 Chapter 2

Installation Guide AD1200 Reference

The PC AD1200 board connects to the real world devices
using a 50 way IDC ribbon cable or a 50 pin D connector cable,
available from your dealer or via the HELP line on Intro page 2.

The 50 way IDC connector is arranged as two parallel
rows of 25 pins on a 0.1 inch pitch, the pin outs are given
above.

Signal Types.____________

The AD1200 card signals may be grouped as follows.

i) Analogue Inputs.

AD CH0-CH15.

These are the 16 inputs to the A/D converter when in
Single Ended or Pseudo Differential Mode.

Analogue Ground.

The return line for CH0-15. The analogue inputs in
Single Ended Mode are measured relative to this
signal, AGND.

Amp Low.

The return line for CH0-15. The analogue inputs in
Pseudo Differential Mode are measured relative to
this signal.

AD CH0-CH7, & CH0-CH7 Return.

These are the 8 input with the relevant return to the
A/D converter when in using Differential Mode.

ii) Analogue Outputs.

DAC0 Output, DAC0 Ground.

The analogue output and return line for D/A
converter DAC0. DAC0 ground is internally
connected to analogue ground, AGND.

DAC1 Output, DAC1 Ground.

The analogue output and return line for D/A
converter DAC1. DAC1 ground is internally
connected to analogue ground, AGND.

iii) Power Outputs.

+12 Volts, -12 Volts and Power Ground.

Power supply lines and return to drive the users own
interfaces. The +/-12 are fuse protected on the

Chapter 2 Page 47

AD1200 Reference Installation Guide

AD1200 card. Maximum permissible output current is
20 milliamps. The Maximum output current is largely
determined by the capacity of the power supply
installed in the PC. Check its rating.
Power ground is internally connected to analogue
ground, AGND.

iv) Digital Lines.

Digital Output 0-7.

These are the 8 lines from the digital output port.
They are TTL compatible.

Digital Input 0-7.

These are the 8 lines to the digital input port. They
are TTL compatible.

Digital Ground.

The ground return for the digital input and digital
output lines. There are 7 digital grounds and any
external digital circuits connected to the digital input
or output lines should be earthed via these ground
lines.
The digital grounds are internally connected to
analogue ground, AGND.

v) External Clock & Trigger.

External Clock.

The External Clock input can be used instead of the
onboard 600kHz oscillator to clock the A/D, DAC0
and DAC1 converters and to initiate IRQs and DMA
transfers to the converters and the digital port lines.
The clock is TTL compatible and the frequency can
be in the range DC to 1MHz.

External Trigger.

The negative going edge of the External Trigger
input can be used to start a series of conversions or
data transfers to the various ports. The trigger is TTL
compatible.

Page 48 Chapter 2

Installation Guide AD1200 Reference

Wiring Guidelines._________________

The AD1200 system is designed to accurately measure low
voltage signals thus noisy input signals will tend to render the
advanced design features useless. In particular, the performance
of the Programmable Gain Amplifier feature, available on the
boards, can be greatly effected by noise if signals are incorrectly
connected. It is imperative that good wiring practice be used to
obtain optimum results from the AD1200 card.

Twisted Pair Cables.__________________

Twisted pair cables may reduce the noise on Differential

Inputs noticeably. The high and low inputs of each channel

are twisted together so that any noise identical effects each

of these inputs. Since the converter measures the

DIFFERENCE between these two inputs the noise, being

identical is subtracted out. This is called Common Mode

Noise Rejection and it also greatly reduces the effects of

ground potential differences in taking signals from various

parts in a system.

Obviously this scheme does not work and should not

be attempted on Single Ended Inputs.

The output from the D to A converters, DAC0 out
with DAC0 ground and DAC1 out with DAC1 ground, can
similarly benefit from twisted pair cables.

Shielded Cables._______________

All leads, Single Ended Analogue input, Differential
Analogue Input, Analogue output, Digital input and Digital
output, should be shielded. This is the guard shield.
Each differential input twisted pair should be separately
shielded with the shield tied to analogue ground, AGND,
only at the SOURCE end of the connection, and that the
shield be continuous, ie through screw terminal boards,
panels, connectors etc.
The shield of each signal, or pair of differential signals,
should also be insulated from each other since each is
carrying its own current!

Chapter 2 Page 49

AD1200 Reference Installation Guide

Single Ended inputs and outputs, having a common ground,
should be arranged to ensure that ground loops are
avoided. Also prevent significant voltages being induced in
ground return leads returning to the single point ground.
Differential outputs from DAC0 and DAC1, similarly
should be shielded tied to AGND at the PC card end.
Digital inputs and digital outputs should be shielded by the
DIGITAL ground.

The Analogue Ground MUST be kept separate from
the Digital Ground especially when connections are
made to external, user supplied, circuits.

Input Voltage. Overvoltage Warning!_____________ ____________________

The analogue input to the A to D converter MUST be kept
within 20% of the maximum otherwise it may be damaged
or go permanently out of specification. This is of particular
importance when the Programmable Gain Amplifier is
being used, a gain of 1000 when set for -2.5 to +2.5 Volts
input gives a full scale reading from +/-2.5 milli Volts and
a maximum input level of +/-3.00 milli Volts!

Beware it is all too easy to over load the analogue
input at high gain levels.!

Problems!_________

If the system fails to power up check the following.
i.) Ensure that the PC AD1200 card is installed correctly.
ii.) Ensure that other cards in the PC have not been upset.
iii.) Ensure that the power is connected & PC is switched ON!
iv.) Ensure that the PC AD1200 i/o address is set correctly,

default is 0218h.

If all these have been checked and the PC still does not
power up then there is probably a conflict of i/o address between
the PC AD1200 board and another board in the PC. Ask your
dealer to check this or contact the HELP line as given on Intro
page 2.

Page 50 Chapter 2

Register Map AD1200 Reference

CHAPTER 3

PC AD1200

REGISTER

MAP.

Introduction.____________

This chapter explains the AD1200 Register Map, it details
the programmable status and control registers on the card. Whilst
most users will use the bundled driver software and so find this
information be be unnecessary it is included to make this manual
as complete as possible, to cover every eventuality.

I/O Address Map.________________

The AD1200 series uses 8 bytes of i/o address space.
These registers control all of the AD1200 functions, the driver
software access these registers. If you are using the bundled
driver software do not access the registers directly, otherwise
confusion may arise.

Unless you have GOOD REASON, you do not need to
program the locations.

Figure 3-1. AD1200 Register Map.______________________________

ЪДДДДДДДДДДВДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

ADDRESS

³ý

DEFAULT

ý³ý

REGISTER

ээээээээээ

ýý³

³

OFFSET

ýýýý³ý

ADDRESS

ý³

эээээээээээээ

ýýý

READ

ýýý

WRITE

ýý³
ГДДДДДДДДДДЕДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³ý

0000ýR/W

ý³ý

0218ýHex³ A/D CONTROL STATUS REGISTER

ý

ADCSR ADCSR

ý³

³ý

0001ýR/W

ý³ý

0219ýHex³ A/D GAIN CONTROL REGISTER ADGCR

ý

ADGCR

³

³ý

0002ýR/W

ý³ý

021AýHex³ A/D, DAC0 LOW BYTE

ýýýý ý

DAC0LO ADCLO

ý³

³ý

0003ýR/W

ý³ý

021BýHex³ A/D, DAC0 HIGH BYTE

ýýýý ý

DAC0HI ADCHI

ý³

³ý

0004

ýýýWý³ý

021CýHex³ DAC1 LOW BYTE

ýýýý ý

DAC1LO

ý³

³ý

0005

ýýýWý³ý

021DýHex³ DAC1 HIGH BYTE

ýýýý ý

DAC1HI

ý³

³ý

0006ýR/W

ý³ý

021EýHex³ DIGITAL I/O PORT

ýý

ýDIGIN ýDIGOUT

ý³

³ý

0007ýR/W

ý³ý

021FýHex³ TIMER CONTROL, EXTENDED MODE TIMERXM TIMERXM

³
ГДДДДДДДДДДБДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³ý

Note: Registers Do Not Always Read Back What Has Been Written

ý³

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Chapter 3 Page 51

AD1200 Reference Register Map

Register Types.______________

The registers fall into two types:-

1) Control registers such as the ADCSR, ADGCR and the
TIMERXM register. The registers contain mainly read and
write bits. These registers determine the SOURCE of the
A/D converter input and the RATE at which data can be
read from, or written to, the other ports.

2) Data input output ports such as the AD LO & HI input
registers, the DAC0 LO & HI output ports, the DAC1 LO
& HI output ports, the DIGITAL output port and the
DIGITAL input port. These registers are EITHER read OR
write.
In fact, the INPUT registers for the A/D converter are at
the same addresses as the OUTPUT registers for the D/A
converter DAC0. This causes no problem in practice since
the A/D converter is an input only device and DAC0 is an
output only device.

Read Write Assignments.______________________

Not every register is a read and write register. The

DAC1LO register and the DAC1HI register are write only
registers. The Control Status Register is a mixture of read only
bits, write only bits and read & write bits. For example the A/D
Control Status Register has three read only bits giving the status
of the A/D converter, 1 write only bit to clear an A/D error and
4 read/write bits that determine how the A/D conversions are to
be performed.

The AD1200 register map has been chosen with the

following design considerations:­i) Efficient use of the PC’s limited i/o space.
ii) Compatibility with DT2811 card and its extensive software

support.

iii) Compatibility with Asyst, Labtech and other third party

data acquisition packages.

Page 52 Chapter 3

Register Map AD1200 Reference

Power Up Conditions.___________________

On power up all registers are set to zero.

The A/D Control Status Register._____________________________

The most important register in the AD1200 series of cards
is the control status register. It is the primary control register for
the AD Converter, it holds the A/D Busy and A/D Done bits
which indicate whether an A/D conversion is in progress or
finished, its A/D Error and Clear Error bits are used to detect
and service A/D overrun or triggering mistakes. The DMA and
Interrupt enable bits are used to decide whether the A/D Done
bit causes a DMA read or system interrupt. Finally its Mode bits
determine whether single shot or continuous A/D conversions are
performed and what initiates the repetitive conversions and at
what rate they occur.

Figure 3-2. A/D Control Status Register.___________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

ADCSR A/D Control Status Register.

ээээээээээээээээээ³
ГДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДДДВДДДДДД´
³

³ý

BITý7

ý³ý

BITý6

ý³ý

BITý5

ý³ý

BITý4

ý³ý

BITý3

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BITý2

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BITý1

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BITý0

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³

0218

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A/D

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A/D

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A/D

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CLEAR

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DMA

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INT

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MODE

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MODE

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Hex

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DONE

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ERROR

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BUSY

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ERROR

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ENABLE

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ENABLE³ BIT 1

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BIT 0

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R/W

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R/W

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АДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДЩ

Bit 7 A/D Done, Read Only.________________________

This bit is indicates that the A/D converter has a reading
ready.
Set By: The A/D converter when it has finished converting an

analogue input.
If Bit 3, DMA Enable, of the ADCSR is also set
then a DMA cycle will be generated when this bit is
set by the ADC.
If Bit 2, Interrupt Enable, of the ADCSR is also set,
but not Bit 3, then an interrupt will be generated
when this bit is set by the ADC.

Chapter 3 Page 53

AD1200 Reference Register Map

Reset By: Reading the ADC data high byte at Register 3.

This bit is automatically cleared at power up.

Bit 6 A/D Error, Read Only._________________________

This bit is indicates that an error has occurred during the
A/D conversion.
Set By: Overrun error. A new conversion has been completed

whilst the previous has not been read, ie ADCHI,
Register 3 has not been read.
Trigger error. A new conversion has been requested
while the current conversion is in progress.
If Bit 2, Interrupt Enable, of the ADCSR is also set,
then an interrupt will be generated when this bit is
set by the ADC.

Reset By: Writing a 1 to bit 4 of the ADCSR.

This bit is automatically cleared at power up.

Bit 5 A/D Busy, Read Only.________________________

This bit is indicates that an A/D conversion is in progress.
Set By: An A/D strobe. Any further A/D strobes while this

bit is set will cause an A/D error due to overrun.

Reset By: This bit is automatically cleared when the A/D

conversion is finished and the data is ready to be
read from the ADCLO and ADCHI registers.

Bit 4 Clear A/D Error, Write Only._______________________________

Writing a 1 to this bit clears the A/D Error bit, bit 6 of the
ADCSR.
Note: This bit ALWAYS reads back as 0.

Bit 3 DMA Enable, Read / Write. AD1200 Only_____________________________ ____________

This bit is used to enable DMA on the AD1200 card only.
This bit is always reads as 0 on the AD1210, AD1211, AD1220
and AD1221 cards since these do not have DMA capability.

The top of range AD1200 card can card perform DMA on
A/D Conversion Done and also generate DAC0 and DAC1 pacer

Page 54 Chapter 3

Register Map AD1200 Reference

clock DMA requests and TTL i/o port pacer DMA requests
when the Extended Mode bits are set in the Timer Control
Register. When the Extended Mode bits are set the Pacer clock
is used to initiate the DMA cycle, the data is read from the TTL
input port or written to the TTL output port or the DAC0 or
DAC1 registers.

When Set: DMA i/o is enabled and a DMA cycle with be

initiated due to A/D Done or Pacer Strobe depending
on the settings of the Mode Bit 1 and Mode bit 0
registers and the extended Mode bits of the Timer
Control register.

If Clear: No DMA operations take place when this line is

clear, the DMA lines are tristated and the DMA

channel is free for use by other devices.
Set By: This bit is set under program control.
Reset By: This is cleared under program control.

This bit is automatically cleared at power up.

Bit 2 Interrupt Enable, Read / Write.________________________________

This bit is is used to enable interrupts, IRQs.
The whole range of AD1200 cards can generate A/D Done, and
A/D Error interrupts.
The top of range AD1200 card can also generate DAC0 and
DAC1 pacer clock interrupts and TTL i/o port pacer interrupts
when the Extended Mode bits are set.

When Set: Interrupts are generated when A/D Done bit or the

A/D Error bits is set.
AD1200 only: IRQ i/o due to A/D Done or Pacer
Strobes depending on combination of Mode Bits 0 &
1 and the Extended Mode bits in the Timer register.

If Clear: No Interrupts are generated this bit is clear, the IRQ

lines are tristated and the IRQ channel is free for use

by other devices.
Set By: This bit is set under program control.
Reset By: This is cleared under program control.

Chapter 3 Page 55

AD1200 Reference Register Map

This bit is automatically cleared at power up.

Bits 0 & 1. Mode Bit 0 & 1. Read / Write.____________________________________

These bit are used to control the four modes of the A/D

converter and function according to the following table.

Figure 3-3. Mode 0 & 1 Bits._________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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ADCSR A/D Control Status Register.

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³

MODE

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FUNCTION

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³

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Single A/D Conversion when ADGCR

³
³

³ ³ ³ A/D Gain/Channel Register, is written.

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³

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Continuous A/D conversions by pacer clock

³
³

³ ³ ³ using on board 600kHz oscillator.

³
³

³ ³ ³ Clock started when ADGCR is written.

³
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³

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Continuous A/D conversions by pacer clock

³
³

³ ³ ³ using on board 600kHz oscillator.

³
³

³ ³ ³ Clock started by Ext Trigger -ve edge.

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Continuous A/D conversions by pacer clock

³
³

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³

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³
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The AD1210-21 cards, with the 8254 counter timer chip on
board, uses the TIMER register bits 7 as a method of selecting
the 8254 counter timer INSTEAD on the on board 600kHz pacer
clock as the source of the A/D converter strobe pulses. Bit 6 has
no function and reads back as 0.

The AD1200 card has extra modes that are selected by the
TIMER register bits 6 & 7 in conjunction with ADCSR Mode
bit 0 & 1. In this scheme the TIMER Extended Mode bits are
used to determine on which port, ADC, DAC0, DAC1 or Digital
i/o, the continuous conversions take place. When both Extended
Mode bits are 0, the AD1200 card performs as all the other
cards in the series and the repetitive conversions take place on

Page 56 Chapter 3

Register Map AD1200 Reference

the A/D converter.

Figure 3-4. AD1200 Extended Mode Bits.____________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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AD1200 Card Only TIMER Extended Mode Bits

ý³
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BITý6

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Continuous Conversion Performed On

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³

0

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A/D Converter Compatible Mode

³
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³

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DAC0

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³

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DAC1

³
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³

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1

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DIGITAL I/O PORT

³
АДДДДДДДБДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Figure 3-5. AD1210-21 Extended Mode Bit._____________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

AD1210-AD1221 TIMER Extended Mode Bits

эээээ

ý ý ý ý ý

ý³
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³

BITý7

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AD Clock

³
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³

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Always= 0

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600kHz On Board Pacer Clock

³
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³

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8254 Timer Counter

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АДДДДДДДБДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Initialising The A/D Converter.___________________________

The A/D converter should be initialised by performing the
following steps before changing the mode set in the ADCSR.
The Real World driver software supplied with the card performs
this automatically on mode changes, or when the ’Init’ routine is
called.
i) Write 00hex to the ADCSR, ie disable pacer clock

conversions, stop pacer clock running, disable interrupts,

disable DMA.
ii) Wait at least 100uS, ie allow any A/D conversion in

progress to finish.
iii) Read the high byte of the A/D data, ADCHI, ie clear the

A/D Done bit.
iv) Write 10hex to the ADCSR, ie clear any A/D Error bit.

Chapter 3 Page 57

AD1200 Reference Register Map

The A/D Gain Channel Register.____________________________

The A/D Gain Channel Register, ADGCR, is used to select
the input channel to the A/D converter and the gain applied to
the input signal by the programmable gain amplifier.
Note: The AD1221 and AD1220 cards do NOT have

programmable gain and ADGCR bits 6 & 7 always read

back as zero.
When in Mode 0, single conversion mode, then writing to the
A/D Gain Channel Register forces the A/D Converter to start its
next conversion. A short delay, 4uS, between writing the
ADGCR and the start of conversion signal is automatically
inserted by the AD12XX card to allow the channel select
circuitry and the Programmable Gain Amplifier output to
stabilise. This delay is not inserted in continuous A/D conversion
modes since the new channel information is written after the
sample and hold circuitry acquires the input voltage due to the
pacer clock strobe signal.

Figure 3-6. A/D Gain Channel Register.__________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

ADGCR A/D Gain Channel Register.

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³

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0219³ Gain

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Channel³Channel³Channel³Channel

³
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³ýýýý³

AD1221 & AD1220

³ээээээээээээээээээээээээээээээээээээээээээээээ³

³ýýýý³ýý

DOýNOTýHAVE

ээ³ээээээээээээээээээээээээээээээээээээээээээээээ³

³ýýýý³ýý

PROGRAMMABLE

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³ýýýý³

GAIN READ AS 0

э³ээээээээээээээээээээээээээээээээээээээээээээээ³

АДДДДБДДДДДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Bits 6 & 7. Gain select. Read / Write.________________________________

These two bits select the gain that the Programmable Gain
Amplifier applies to the input voltage. Thus the voltage applied
to the cards edge connector is multiplied by this gain value

Page 58 Chapter 3

Register Map AD1200 Reference

before it is fed to the A/D converter. The L suffix cards can
take LOW input signals, 2.5 milli Volts full scale, and boost
them by a factor of up to 1000, ie 2.5 Volts full scale. Please
ensure that the boosted input voltage does not exceed the
jumper selected input range. L suffix cards, eg AD1211L have
gains of 1-10-100-1000. H suffix cards, eg AD1211H have gains
of 1-2-4-8.

Set By: These bits are set under program control.
Reset By: They are cleared under program control.

These bits are automatically cleared at power up.

Note: The AD1221 and AD1220 cards do NOT have

programmable gain and ADGCR bits 6 & 7 always
read back as zero.

Figure 3-7. Gain Selection._______________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

ADGCR A/D Gain Selection.

ý³
ГДДДДДДДДДВДДДДДДДДДВДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДД´
³

Gain ³ Gain ³ ³ Gain Selected

³

³

Select1 ³ Select0 ³ ³

³
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Bit 7 ³ Bit 6

³ý

Hex

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AD12XXL

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AD12XXH

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АДДДДДДДДДБДДДДДДДДДБДДДДДБДДДДДДДДДДДДБДДДДДДДДДДДДЩ

Bits 4 & 5. Reserved For Future Expansion. Read / Write.__________________________________________________

These two bits currently have no effect, and are thus

"don’t care" bits. They should be written to as 0 to ensure
compatibility with future enhancements to the AD1200 range.

Bits 0, 1, 2 & 3. Channel Select. Read / Write._______________________________________

These four bits select the channel that is fed to the input of

Chapter 3 Page 59

AD1200 Reference Register Map

the A/D converter. For Single Ended or Pseudo Differential
operation all 4 bits are used to select one of the 16 possible
channels. For Differential operation only bits 0, 1 & 2 effect the
channel selection, bit 3 is a "don’t care" bit.

Set By: These bits are set under program control.
Reset By: They are cleared under program control.

These bits are automatically cleared at power up.

Figure 3-8. Channel Selection.__________________________

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ADGCR A/D Channel Selection.

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³

Channel Select

³

Channel Selected

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Hex ³Single Ended

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Differential

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АДДДДДДДДДДДДДДДДДБДДДДДБДДДДДДДДДДДДБДДДДДДДДДДДДДДЩ

The A/D Converter Input Registers. Read Only_________________________________________

The A/D Converter returns a 12 bit value that is the digital

representation of the selected analogue input signal. This 12 bit
value is read as from two adjacent 8 bit, read only, registers.
The ADCLO register contains the lower 8 bits of the 12 bit
value. The ADCHI register contains the upper 4 bits of the 12
bit value. The upper most 4 bits from the ADCHI register
always read back as 0.

Page 60 Chapter 3

Register Map AD1200 Reference

Reading the ADCHI register resets the A/D Done bit and so the
A/D converter can be retriggered to start performing its next
conversion. Reading the ADCLO register does not effect the
A/D Done bit. Since reading ADCHI clears A/D Done and
another reading may be triggered it is best to read ADCLO first
and then read ADCHI.
The ADCHI and ADCLO registers are READ ONLY, data
written to them actually goes to the D/A converter, DAC0 which
occupies the same i/o address space, and will eventually appear
as an analogue output voltage from this converter.

The 12 bit ADC converter value is obtained from:-

ADCDATA= ADCHI*256 + ADCLO.
The ADC data is in the form of right justified offset binary, ie
the lowest voltage gives a value of 000hex whilst the highest
voltage gives a value of FFFhex.
For Unipolar signals, ie 0 to +FULL_SCALE_VOLTS, the actual
ADC voltage is obtained from:­ADCVOLT= (ADCDATA * FULL_SCALE_VOLTS ) /4096
For Bipolar signals, ie -FULL_SCALE_VOLTS to
+FULL_SCALE_VOLTS, the actual ADC voltage is obtained
from:­ADCVOLT= (ADCDATA-2048) *FULL_SCALE_VOLTS /2048

Figure 3-9. ADC Low Byte Input Register._____________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

ADCLO Input Register.

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Chapter 3 Page 61

AD1200 Reference Register Map

Figure 3-10. ADC High Byte Input Register.______________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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ADCHI Input Register.

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The DAC0 D/A Converter Output Registers.______________________________________

Write Only__________

The DAC0 D/A Converter takes a 12 bit value that is the
digital representation of the required analogue output voltage.
This 12 bit value is written to two adjacent 8 bit, write only,
registers. The lower 8 bits of the 12 bit value are written to the
DAC0LO register. The upper 4 bits of the 12 bit value are
written to lower most 4 bits of the DAC0HI register. The upper
most 4 bits written to the DAC0HI register are "don’t care" bits
but should always be set to 0 for compatibility with 16 bit D/A
software and data formats.

The DAC0HI and DAC0LO registers are WRITE ONLY, data
cannot be read back from them, instead a read of these registers
returns the latest output from the A/D converter, which occupies
the same i/o address space. Since reading ADCHI clears the A/D
Done bit in the ADCSR, attempts to "read back" the DAC0
output may cause strange errors to occur, resulting in A/D data
being lost.

The DAC data is in the form of right justified offset binary, ie a
value of 000hex gives the lowest output voltage whilst a value
of FFFhex gives the highest output voltage.

The value to write to the 12 bit D/A converter to obtain any
particular output voltage, DACVOLT, is obtained by:-

DAC0HI = DAC0DATA / 256

DAC0LO = DAC0DATA MOD 256 remainder function

Page 62 Chapter 3

Register Map AD1200 Reference

For Unipolar signals, ie 0 to +FULL_SCALE_VOLTS, the actual
12 bit DAC0DATA value is obtained from:­DAC0DATA= (DACVOLT *4096 ) /FULL_SCALE_VOLTS

For Bipolar signals, ie -FULL_SCALE_VOLTS to
+FULL_SCALE_VOLTS, the actual 12 bit DAC0DATA value is
obtained from:-

DAC0DATA=

( DACVOLT*2048 / FULL_SCALE_VOLTAGE ) + 2048

Figure 3-11. DAC0 Low Byte Output Register.________________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DAC0LO Output Register.

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021A

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Figure 3-12. DAC0 High Byte Output Register._________________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DAC0HI Output Register.

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АДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДДБДДДДДДЩ

The DAC1 D/A Converter Output Registers.______________________________________

Write Only__________

The DAC1 D/A Converter takes a 12 bit value that is the
digital representation of the required analogue output voltage.
This 12 bit value is written to two adjacent 8 bit, write only,
registers. The lower 8 bits of the 12 bit value are written to the
DAC0LO register. The upper 4 bits of the 12 bit value are
written to lower most 4 bits of the DAC1HI register. The upper

Chapter 3 Page 63

AD1200 Reference Register Map

most 4 bits written to the DAC1HI register are "don’t care" bits
but should always be set to 0 for compatibility with 16 bit D/A
software and data formats.

The DAC1HI and DAC1LO registers are WRITE ONLY, data
cannot be read back from them, instead a read of these registers
returns garbage since there is no corresponding read registers at
these addresses.

The DAC data is in the form of right justified offset binary, ie a
value of 000hex gives the lowest output voltage whilst a value
of FFFhex gives the highest output voltage.

The value to write to the 12 bit D/A converter to obtain any
particular output voltage, DACVOLT, is obtained by:-

DAC1HI= DAC1DATA / 256
DAC1LO= DAC1DATA MOD 256 remainder function

For Unipolar signals, ie 0 to +FULL_SCALE_VOLTS, the actual
12 bit DAC1DATA value is obtained from:­DAC1DATA= (DACVOLT *4096 ) /FULL_SCALE_VOLTS

For Bipolar signals, ie -FULL_SCALE_VOLTS to
+FULL_SCALE_VOLTS, the actual 12 bit DAC1DATA value is
obtained from:-

DAC1DATA=

( DACVOLT*2048 / FULL_SCALE_VOLTAGE ) + 2048

Page 64 Chapter 3

Register Map AD1200 Reference

Figure 3-13. DAC1 Low Byte Output Register.________________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DAC1LO Output Register.

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Figure 3-14. DAC1 High Byte Output Register._________________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DAC1HI Output Register.

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The Digital Output Port Register. Write Only_____________________________ __________

The Digital Output Port Register, DIGOUT, is an 8 bit
write only register. The bit values written correspond exactly
with the on/off logic state of the 8 TTL output lines. Thus bits
set true force the corresponding DIGOUT line high, those bits
set false force the DIGOUT line low.

Figure 3-15. DIGOUT Output Register.__________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DIGOUT Digital Output Port Register.

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Writing 0FFhex to the DIGOUT register forces all lines
high, writing 00hex forces lines low. Writing 01hex forces only
DIGOUT bit 0 high, all the rest are low.
TTL output logic level low is 0.0 ~0.8 Volts.

Chapter 3 Page 65

AD1200 Reference Register Map

TTL output logic level high is 2.4 ~5.0 Volts.

The Digital Input Port Register. Read Only____________________________ __________

The Digital Input Port Register, DIGIN, is an 8 bit read
only register. The bit values read represent the logic levels
present on the 8 TTL input lines. Thus lines that are high cause
the corresponding DIGIN bit to read high, those lines that are
low cause the corresponding DIGIN bit to read low. If on
reading the DIGIN register a value of 0FFhex is obtained then
all the TTL input lines where true. A reading of 00hex means
that all lines were low. A reading of 01hex means that only
DIGIN line 0 was high, all the rest are low.
TTL output logic level low is 0.0 ~0.8 Volts.
TTL output logic level high is 2.4 ~5.0 Volts.

Figure 3-16. DIGIN Output Register.________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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DIGIN Digital Input Port Register.

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021E³ DIGIN ³ DIGIN ³ DIGIN ³ DIGIN ³ DIGIN ³ DIGIN ³ DIGIN ³ DIGIN

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The Timer & Extended Mode Register. Read/ Write__________________________________ ___________

The TIMEREX Register, is an 8 bit read/write register. It
is used to select the pacer clock frequency and to select
Extended Mode operation on the AD1200 card.

Page 66 Chapter 3

Register Map AD1200 Reference

Figure 3-17. TIMEREX Register._____________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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TIMEREX Timer Counter Extended Mode Register.

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021F³ XMODE ³ XMODE ³ TIMER ³ TIMER ³ TIMER ³ TIMER ³ TIMER ³ TIMER

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Bits 0-5, TIMER Pacer Clock Divisor Bits. Read/Write._____________________________________ ___________

The lower 6 bits of the TIMEREX register, TIMER 0-5,
are used to select the pacer clock frequency. The bit pattern
written selects the divisor factor applied to the fundamental
frequency, as given in the following table. The source of the
fundamental clock frequency is either the on board 600kHz
oscillator or a user supplied external clock and is chosen by the
MODE 0 & 1 bits in the ADCSR register.
When strobing the A/D converter do not choose pacer clock
frequencies above the maximum throughput of the converter.
eg 30kHz for AD1211 and AD1221
eg 100kHz for AD1200/01, AD1210 and AD1210

Do not exceed the throughputs of the D/A converters, DAC0 and
DAC1, or the Digital i/o port when using pacer clock strobes in
the AD1200 cards Extended Modes.
eg 100kHz for AD1200 D/A converters DAC0 or DAC1
eg 1MHz for AD1200 Digital Input or Output ports

Chapter 3 Page 67

AD1200 Reference Register Map

Figure 3-18. Pacer Clock Divisor____________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
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TIMEREX Bits 0-5 Pacer Clock Frequency Selection.

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ý ý³
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0 1 ý1 1 1 0

ýý³

1E

ý³

3000000

³ý

0.2

ý ý³
³ýý

0 1 ý1 1 1 1

ýý³

1F

ý³

30000000

³ý

0.02

ý ý³
АДДДДДДДДДДДДДДДДДДДДДДДДДБДДДДДБДДДДДДДДДДДБДДДДДДДДДДДДДДДЩ

p.t.o.

Page 68 Chapter 3

Register Map AD1200 Reference

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

TIMEREX Bits 0-5 Pacer Clock Frequency Selection.

ý³
ГДДДДДДДДДДДДДДДДДДДДДДДДДВДДДДДВДДДДДДДДДДДВДДДДДДДДДДДДДДД´
³

TIMER Bit Pattern

ý³

Hex ³ Base

³

Frequency Of

³

ГДДДДДДДДДДДДДДДДДДДДДДДДД´

³ Frequency

³

On Board

³

³ý

5 4 3 2 1 0

³

Value³ Divisor

³

Oscillator Hz

³
ГДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДД´
³ýý

1 0 ý0 0 0 0

ýý³

20

ý³ ý

ý4

³ý

150k

ý ý³

³ýý

1 0 ý0 0 0 1

ýý³

21

ý³ ý

40

³ý

15k

ý ý³

³ýý

1 0 ý0 0 1 0

ýý³

22

ý³ ý

400

³ý

1500

ý ý³

³ýý

1 0 ý0 0 1 1

ýý³

23

ý³ ý

4000

³ý

150

ýý³

³

ý1 0 ý0 1 0 0

ýý³

24

ý³ ý

40000

³ý

15

ýý³

³ýý

1 0 ý0 1 0 1

ýý³

25

ý³ ý

400000

³ý

1.5

ýý³

³ýý

1 0 ý0 1 1 0

ýý³

26

ý³ ý

4000000

³ý

0.15

ýý³

³ýý

1 0 ý0 1 1 1

ýý³

27

ý³

40000000

³ý

0.015

ýý³

³ýý

1 0 ý1 0 0 0

ýý³

28

ý³ ý

5

³ý

120k

ý ý³

³ýý

1 0 ý1 0 0 1

ýý³

29

ý³ ý

50

³ý

12k

ý ý³

³ýý

1 0 ý1 0 1 0

ýý³

2A

ý³ ý

500

³ý

1200

ý ý³

³ýý

1 0 ý1 0 1 1

ýý³

2B

ý³ ý

5000

³ý

120

ý ý³

³ýý

1 0 ý1 1 0 0

ýý³

2C

ý³ ý

50000

³ý

12

ý ý³

³ýý

1 0 1 1 0 1

ýý³

2D

ý³

ý500000

³ý

1.2

ý ý³

³ýý

1 0 ý1 1 1 0

ýý³

2E

ý³

5000000

³ý

0.12

ý ý³

³ýý

1 0 ý1 1 1 1

ýý³

2F

ý³

50000000

³ý

0.012

ý ý³
ГДДДДДДДДДДДДДДДДДДДДДДДДДЕДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДД´
³ýý

1 1 ý0 0 0 0

ýý³

30

ý³ ý

ý6

³ý

100k

ý ý³
³ýý

1 1 ý0 0 0 1

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31

ý³ ý

60

³ý

10k

ý ý³
³ýý

1 1 ý0 0 1 0

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32

ý³ ý

600

³ý

1k

ý ý³
³ýý

1 1 ý0 0 1 1

ýý³

33

ý³ ý

6000

³ý

100

ýý³

³

ý1 1 ý0 1 0 0

ýý³

34

ý³ ý

60000

³ý

10

ýý³

³ýý

1 1 ý0 1 0 1

ýý³

35

ý³ ý

600000

³ý

1

ýý³

³ýý

1 1 ý0 1 1 0

ýý³

36

ý³ ý

6000000

³ý

0.1

ýý³

³ýý

1 1 ý0 1 1 1

ýý³

37

ý³

60000000

³ý

0.01

ýý³

³ýý

1 1 ý1 0 0 0

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38

ý³ ý

12

³ý

50k

ý ý³
³ýý

1 1 ý1 0 0 1

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39

ý³ ý

120

³ý

5k

ý ý³
³ýý

1 1 ý1 0 1 0

ýý³

3A

ý³ ý

1200

³ý

500

ý ý³
³ýý

1 1 ý1 0 1 1

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3B

ý³ ý

12000

³ý

50

ý ý³
³ýý

1 1 ý1 1 0 0

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3C

ý³ ý

120000

³ý

5

ý ý³
³ýý

1 1 1 1 0 1

ýý³

3D

ý³ ý

1200000

³ý

0.5

ý ý³
³ýý

1 1 ý1 1 1 0

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3E

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0.05

ý ý³
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1 1 ý1 1 1 1

ýý³

3F

ý³

120000000

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0.005

ý ý³
³ýýýý

ý

ý³

ýý³

ýý

ý³

ý³

АДДДДДДДДДДДДДДДДДДДДДДДДДБДДДДДБДДДДДДДДДДДБДДДДДДДДДДДДДДДЩ

Bits 6 & 7 XMODE, Extended Mode Read/Write.________________________________ ___________

For AD1200 card only the top 2 bits of the TIMEREX
register, XMODE 6 & 7, in conjunction with MODE 0 & 1 bits
in the ADCSR, determine which port is paced by the clock.

Chapter 3 Page 69

AD1200 Reference Register Map

The AD1210-21 cards, with the 8254 counter timer chip on
board, uses the TIMER register bits 7 as a method of selecting
the 8254 counter timer INSTEAD on the on board 600kHz pacer
clock as the source of the A/D converter strobe pulses. Bit 6 has
no function and reads back as 0.

Figure 3-19. AD1200 Extended Mode Bits._____________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

AD1200 Card Only TIMER Extended Mode Bits

ý³
ГДДДДДДДВДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

BITý7

ý³ý

BITý6

ý³

Continuous Conversion Performed On

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

0

ýý³ý

0

ýý³

A/D Converter Compatible Mode

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

0

ýý³ý

1

ýý³

DAC0

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

1

ýý³ý

0

ýý³

DAC1

³
ГДДДДДДДЕДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

1

ýý³ý

1

ýý³

DIGITAL I/O PORT

³
АДДДДДДДБДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Figure 3-20. AD1210-21 Extended Mode Bit.______________________________________

ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³эээээ

AD1210-AD1221 TIMER Extended Mode Bits

эээээ

ý ý ý ý ý

ý³
ГДДДДДДДВДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

BITý7

ý³ý

BITý6

эээээ³

A/D Clock Source

³
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³

0

ýý³

Always= 0

ý³

600kHz On Board Pacer Clock

³
ГДДДДДДДЕДДДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³

1

ýý³ý

Always= 0

ý³

8254 Timer Counter

³
АДДДДДДДБДДДДДДДДДДДБДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

The 8254 Counter Timer Registers. Read/ Write_______________________________ ___________

The AD1210-21 cards have an 8254 counter timer chip on
board, the base address of the 8254 is 8 byte before 8 registers
of the AD card. Thus for an AD1210 card with a base address
of 0218hex the 8254 counter timer is at 0210hex. The counter
timer occupies only four location, 0210-0213 hex, a shadow or
copy of these registers appears at 0214-0217 hex also. This
shadow copy of the registers does NOT mean that two counter
timers are present on the card.

Page 70 Chapter 3

Register Map AD1200 Reference

Figure 3-21. 8254 Counter Timer Register Map._________________________________________

ЪДДДДДДДДДДВДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

ADDRESS

³ý

DEFAULT

ý³ý

REGISTER

ээээээээээ

ýý³

³

OFFSET

ýýýý³ý

ADDRESS

ý³

эээээээээээ

ээээээээээ

ýý³
ГДДДДДДДДДДЕДДДДДДДДДЕДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´
³ý

0000ýR/W

ý³ý

0210ýHex³ COUNTER 0 REGISTER

ý

ý³

³ý

0001ýR/W

ý³ý

0211ýHex³ COUNTER 1 REGISTER

³

³ý

0002ýR/W

ý³ý

0212ýHex³ COUNTER 2 REGISTER

ý³

³ý

0003 ýW

ý³ý

0213ýHex³ CONTROL WORD REGISTER WRITE ONLY

ý³

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

Counter 0 is not used on the A/D board. Its i/o pins are shared with
the digital input port pins 34, 35, 36. Counter 0, counts pulses on
the CLK 0 input, pin 24, when the GATE 0 pins is high, pin 35. Its
output is via pin 36 of the 50 way IDC connector, provided the OUT VIA
PIN 36 jumper pin as been set.
A CLK pulse is defined as a rising edge, then a falling edge, in that
order of the CLK input. A trigger pulse is a rising edge on the GATE
input.
Counters 1 and 2 are dedicated to AD trigger functions, and provided
the XMODE bit 7 is set, can be used instead of the Pacer clock as the
source of strobes to start conversions on the A/D converter.

Chapter 3 Page 71

AD1200 Reference Calibration

CHAPTER 4

CALIBRATION.

Introduction.____________

This chapter describes how to perform a calibration of the
AD1200 analogue circuitry. The use of the calibration software,
the position and function of the onboard trimmer pots and use of
ancillary equipment are all described. Calibration should be
performed at regular intervals, at least twice a year, and
whenever the input or output ranges are changed, to ensure that
the AD1200 remains in specification, and that your analogue
measurements are traceable back to nationally and internationally
recognised standards.

All AD1200 cards are factory calibrated with Time
Electronics calibration equipment, the voltage source is a Time
2003N D.C. Voltage Calibrator, the voltmeter is A Time
Electronics 5075 Digital Multimeter. The best on the market.

Note Allow the PC with the AD1200 card, cables, the

voltmeter and/or the voltage source to warm up and

allow the operating environment temperature to

stabilise before attempting calibration. Provided the

room temperature is stable connect the calibration

equipment together, remove the PC cover and leave the

PC and card to warm up for at least one hour. Do not

expect a successful calibration in a system just turned

on, first thing in a cold office on a winters morning.

Calibrating The Digital To Analogue Output._______________________________________

There are two analogue outputs on the AD1200 card,
DAC0 and DAC1, each must be calibrated separately.

Page 72 Chapter 4

Calibration AD1200 Reference
Outline._______

The calibration is simple. It consists of only two steps.

i) Set the D/A converter to its LOWEST output, then using

an accurate voltmeter check the output voltage, adjust the
OFFSET trim potentiometer to get the desired value.

ii) Set the D/A converter to its HIGHEST output, then using

an accurate voltmeter check the output voltage, adjust the
GAIN trim potentiometer to get the desired value.

Provided the calibration is performed in the correct order,
OFFSET adjust then GAIN adjust, there should be no interaction
between the two adjustments.

Equipment Required.___________________

A digital voltmeter capable of a stable and clear resolution
of 1/10th of LSB at both ends of the range of the converter.
Thus the voltmeter should have a range of -10 to +10 volts and
a resolution of 1.22mV/10 = 122uV or better.

Figure 4-1. DAC Trimmer Pot Layout.__________________________________

ÚÄÄÄ

DAC1

ÄÄÄ¿ ÚÄÄÄ

DAC0

ÄÄÄ¿

UNIOFFSET UNIOFFSET

³

BPOFFSET

³

BPOFFSET

³³

GAIN

³³

GAIN

ææ

æææ

æ
ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³ÚÁ¿ ÚÁ¿ÚÁ¿ ÚÁ¿ ÚÁ¿ÚÁ¿

³ÚÄ

³³

³³

³³ ³³

³³

³³ ³

³³
³ÀÄÙ АДЩАДЩ ÀÄÙ АДЩАДЩ ÚÄij³Ä¿
³

POT9 POT7 POT6 POT4

³³³

³

POT8 POT5

³³³
³ ³³³
³

³³³
³

³³³
³ ³³³
³ ³³³
³

³³³
³

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АДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿ ÚÄÄÙ³

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ ³

Chapter 4 Page 73

AD1200 Reference Calibration

DAC0 Calibration Procedure.__________________________

i) Set up the DAC0 output jumpers for the output range

required, make a note of the output range.

ii) Using leads as short as possible connect up the digital

voltmeter as in Figure 4-2

iii) Set DAC0 to its LOWEST output value by writing the

digital code 000 hex to the converter.

iv) Using Figure 4-3 determine the ideal output voltage for the

000 hex input code, the 1/10 LSB value is the precision
required. This is the OFFSET adjustment.
For BIPOLAR ranges adjust trim pot 5 for minus full scale
value. eg for range -5 to +5 bipolar the ideal offset voltage
is -5.0000 Volts +/- 0.0002 Volt.
For UNIPOLAR ranges adjust trim pot 6 for zero volts.
eg for range 0 to +5 unipolar the ideal offset voltage is

0.0000 Volts +/- 0.0001 Volt.

v) Set DAC0 to its HIGHEST output value by writing the

digital code FFF hex to the converter.

vi) Using Figure 4-3 determine the ideal output voltage for the

FFF hex input code, the 1/10 LSB value is the precision
required. This is the GAIN adjustment.
Adjust trim pot 4 for maximum positive output voltage.
eg for range -5 to +5 bipolar the ideal full scale voltage is
+4.9987 Volts +/- 0.0002 Volt.
eg for range 0 to +5 unipolar the ideal full scale voltage is
+4.9987 Volts +/- 0.0001 Volt.

Page 74 Chapter 4

Calibration AD1200 Reference

Figure 4-2. DAC0 Calibration Wiring Diagram._________________________________________

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿ ЪДДДДДДДДДДДД¿

³ÚÄÄ

³

DIGITAL VOLT

³

³³ ³

METER

³

ÚÄij³Ä¿ ³

ЪДДДДДДДД¿

³

³

³³ ³ АДДДДДДДДЩ

³

³

³³ ³

+ve -ve

³

³

³³

Pin 22

АДДВДДДДДДВДДЩ

DAC0 OUTPUT

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

³

³³

³

DAC0 GROUND

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

³³

Pin 23

³ ³³
³

³³

ÀÄij³ÄÙ

ÄÄÄÄ¿ ÚÄÄÙ³

АДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

Figure 4-3. DAC Calibration Values.________________________________

ЪДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

³

ANALOGUE OUTPUT RANGE

³

³

DIGITAL

ГДДДДДДДДДДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´

³

OUTPUT ³ UNIPOLAR

³

BIPOLAR

³

³

CODE

ГДДДДДДДДДДВДДДДДДДДДДЕДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДД´

³

³ 0 to +5V ³ 0 to +10V³ +/-2.5V ³ +/-5V ³ +/-10V

³
ГДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДД´
³

FFF hex ³ +4.9987V ³ +9.9976V ³ +2.4987V ³ +4.9987V ³ +9.9951V

³
³

000 hex ³ 0.0000V ³ 0.0000V ³ -2.5000V ³ -5.0000V ³-10.0000V

³
³

1 LSB ³ 1.22mV ³ 2.44mV ³ 1.22mV ³ 2.44mV ³ 4.88mV

³
³

1/10LSB ³ 0.122mV ³ 0.244mV ³ 0.122mV ³ 0.244mV ³ 0.488mV

³
³

1/10LSB ³ 0.0001V ³ 0.0002V ³ 0.0001V ³ 0.0002V ³ 0.0005V

³
АДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДЩ

DAC1 Calibration Procedure.__________________________

i) Set up the DAC1 output jumpers for the output range

required, make a note of the output range.

ii) Using leads as short as possible connect up the digital

voltmeter as in Figure 4-4

iii) Set DAC1 to its LOWEST output value by writing the

digital code 000 hex to the converter.

iv) Using Figure 4-3 determine the ideal output voltage for the

000 hex input code, the 1/10 LSB value is the precision

Chapter 4 Page 75

AD1200 Reference Calibration

required. This is the OFFSET adjustment.
For BIPOLAR ranges adjust trim pot 8 for minus full scale
value. eg for range -5 to +5 bipolar the ideal offset voltage
is -5.0000 Volts +/- 0.0002 Volt.
For UNIPOLAR ranges adjust trim pot 9 for zero volts.
eg for range 0 to +5 unipolar the ideal offset voltage is

0.0000 Volts +/- 0.0001 Volt.

v) Set DAC1 to its HIGHEST output value by writing the

digital code FFF hex to the converter.

vi) Using Figure 4-3 determine the ideal output voltage for the

FFF hex input code, the 1/10 LSB value is the precision
required. This is the GAIN adjustment.
Adjust trim pot 7 for maximum positive output voltage.
eg for range -5 to +5 bipolar the ideal full scale voltage is
+4.9987 Volts +/- 0.0002 Volt.
eg for range 0 to +5 unipolar the ideal full scale voltage is
+4.9987 Volts +/- 0.0001 Volt.

Figure 4-4. DAC1 Calibration Wiring Diagram._________________________________________

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿ ЪДДДДДДДДДДДД¿

³ÚÄÄ

³

DIGITAL VOLT

³

³³ ³

METER

³

ÚÄij³Ä¿ ³

ЪДДДДДДДД¿

³

³

³³ ³ АДДДДДДДДЩ

³

³

³³ ³

+ve -ve

³

³

³³

Pin 24

АДДВДДДДДДВДДЩ

DAC1 OUTPUT

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

³

³³

³

DAC1 GROUND

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

³³

Pin 25

³ ³³
³

³³

ÀÄij³ÄÙ

ÄÄÄÄ¿ ÚÄÄÙ³

АДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

Page 76 Chapter 4

Calibration AD1200 Reference

Calibrating The Analogue To Digital Input.______________________________________

There is only one analogue to digital converter on the
AD1200 card. The 8 or 16 channels of analogue input are
provided by using a multiplexer to switch one of the possible
inputs to the ADS774/574 chip, thus the calibration need only be
performed on one input channel. This section assumes that
channel one has been chosen.

Figure 4-5. ADC Trimmer Pot Layout.__________________________________

ÚÄÄÄ

ADC

ÄÄÄ¿

GAIN

³

BPOFFSET

³ ³

UNIOFFSET

æ ææ
ЪДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³ ÚÁ¿ÚÁ¿

ÚÁ¿

³ÚÄ

³³

³³ ³ ³ ³³³

³ АДЩАДЩ

ÀÄÙ ÚÄij³Ä¿

³

POT3 POT1

³³³

³

POT2

³³³
³ ³³³
³

NOTE THESE POTS ARE IN A DIFFERENT

³³³
³

ORDER ON PREVIOUS VERSIONS OF THESE

³³³
³

CARDS

³³³
³

AD1200 PRIOR TO REV 5

³³³
³

AD1210 PRIOR TO REV 4

³³³
³

AD1200 PRIOR TO REV 4

ÀÄij³ÄÙ
АДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿ ÚÄÄÙ³

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДЩ ³

Outline._______

The calibration is simple. It consists of only two steps.

i) Using a precision voltage source set the input voltage

precisely at 1/2 LSB above the "all bits off" specified
input. Then adjust the OFFSET trim potentiometer to so
that the converter just switches in its LSB. IE the ADC
input switches from 0000 0000 0001 to 0000 0000 0000
binary, 01 to 00 hex.

ii) Using a precision voltage source set the input voltage

precisely at 1/2 LSB less than the "all bits on" specified
input. Then adjust the GAIN trim potentiometer so that the
converter just switches in its LSB. IE the ADC input
switches from 1111 1111 1110 to 1111 1111 1111 binary,

Chapter 4 Page 77

AD1200 Reference Calibration

FE to FF hex.

Provided the calibration is performed in the correct order,
OFFSET adjust then GAIN adjust, there should be no interaction
between the two adjustments.

Equipment Required.___________________

A precision voltage source capable of a stable output and
resolution of 1/10th of LSB at both ends of the range of the
converter . Thus the voltage source should have a range of -5 to
+10 volts and a resolution of 1.22mV/10 = 122uV or better.

Figure 4-6. ADC Calibration Wiring Diagram.________________________________________

ЪДДДДДДДДДДДД¿
³

PRECISION

³

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿ ³

VOLT SOURCE

³

³ÚÄÄ ³

ЪДДДДДДДД¿

³

³³ ³

АДДДДДДДДЩ

³

ÚÄij³Ä¿ ³

+ve -ve

³

³

³³

Pin

АДДВДДДДДДВДДЩ

CH0 INPUT

ДДДДДДДДДДДДДД±±±ДДДДДДДДДДДДДЩ

³

³

³³

Pin

³

CH8 ( =CH0 RET) INPUT

ДДДДДДДДДДДДДД±±±ДВДДДДДДДДДДДДДДДДДДЩ

³

³³

³

CH1-CH7, CH9-CH15

ДДДДДДДДДДДДДД¿

³

³

³³

³

³

AGND

ДДДДДДДДДДДДДДБДД±±±Д´

³

³³

³

AMP LO

ДДДДДДДДДДДДДДДДД±±±ДЩ

ÀÄij³ÄÙ

ÄÄÄÄ¿ ÚÄÄÙ³

АДДДДДДДДДДДДДДДДДДДДДДДДДЩ

³

ADC Calibration Procedure._________________________

i) Set up the ADC input jumpers for the input range required,

make a note of the input range.

ii) Using leads as short as possible connect up the digital

voltmeter as in Figure 4-5

iii) Using Figures 4-7 & 4-8 determine the precision voltage

source output for the 1/2 LSB code above that producing
the 000 hex output code, the 000+1/2LSB value.

Page 78 Chapter 4

Calibration AD1200 Reference

iv) Adjust the OFFSET trimpot so that the input code from the

A/D converter flickers evenly between 00hex and 01hex.
This is the OFFSET adjustment.
For BIPOLAR ranges adjust trim pot 2 for 00hex to 01hex
transition. eg for range -5 to +5 bipolar the 000+1/2LSB
voltage is -4.9988 Volt.
For UNIPOLAR ranges adjust trim pot 1 for 00hex to
01hex transition. eg for range 0 to +5 unipolar the
000+1/2LSB voltage is 610 uVolt.

v) Using Figures 4-7 & 4-8 determine the precision voltage

source output for the 1 1/2 LSB code below FSR, the Full
Scale Reading, the FSR-1.5LSB value.

vi) Adjust the GAIN trimpot so that the input code from the

A/D converter flickers evenly between FEhex and FFhex.
This is the GAIN adjustment.
Adjust trim pot 3 for for FEhex to FFhex transition.
eg for range -5 to +5 bipolar the FSR-1.5LSB value is
+4.9963 Volts.
eg for range 0 to +5 unipolar the FSR-1.5LSB value is
+4.9982 Volts.

Figure 4-7. Unipolar ADC Calibration Values.________________________________________

ЪДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

³

ANALOGUE INPUT RANGE

³

³

DIGITAL

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´

³

OUTPUT

³

UNIPOLAR

³

³

CODE

ГДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДД´

³

³

0 to 1.25³ 0 to+2.5V³ 0 to +5V ³ 0 to +10V

³
ГДДДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДД´
³

FSR

³

+1.2500V ³ +2.5000V ³ +5.0000V ³+10.0000V

³
³

FSR-1LSB

³

+1.2497V ³ +2.4994V ³ +4.9988V ³ +9.9976V

³
³

FSR-1.5LSB

³

+1.2495V ³ +2.4991V ³ +4.9982V ³ +9.9963V

³
ГДДДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДД´
³

000 hex

³

0.0000V ³ 0.0000V ³ 0.0000V ³ 0.0000V

³
³

1 LSB

³

0.305mV ³ 0.61mV ³ 1.22mV ³ 2.44mV

³
³

1/2 LSB

³

0.153mV ³ 0.305mV ³ 0.61mV ³ 1.22mV

³
³

000+1/2LSB

³

153uV ³ 305uV ³ 610uV ³ 1220uV

³
АДДДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДЩ

Chapter 4 Page 79

AD1200 Reference Calibration

Figure 4-8. Bipolar ADC Calibration Values._______________________________________

ЪДДДДДДДДДДДДВДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿
³

³

ANALOGUE INPUT RANGE

³

³

DIGITAL

ГДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД´

³

OUTPUT

³

BIPOLAR

³

³

CODE

ГДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДДВДДДДДДДДДД´

³

³

+/-0.625V³ +/-1.25V ³ +/-2.5V ³ +/-5V ³ +/-10V

³
ГДДДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДД´
³

FSR

³

+0.6250V ³ +1.2500V ³ +2.5000V ³ +5.0000V ³+10.0000V

³
³

FSR-1LSB

³

+0.6247V ³ +1.2494V ³ +2.4988V ³ +4.9976V ³ +9.9951V

³
³

FSR-1.5LSB

³

+0.6245V ³ +1.2491V ³ +2.4982V ³ +4.9963V ³ +9.9927V

³
ГДДДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДДЕДДДДДДДДДД´
³

000 hex

³

-0.6250V ³ -1.2500V ³ -2.5000V ³ -5.0000V ³-10.0000V

³
³

1 LSB

³

0.305mV ³ 0.610mV ³ 1.22mV ³ 2.44mV ³ 4.88mV

³
³

1/2 LSB

³

0.153mV ³ 0.305mV ³ 0.61mV ³ 1.22mV ³ 2.44mV

³
³

000+1/2LSB

³

-0.6249V ³ -1.2497V ³ -2.4994V ³ -4.9988V ³ -9.9976V

³
АДДДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДБДДДДДДДДДДЩ

Page 80 Chapter 4

Technical Specification AD1200 Reference

CHAPTER 5

TECHNICAL

SPECIFICATION.

Introduction.____________

This chapter gives the complete technical specification for

the AD1200 range of cards.

Analogue Inputs._______________

Input Impedance On Channel 100M Ohms, 100pF.

Off Channel 100M Ohms, 10pF.
Maximum Common Mode
Input Voltage 11V
Common Mode 80 dB at 60Hz, gain of 1.
Rejection Ratio 120 dB at 60Hz, gain of 1000.
Maximum Input Voltage ±30V power on

±30V power on
Resolution 12 bits
Nonlinearity less than 1/2 LSB
Differential nonlinearity less than 1/2 LSB
Quantised Uncertainty ± 1/2 LSB
Offset drift 10 ppm/degree C
Gain drift 30 ppm/degree C
Offset Error Adjustable to zero
Gain Error Adjustable to zero

Input Channels 16 Single Ended
(jumper OR 8 Differential

selectable) OR 16 Pseudo Diff

Channel Select Programmable
Bipolar Input ±5Volt, ±2.5Volt
Unipolar Input 0~10Volt, 0~5Volt

Chapter 5 Page 81

AD1200 Reference Technical Specification

Throughput 30kHz AD1221, AD1211.

100kHz AD1220, AD1210 &
AD1200 gains 1-2-4-8-10-100.
800kHz AD1220, AD1210 and
AD1200 gain 1000.

Conversion Time 25uS AD1221, AD1211.

8.5uS AD1220, AD1210 &
AD1200

System Accuracy ± 0.03% Gain=1

± 0.035% Gain=2
± 0.04% Gain=4
± 0.05% Gain=8
± 0.05% Gain=10
± 0.07% Gain=100
± 0.10% Gain=1000

Monotonicity 0 to 70 degree C

Analog Outputs______________

Resolution 12 bits
Bipolar Output ±10V, ±5V, ±2.5V
Unipolar Output 0~10Volt, 0~5Volt
Nonlinearity less than 1/4 LSB
Differential nonlinearity less than 1/2 LSB
Quantised Uncertainty ± 1/2 LSB
Offset drift ±5 ppm/degree C
Gain drift ±2 ppm/degree C
Offset Error Adjustable to zero
Gain Error Adjustable to zero
Settling Time to 0.01% 3 microseconds
Throughput 100kHz per DAC
System Accuracy 0.025%
Monotonicity 0 to 70 degree C

Digital I/O__________

TTL output 8 bit
TTL input 8 bit

Page 82 Chapter 5

Technical Specification AD1200 Reference

Throughput 1MHz
Fan in 1 LS load
Fan out 10 LS loads

Pacer Clock.___________

Pacer Clock 0.005Hz-600kHz
Divisor 1 to 120,000,000
External Clock TTL compatible. DC to 1Mhz.
External Trigger TTL compatible, active on negative

edge.

Power Consumption.__________________

+5 Volts ±5% 500 milli Amp 2.5 Watt
+12 Volts ±5% 50 milli Amp 0.6 Watt

-12 Volts ±5% 40 milli Amp 0.5 Watt
Dimensions. 4.2 x 8.8 inches.

Chapter 5 Page 83

Index AD1200 Reference

Index.______

+12/-12.............................47, 83

12 bit.................................2, 4, 7, 10, 11, 20, 60, 61, 62, 63, 64

16 bit.................................7, 24, 43, 45, 62, 64

4-20mA.............................22, 23

8 bit...................................2, 7, 21, 24, 45, 60, 62, 63, 65, 66, 82

A/D control status reg.......16, 17, 18, 19, 20, 21, 51, 52, 53, 56

A/D Done.........................2, 5, 12-13, 17-19, 53, 55, 57, 61, 62

A/D error..........................15, 52, 53, 54, 55, 57

A/D gain channel reg........10, 11, 17, 18, 19, 58

A/D modes........................17

A/D strobes.......................18, 19, 54

Accuracy...........................82

Ad1200 card.....................1, 3, 5, 10, 14, 17-21, 24, 25, 26, 27,

33, 34, 35, 36, 37, 38, 39, 40, 45, 47,

48, 49, 50, 54, 55, 56, 66, 69, 72, 77

AD1200L..........................4

AD1210............................1-4, 14-15, 26, 41, 43, 54, 67, 70, 77

AD1211............................1, 3, 14, 15, 26, 41, 43, 54, 67, 82

AD1220............................1, 3, 11, 14-15, 26, 42-43, 54, 58-59,82

AD1221............................1-3, 11, 14-15, 26, 42-43, 54, 58-59,

67, 82

Adapter.............................28, 29

ADC..................................17, 22, 25, 26, 37, 38, 39, 40, 41, 42,

53, 54, 56, 61, 62, 77, 78, 79, 80

ADCHI.............................12-13, 15, 17-19, 51, 54, 57, 60-62

ADCLO............................12, 13, 15, 17, 18, 19, 51, 54, 60, 61

ADCSR.............................16-22, 51-54, 56, 57, 62, 67, 69

ADGCR............................10-11, 16-20, 22, 51, 52, 56, 58, 59

Adjustment.......................74, 76, 79

AGND..............................9, 47, 48, 49, 50, 78

Analogue ground..............9, 47, 48, 49, 50

Analogue output...............7, 20, 22, 47, 49, 61-63, 72, 75

Aperture............................45

ATB..................................22, 23

Index Page 1

AD1200 Reference Index

Base address.....................27, 29, 70

Binary...............................28, 61, 62, 64, 77

Bipolar..............................2, 5, 8, 10, 20, 25-26, 37-42, 61, 63,

64, 74-76, 79-82

Bit weights........................8

Bits....................................6-8, 12, 16-22, 52-53, 55-60, 62-65,

67, 68, 69, 70, 77, 81, 82

Cable.................................22, 23, 46, 47

Cables...............................9, 23, 46, 49, 72

Calibration........................37, 42, 72-80

Channel select...................2, 58, 59, 60, 81

Clear error.........................53

Clock divisor....................18, 19, 67, 68

Connection........................49

Connectors........................49

Continuous conversion.....17, 57, 70

D/A converter...................4, 14, 20, 47, 52, 61, 62, 63, 64, 73

DAC0................................5, 17, 20, 25-26, 37, 46-52, 54-57, 61,

62, 63, 67, 70, 72, 73, 74, 75

DAC0 ground...................46, 47, 49

DAC0HI...........................62

DAC0LO..........................62, 63

DAC1................................5, 17, 20, 25-26, 37, 46-52, 54-57, 63,

65, 67, 70, 72, 73, 75, 76

DAC1 ground...................46, 47, 49

DAC1HI...........................52, 63, 64

DAC1LO..........................52, 64

Differential.......................2, 8-10, 38, 39, 47, 49, 50, 60, 81, 82

DIGIN...............................17, 22, 66

Digital i/o..........................2, 17, 21-22, 34, 51, 56, 57, 67, 70, 82

Digital input......................4, 20-21, 24, 43, 48-49, 52, 66-67, 71,

77

Digital output....................4, 21, 33, 48, 49, 52, 65

DIGOUT...........................17, 22, 65

Divisor..............................18, 19, 20, 22, 67, 68, 69, 83

DMA.................................1-5, 10, 12-22, 24-25, 27, 33, 35-37,

Page 2 Index

Index AD1200 Reference

48, 53, 54, 55, 57

DMA enable.....................16, 36, 53, 54

DMA jumper....................24, 25, 36, 37

DMAJMP.........................36

Drift..................................81, 82

DT2811.............................1, 3, 4, 5, 52

Error..................................9, 15, 52, 53, 54, 55, 57, 81, 82

Extended mode.................17, 20, 51, 55, 56, 57, 66, 67, 69, 70

Extended modes................67

External clock...................2, 16, 19, 21, 22, 46, 48, 56, 67, 83

External trigger.................2, 18, 19, 20, 22, 46, 48, 83

Extreme............................1, 8, 37

Fan in................................83

Fan out..............................83

Frequency.........................14, 18, 19, 20, 22, 48, 66, 67, 68, 69

FSR...................................79, 80

Gain.................................. 1-5, 10-15, 17-19, 26, 38, 40-42, 49-51

58-59, 73, 74, 76, 77, 78, 79, 81, 82

Gain error.........................81, 82

Gain select........................26, 58

Gain trim...........................73, 77

Guarantee..........................29

High byte..........................12, 51, 54, 57, 62, 63, 65

I/o base address.................27

Input ranges......................11, 40, 41, 42

Input voltage.....................10, 11, 12, 38, 39, 50, 58, 59, 77, 81

Interfaces..........................47

Interrupt jumper................25, 34

Interrupt service routine....12, 15, 17, 18, 19, 21, 22

IRQ jumper.......................34, 35

IRQJMP............................34

ISR....................................12, 13

Index Page 3

AD1200 Reference Index

Justified.............................61, 62, 64

Logic level........................65, 66

Low byte...........................12, 51, 61, 63, 65

LSB...................................73, 74, 75, 76, 77, 78, 79, 80, 81, 82

Maximum throughput.......67

Memory............................6, 10, 12, 13, 15, 36

Mode 0..............................16, 17, 56, 58, 67, 69

Mode 1..............................18, 20, 21

Mode 2..............................18

Mode 3..............................19

Mode bit 0.........................55, 56

Mode bit 1.........................55

Monotonicity....................82

Multimeter........................72

Multiplexer.......................10, 11, 14, 77

Noise.................................9, 23, 49

Nonlinearity......................81, 82

Offset................................61-64, 73-74, 76-79, 81, 82

Offset binary.....................61, 62, 64

Offset error.......................81, 82

Offset trim........................73, 77

Oscillator..........................14, 16, 18-19, 21-22, 43, 48, 56, 67-69

Pacer clock........................2, 10, 12-22, 43, 54-58, 66-71, 83

PGA..................................11, 12

Pipeline.............................15

Pipelining..........................14, 15

Polled i/o...........................12

Port...................................4, 17, 21, 28, 35, 43, 48, 51, 52, 55,

56, 57, 65, 66, 67, 69, 70, 71

Power................................14-15, 22, 44, 46-48, 50, 53-56, 59-60,

81, 83
Precision voltage source...77, 78, 79

Problems...........................50

Page 4 Index

Index AD1200 Reference

Programmable gain...........1, 2, 3, 4, 5, 10, 11, 14, 49, 50, 58, 59

Programmable gain amp...10, 11, 14, 49, 50, 58

Programmed i/o................10, 12, 14, 17, 18, 19, 20, 21

Pseudo differential............10, 38, 47, 60

Reference..........................1

Register map.....................51, 52, 71

Resolution.........................6, 7, 8, 10, 73, 78, 81, 82

Sample and hold...............9, 58

Sampling A/D...................9

Screw terminal board........22, 23

Settling time......................10, 11, 14, 82

Shielded............................49, 50

Single conversion.............16, 58

Single ended.....................2, 8-10, 25, 38, 39, 47, 49, 50, 60, 81

Strobe................................14, 16-22, 54, 55, 56, 58, 70

Strobes..............................18, 19, 20, 21, 22, 54, 55, 67, 71

Technical..........................81

Temperature......................5, 10, 72

Throughput.......................1, 2, 3, 4, 5, 14, 15, 67, 82, 83

Time Electronics...............72

Timer................................14-21, 26, 28, 31, 43, 51, 55-7, 66-71

TIMEREX........................66, 67, 69

Traceable..........................37, 42, 72

Trigger.............................. 2, 13, 15-16, 18-20, 22, 46, 48, 54, 56,

71, 83

Trimpot.............................79

TTL compatible................14, 21, 48, 83

Twisted pair......................9, 49

Uncertainty.......................81, 82

Unipolar............................2, 5, 8, 10, 20, 37-38, 40-42, 61, 63,

64, 74-76, 79-82

Voltmeter..........................72, 73, 74, 75, 78

Warning............................50

Xmode..............................16, 17, 20, 21, 43, 67, 69, 71

Index Page 5