Measurement CIO-DAS16 User Manual

CIO-DAS16

CIO-DAS16/F

USER’S MANUAL

Revision 8

October, 2000

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HM CIO-DAS16.lwp

1 INSTALLATION

TABLE OF CONTENTS

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2 SIGNAL CONNECTION

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4 CIO-DAS16 CONTROL & DATA REGISTERS

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5 SPECIFICATIONS

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1
1 1.1 BASE ADDRESS
2 1.2 MODIFYING THE CIO-DAS16 FOR ODD ADDRESSES
2 1.3 DMA LEVEL SELECT
2 1.4 1/10 MHz XTAL JUMPER
2 1.5 8/16 CHANNEL SELECT
3 1.6 D/A CONVERTER REFERENCE JUMPER BLOCK
3 1.7 RANGE SWITCH SETTING
5
5 2.1 CONNECTOR DIAGRAM
6 2.2 ANALOG INPUTS
8 2.3 ANALOG OUTPUTS
8 2.4 DIGITAL OUTPUTS & INPUTS
93 ANALOG CONNECTIONS
9 3.1 ANALOG INPUTS

9 3.2 SINGLE-ENDED AND DIFFERENTIAL INPUTS
13 3.3 WIRING CONFIGURATIONS
18
19 4.1 INTRODUCTION
19 4.2 A/D DATA & CHANNEL REGISTERS
20 4.3 CHANNEL MUX SCAN LIMITS REGISTER
20 4.4 4-BIT DIGITAL I/O REGISTERS
21 4.5 D/A REGISTERS
22 4.6 STATUS REGISTER
23 4.7 DMA, INTERRUPT & TRIGGER CONTROL
23 4.8 PACER CLOCK CONTROL REGISTER
24 4.9 BASE + 11 - RESERVED REGISTER
24 4.10 PACER CLOCK DATA & CONTROL REGISTERS
25 4.11 24-LINE DIGITAL I/O REGISTERS
28

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1 INSTALLATION

Before you open your computer and install the board, install and run InstaCal™, the installation, calibration and test
utility included with your board. InstaCal™ will guide you through switch and jumper settings for your board. Detailed
information regarding these settings can be found below. Refer to the Software Installation manual for InstaCal™
installation instructions.

There are two versions of this board, the CIO-DAS16 and the CIO-DAS16/F. The only difference between the two is
maximum sampling rate for the A/D. They will both be referred to as the CIO-DAS16 except where this distinction
applies.

The CIO-DAS16 has one bank of switches, two single function switches and four jumper blocks which must be set before
installation of the board inside your computer.

1.1 BASE ADDRESS

After a base address is chosen, a diagram of the switch setting is drawn on the PC screen. Set the switches on your base
address switch as shown on Figure 1-1. Unless there is already a board in your system which uses address 300 hex (768
decimal) then you can leave the switches as they are set at the factory.

In the diagram, the CIO-DAS16 is set for base address 300h. That means the
DAS-16 compatible section of the board is at 300h and the PIO-12 compatible
section of the board is at 310h (784 Decimal).

When the 4 addresses of the 8255 digital I/O (PIO-12) are in use, the
CIO-DAS16 occupies 20 consecutive addresses and is addressable on 32 address
boundaries. Address boundaries of 32 are 300h, 320h, 340h, 360h, etc.
Figure 1-1. Base Address Switches

Because the MetraByte DAS-16 occupies only 16 addresses, it is addressable at 300h, 310h, 320h, 330h etc. If you have
written software that assumes the DAS-16 base address is on a 16 address boundary and it is too much trouble to change
the address in software, the CIO-DAS16 can be made to occupy only 16 addresses and address on 16 address boundaries.

If you want to address the CIO-DAS16 on a 16 boundary address, such as 310h, 330h, 350h etc., you will not be able to
use the additional 24 digital I/O lines on the rear connector.

1.2 MODIFYING THE CIO-DAS16 FOR COMPATIBLE ADDRESSES

There are two jumpers on the CIO-DAS16, J3 and J4, which disable or enable the 8255. The jumpers must be configured
as a pair, according to either the (A) or (B) configuration in Figure 1-2.

J3J4

(A)CIO-DAS16 POSITION

PIO-12 is active at Base Address + 16

Board will address at 300H, 320H, 340H, etc.

Board will address at 300H, 310H, 320H, etc.

J4

(B) DAS 16 POSITION

PIO-12 is not active at any address.

J3

CIO-DAS16 PIO-12 KNOCK OUT JUMPERS - The CIO-DAS16 is shipped in the (A)
configuration. It should be left this way unless you want to use odd addressess,
such as 310H, 330H, 350H, etc. In the (B) configuration, the 24 digital lines of
the 8255 are not usable.

Figure 1-2. Odd Address Jumpers

1

1.3 DMA LEVEL SELECT

What kind of computer are you installing the board in? If it is an old XT then there are only two DMA levels available
and level 3 is probably used by the hard disk controller in your XT computer. Set the
DMA level switch to the level 1 position (Figure 1-3).

If you have an AT or 386 type computer the hard disk controller is not at level 1 or 3
so either level may be used.

There are other boards that use DMA levels. Some network boards and some
IEEE-488 interface boards do also. If you have other boards in your computer with
DMA level switches on them, they must have a different level setting.

Figure 1-3. DMA Level Select Switch

1.4 1/10 MHZ XTAL JUMPER

The 1/10 MHz XTAL jumper selects the frequency of the source applied to the
on-board pacer. This pacer is used to pace the A/D start conversion trigger.

This jumper is on the board because the original DAS-16, designed in 1984, had
a 1 MHz crystal. When MetraByte redesigned the DAS-16 and added the faster
10 MHz crystal, a jumper was provided to maintain compatibility with older
software. The CIO-DAS16 has the jumper because the DAS-16 has the jumper
and some software needs the jumper to be in the 1 MHz position and some
software requires the 10 MHz position.

Figure 1-4. 1 or 10 MHz Xtal Jumper
The CIO-DAS16 is shipped with the jumper in the 1 MHz position.
Some older 3rd party software programs require that the jumper be in the 1 MHz position. Please refer to the software

program user's manual for guidance. Other programs, such as Labtech Notebook, have a 1 or 10 MHz choice in the
set-up menu.

1.5 8/16 CHANNEL SELECT

The analog inputs of the CIO-DAS16 may be configured as 8 differential or 16
single-ended. Using single-ended inputs means you have more separate analog
input channels available to connect signals. Using differential inputs allows up to
10 volts of common mode (ground loop) rejection and can be more noise immune.

The CIO-DAS16 comes from the factory configured for 8 differential inputs so the
8/16 switch is in the position shown here. Set it for the type and number of inputs
you desire.

Figure 1-5. 8 /16 Channel Select Switch

2

1.6 D/A CONVERTER REFERENCE JUMPER BLOCK

There is a jumper block with 10 pins (2 rows of 5 each) located top center on the board. This block allows you to use the
on-board precision voltage reference or an external voltage to provide reference to either or both of the digital-to-analog
converters.

If you choose to use the on-board voltage reference rather than an external voltage, two D/A reference input pins, 10 and
26, on the 37-pin connector are not needed as reference inputs.

The 'S' jumper in this block is used to place a synchronizing signal on pin 26 so that the CIO-SSH16 external accessory
Simultaneous Sample & Hold board can be used.

If the on-board D/A reference is used, the jumpers are set in the I1 and I0
positions (Figure 1-6). The board is configured this way at the factory. The
SS&H output is not connected. If an external reference is desired, move the
blocks to X0 and X1. If using a CIO-SSH16 board, leave the blocks on I0
and I1 and place a block on SS&H. To avoid possible damage in the event
of a bad connection, do not install jumper S unless you intend to connect a
CIO-SSH16 board. There is a spare shorting block on one of the 'S' pins.

Figure 1-6. Ref. Volt and SS&H Jumpers

D/A 1

EXTERNAL &

INTERNAL

X I1 S I0 X

D/A 0

INTERNAL &

EXTERNAL

1.7 RANGE SWITCH SETTING

A bank of six dip switches accessible through the CIO-DAS16 connector bracket control the UNIPOLAR/BIPOLAR
analog input range (Figure 1-7).

SW #

UNIPOLAR

LEFT

NO USER GAIN

These switches control the analog input range values of all channels. You can use Table 1-1 and Figure 1-7, or use the

Cal program to determine the correct positions of switches S1 through S6 for the range you desire.

Insta

.

6
5
4
3
2
1

The factory setting of +/- 5V

BIPOLAR - SW 6 ONLY

SW 2 - 4
SELECT THE RANGE

USER GAIN SELECTED

shown.

Figure 1-7. Range Select Switches

SEE TABLE 1-1

3

Table 1-1. Range Select Switch Positions

GAINS5S4S3S2S1

In the above table R = right and L = left.

BIPOLAR

S6=RIGHT

S6=LEFT

RESOLUTIONUNIPOLAR

4.88mV / bitN/A+/- 10V0.5LLLLL

2.44mV / bit0 to 10V+/- 5V1RLLLL

1.22mV / bit0 to 5V+/- 2.5V2RRLLL

0.488mV / bit0 to 2 V+/- 1V5RLRLL

0.244mV / bit0 to 1V+/- 0.5V10RLLRL

SEE EQUATION0.5 < USER < 20LLLLR

S6, the top switch, controls a relay that switches the range between unipolar and bipolar.
Set the switches as desired or leave them at the factory setting of +/- 5 volts.
It is not necessary to turn off the PC power or disconnect signals when changing these switch settings.

4

2 SIGNAL CONNECTION

2.1 CONNECTOR DIAGRAM

The CIO-DAS16 analog connector is a 37-pin, D-type connector accessible from the rear of the PC through the expansion
backplate (Figure 2-1). The signals available are identical to the DAS-16, or optionally, an additional signal, SS&H
OUT, may be accessed at pin 26.

UNIPOLAR

RR

LR
LR LL
LLRL
LL L

GAIN = 0.5 2 5 10

CH0 LOW/CH8 HIGH 18

CH1 LOW/CH9 HIGH 17
CH2 LOW/CH10 HIGH 16
CH3 LOW/CH11 HIGH 15
CH4 LOW/CH12 HIGH 14
CH5 LOW/CH13 HIGH 13
CH6 LOW/CH14 HIGH 12
CH7 LOW/CH15 HIGH 11

LLGND 19

D/A 0 REF 10

D/A 0 OUT 9

-5V REF 8
GND 7

DIG. IN 1 6

DIG. IN 3 5
DIG. OUT 1 4
DIG. OUT 3 3
CTR 0 OUT 2

+5V PC BUS 1

R

BIPOLAR
R

GAIN = 1

L

+/- 5V RANGE

L
L

USER GAIN RESISTOR

37 CH0 HIGH
36 CH1 HIGH
35 CH2 HIGH
34 CH3 HIGH
33 CH4 HIGH
32 CH5 HIGH
31 CH6 HIGH
30 CH7 HIGH
29 LLGND
28 LLGND
27 D/A 1 OUT
26 D/A 1 REF/SS&H OUT
25 DIG. IN 0/TRIGGER
24 DIG. IN 2/CTR0 GATE
23 DIG. OUT 0
22 DIG. OUT 2
21 CTR 0 CLOCK IN
20 CTR 2 OUT

CIO-DAS16 ANALOG CONNECTOR - The CIO-DAS16
analog connector can be accessed from the rear of
the computer through the expansion backplate.

Figure 2-1. Analog Connector

If frequent changes to signal connections or signal conditioning is required, please refer to the information on one of the
following:

y

CIO-TERMINAL screw terminal board

y

CIO-EXP16, 16-channel analog multiplexer

y

CIO-SSH16 16-channel simultaneous sample & hold board

y

ISO-RACK16, 16-module 5B isolation module interface rack

The CIO-DAS16 digital connector is identical to the CIO-DIO24 connector except for the −12V and +12V power signals
and interrupt input brought out on the CIO-DIO24. These are no-connect pins on the CIO-DAS16.

The digital connector is mounted at the rear of the CIO-DAS16 and will accept a 37-pin, D-type female connector such as
those on the C73FF-2, two-foot cable with connectors.

5

A BP-37 will bring the signals to a backplate with a 37 pin male connector

g1g

mounted in it.

A standard C37FF-2 may be run alongside the analog connector through the
gap in the expansion slot backplate, or may be connected to the BP-37.

2.2 ANALOG INPUTS

Analog inputs to the CIO-DAS16 can be connected in three different
configurations:

y

Single-Ended

y

Floating Differential

y

Differential.

WARNING - PLEASE READ

Measure the voltage between the ground signal at the signal source and the PC. Using a voltmeter, place
the red probe on the PC ground and the black probe on the signal ground. If there is more than 10 volts
(AC or DC), do not connect the CIO-DAS16 to this signal source because you will not be able to make
any reading. If more than 30 volts, DO NOT connect this signal to the CIO-DAS16 because it will
damage the board and possibly the computer. Voltages over 24V can be hazardous. Use great care

when measuring voltages.

19

GND

+5V

GND

NC

GND

NC

GND

NC

GND
PORT B 0
PORT B 1
PORT B 2
PORT B 3
PORT B 4
PORT B 5
PORT B 6
PORT B 7

NC
NC

18
17
16
15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

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

PORT A 0
PORT A 1
PORT A 2
PORT A 3
PORT A 4
PORT A 5
PORT A 6
PORT A 7
PORT C 0
PORT C 1
PORT C 2
PORT C 3
PORT C 4
PORT C 5
PORT C 6
PORT C 7
GND
+5V

CIO-DAS16 DIGITAL CONNECTOR - The connector
is mounted at the rear of the CIO-DAS 16.

Figure 2-2. Digital Connector

SINGLE-ENDED
A single-ended input has two wires connected to the CIO-DAS16; a channel high (CH# HI) and a Low Level Ground
(LLGND). The LLGND signal must be the same ground the PC is on. The CH# HI is the voltage signal source.

DIFFERENTIAL

Vs+Vcm

AMP

+

-

+

-

2

TO A/D

GND

S

I
G
N
A
L

V+

Vs

37
36
35
34

LL GND

CH 0 HI

HI

G

19
18
17
16
15

SIGNAL ENDED INPUT - A channel high (CH 0 HI) and a low level ground
(LLGND) are connected to the CIO-DAS16.

Figure 2-3. Single-Ended Input Configuration

6

FLOATING DIFFERENTIAL
A floating differential input is two wires from the signal source and a

10K ground reference resistor installed at the CIO-DAS16 input. The
two signals from the signal source are Signal High (CH# HI) and
Signal Low (CH# LO) (Figure 2-4).

The reference resistor is connected between the CIO-DAS16 CH# LO
and LLGND pins.

A floating differential hookup is useful when the signal source is
floating with respect to ground, such as a battery, 4-20 mA transmitter
or the lead lengths are long or subject to EMI.

The floating differential input will reject up to 10V of EMI.

WARNING!

Verify that the signal source is floating. Check it with a voltmeter before risking the CIO-DAS16 and PC!

DIFFERENTIAL

10K OHM

-

+

BATTERY

CIO-DAS16 FLOATING DIFFERENTIAL - The two
signals from the signal source are Signal High
(CH 0 HI) and Signal Low (CH 0 LO).

LL GND

19

CH 0 HI

37

CH 0 LO

18

36

17

35

16

34

15

AMP

+

8

16

TO A/D

-

Figure 2-4. Floating Differential Input

DIFFERENTIAL
A differential signal has three wires from the signal source. The signals are Signal High (CH# HI), Signal Low (CH# LO)

and Signal Ground (LLGND) (Figure 2-5).
A differential connection allows you to connect the CIO-DAS16 to a signal source with a ground that is different from

the PC ground, but less than 10V difference, and still make a true measurement of the signal between CH# HI and CH#
LO.

DIFFERENTIAL

AMP

37

36

35

34

LL GND
CH 0 HI

CH 0 LO

8

19

V-

V+

18

17

GND

16

15

CIO-DAS16 DIFFERENTIAL - The signals are Signal High (CH 0 HI), Signal Low
(CH 0 LO), and Signal Ground (LLGND).

+

TO A/D

-

16

Figure 2-5. Differential Input
EXAMPLE:
A laboratory instrument with its own wall plug. There are sometimes voltages in wall GND between outlets.

7

2.3 ANALOG OUTPUTS

Analog outputs are voltage outputs which can be connected to any device which will record, display or be controlled by a
voltage.

The CIO-DAS16 analog outputs are 4 quadrant multiplying DACs. This means that they accept an input voltage reference
and provide an output voltage which is inverse to the reference voltage and proportional to the digital value in the output
register.

For example, the supplied reference of -5V provides a +5V output when the value in the output register is 4095 (full scale
at 12 bits of resolution). It provides a value of 2.5V when the value in the output register is 2048 (Figure 2-6).

D/A REFERENCE BLOCK

ISIX

X

D/A 0

ON BOARD -5 REF

V REF

V OUT =

V OUT

-1(V REF) * DATA

CIO-DAS16 37 PIN CONNECTOR

19

LLGND

18

D/A 0

-5 REF

10

9
8

D/A 0 REF

4096

37

28

LLGND

27

D/A 1

26

D/A 1 REF

GROUND

VOLTS OUT

CIO-DAS16 D/A CONVERTER SIGNAL CONNECTION - Jumper blocks for
internal Vref shown installed. The on-board -5V reference is internally
jumped. Both DACs will have a range of 0 to 5 volts. This is the factory

Figure 2-6. Analog Output Configuration

2.4 DIGITAL OUTPUTS & INPUTS

All the digital outputs and inputs on the CIO-DAS16 are TTL level. TTL is an electronics industry term, short for
Transistor Transistor Logic, that describes a standard for digital signals which are either at 0V or 5V (nominal). The
binary logic inside the PC is all TTL or LSTTL (Low power Schotky TTL).

8

3 ANALOG CONNECTIONS

3.1 ANALOG INPUTS

Although complete coverage of this topic is well beyond the scope of this manual, the following section provides some
explanations and helpful hints regarding these analog input connections. This section is intended to help you achieve the
optimum performance from your CIO-DAS16/F series board.

You should have a basic understanding of Single-Ended/Differential inputs and system grounding/isolation. If you are
already comfortable with these concepts you may wish to skip to the next section (on wiring configurations).

3.2 SINGLE-ENDED AND DIFFERENTIAL INPUTS

The CIO-DAS16/F provides either eight differential or 16 single-ended input channels. The concepts of single-ended and
differential inputs are discussed in the following section.

Single-Ended Inputs

A single-ended input measures the voltage between the input signal and ground. In this case, in single-ended mode the
CIO-DAS16/F measures the voltage between the input channel and LLGND. The single-ended input configuration
requires only one physical connection (wire) per channel and allows the CIO-DAS16/F to monitor more channels than the
(2-wire) differential configuration using the same connector and onboard multiplexor. However, since the CIO-DAS16/F
is measuring the input voltage relative to its own low level ground, single-ended inputs are more susceptible to both EMI
(Electro Magnetic Interference) and any ground noise at the signal source. Figure 3-1 shows the single-ended input
configuration.

Figure 3-1. Single-Ended Input Configuration

9

Differential Inputs

Differential inputs measure the voltage between two distinct input signals. Within a certain range (referred to as the
common mode range), the measurement is almost independent of signal source to CIO-DAS16/F ground variations. A
differential input is also much more immune to EMI than a single-ended one. Most EMI noise induced in one lead is also
induced in the other, the input only measures the difference between the two leads, and the EMI common to both is
ignored. This effect is a major reason there is twisted pair wire as the twisting assures that both wires are subject to
virtually identical external influence. Figure 3-2 below shows a typical differential input configuration.

Figure 3-2. Differential Input Configuration

10

Before moving on to the discussion of grounding and isolation, it is important to explain the concepts of common mode,
and common mode range (CM Range). Common mode voltage is depicted in Figure 3-2 as Vcm. Though differential
inputs measure the voltage between two signals, without (almost) respect to the either signal’s voltages relative to
ground, there is a limit to how far away from ground either signal can go. Though the CIO-DAS16/F has differential
inputs, it will not measure the difference between 100V and 101V as 1 Volt (in fact the 100V would destroy the board!).
This limitation or common mode range is depicted graphically in Figure 3-3. The CIO-DAS16/F common mode range is
+/- 10 Volts. Even in differential mode, no input signal can be measured if it is more than 10V from the board’s low level
ground (LLGND).

+13V
+12V
+11V
+10V
+9V
+8V
+7V
+6V
+5V
+4V
+3V
+2V
+1V

-1V

-2V

-3V

-4V

-5V

-6V

-7V

-8V

-9V

-10V

-11V

-12V

-13V

System Grounds and Isolation

Gray area represents common m ode range
Both V+ and V- must always re ma in w it h in
the common m ode range re la tiv e to L L Gn d

With Vcm= +5VDC,
+Vs must be less than +5V, or the common mod e range w ill be e x c eeded (>+10V)

Vcm

Vcm (Common M ode Voltage) = +5 Volts

Figure 3-3. Common Mode Range Diagram

There are three scenarios possible when connecting your signal source to your CIO-DAS16/F board.

1. The CIO-DAS16/F and the signal source may have the same (or common) ground. This signal source may be

connected directly to the CIO-DAS16/F.

2. The CIO-DAS16/F and the signal source may have an offset voltage between their grounds (AC and/or DC). This

offset it commonly referred to a common mode voltage. Depending on the magnitude of this voltage, it may or may not
be possible to connect the CIO-DAS16/F directly to your signal source. We will discuss this topic further in a later
section.

3. The CIO-DAS16/F and the signal source may already have isolated grounds. This signal source may be connected

directly to the CIO-DAS16/F.

Which system do you have?

1

Perform the following test: Using a battery powered voltmeter

, measure the voltage (AC and DC) between the ground
signal at your signal source and at your PC. Place one voltmeter probe on the PC ground and the other on the signal
source ground. Measure both the AC and DC Voltages.

1

If you do not have access to a voltmeter, skip the experiment and take a look at the following three sections. You may be able to identify your system type from the

descriptions provided.

11

If both AC and DC readings are 0.00 volts, you may have a system with common grounds. However, since voltmeters
will average out high frequency signals, there is no guarantee. Please refer to the section below titled Common Grounds.

If you measure reasonably stable AC and DC voltages, your system has an offset voltage between the grounds category.
This offset is referred to as a Common Mode Voltage. Please be careful to read the following warning and then proceed
to the section describing Common Mode systems.

WARNING

If either the AC or DC voltage is greater than 10 volts, do not connect the CIO-DAS16/F to this signal
source. You are beyond the boards usable common mode range and will need to either adjust your
grounding system or add special Isolation signal conditioning to take useful measurements. A ground
offset voltage of more than 30 volts will likely damage the CIO-DAS16/F board and possibly your
computer. Note that an offset voltage much greater than 24 volts will not only damage your electronics,
but it may also be hazardous to your health. In this case you will need to either reconfigure your system

to reduce the ground differentials, or install special electrical isolation signal conditioning.

If you cannot obtain a reasonably stable DC voltage measurement between the grounds, or the voltage drifts around
considerably, the two grounds are most likely isolated. The easiest way to check for isolation is to change your voltmeter
to it’s ohm scale and measure the resistance between the two grounds. It is recommended that you turn both systems off
prior to taking this resistance measurement. If the measured resistance is more than 100 Kohm, it’s a fairly safe bet that
your system has electrically isolated grounds.

Systems with Common Grounds

In the simplest (but perhaps least likely) case, your signal source will have the same ground as the CIO-DAS16/F. This
would typically occur when providing power or excitation to your signal source directly from the CIO-DAS16/F. There
may be other common ground configurations, but it is important to note that any voltage between the CIO-DAS16/F
ground and your signal ground is a potential error voltage if you set up your system based on a common ground
assumption.

As a safe rule of thumb, if your signal source or sensor is not connected directly to an LLGND pin on your
CIO-DAS16/F, it’s best to assume that you do not have a common ground even if your voltmeter measured 0.0 Volts.
Configure your system as if there is ground offset voltage between the source and the CIO-DAS16/F. This is especially
true if you are using either the CIO-DAS1402/16 or the CIO-DAS1402/12 at high gains, since ground potentials in the
sub millivolt range will be large enough to cause A/D errors, yet will not likely be measured by your handheld voltmeter.

Systems with Common Mode (ground offset) Voltages

The most frequently encountered grounding scenario involves grounds that are somehow connected, but have AC and/or
DC offset voltages between the CIO-DAS16/F and signal source grounds. This offset voltage my be AC, DC or both and
may be caused by a wide array of phenomena including EMI pickup, resistive voltage drops in ground wiring and
connections, etc. Ground offset voltage is a more appropriate term to describe this type of system, but since our goal is to
keep things simple, and help you make appropriate connections, we’ll use the phrase Common Mode.

Small Common Mode Voltages

If the voltage between the signal source ground and CIO-DAS16/F ground is small, the combination of the ground
voltage and input signal will not exceed the CIO-DAS800’s +/-10V common mode range, (i.e. the voltage between
grounds, added to the maximum input voltage, stays within +/-10V), This input is compatible with the CIO-DAS16/F and
the system may be connected without additional signal conditioning. Fortunately, most systems will fall in this category
and have a small voltage differential between grounds.

Large Common Mode Voltages

If the ground differential is large enough, the CIO-DAS800’s +/- 10V common mode range will be exceeded (i.e. the
voltage between CIO-DAS16/F and signal source grounds, added to the maximum input voltage you’re trying to measure
exceeds +/-10V). In this case the CIO-DAS16/F cannot be directly connected to the signal source. You will need to

12

change your system grounding configuration or add isolation signal conditioning. (Please look at our ISO-RACK and
ISO-5B-series products to add electrical isolation, or give our technical support group a call to discuss other options).

NOTE

Relying on the earth prong of a 120VAC for signal ground connections is not advised.. Different ground
plugs may have large and potentially even dangerous voltage differentials. Remember that the ground
pins on 120VAC outlets on different sides of the room may only be connected in the basement. This
leaves the possibility that the “ground” pins may have a significant voltage differential (especially if the
two 120 VAC outlets happen to be on different phases!)

CIO-DAS16/F and Signal Source Having Isolated Grounds

Some signal sources will already be electrically isolated from the CIO-DAS16/F. The diagram below shows a typical
isolated ground system. These signal sources are often battery powered, or are fairly expensive pieces of equipment
(since isolation is not an inexpensive proposition), isolated ground systems provide excellent performance, but require
some extra effort during connections to assure optimum performance is obtained. Please refer to the following sections
for further details

3.3 WIRING CONFIGURATIONS

Combining all the grounding and input type possibilities provides us with the following potential connection
configurations. The combinations along with our recommendations on usage are shown in Table 3-1 below.

GROUND

CATEGORY

Common Mode

Voltage < +/-10V

Common Mode

Voltage < +/-10V

Common Mode

Voltage > +/- 10V

Common Mode

Voltage > +/-10V

Already Isolated

Grounds

Table 3-1. Input Type Recommendations

INPUT

OUR VIEW

CONFIGURATION

RecommendedSingle-Ended InputsCommon Ground

AcceptableDifferential InputsCommon Ground

Not RecommendedSingle-Ended Inputs

RecommendedDifferential Inputs

Unacceptable without

Single-Ended Inputs

adding Isolation

Unacceptable without

Differential Inputs

adding Isolation

AcceptableSingle-ended InputsAlready Isolated Grounds

RecommendedDifferential Inputs

The following sections depicts recommended input wiring schemes for each of the eight possible input
configuration/grounding combinations.

13

3.3.1 Common Ground / Single-Ended Inputs

g

g

g

Single-ended is the recommended configuration for common ground connections. However, if some of your inputs are
common ground and some are not, we recommend you use the differential mode. There is no performance penalty (other
than loss of channels) for using a differential input to measure a common ground signal source. However the reverse is
not true. Figure 3-4 below shows a recommended connection diagram for a common ground / single-ended input system

NOTE: For simplicity, the input multiplexer is not shown in the following diagrams.

Signal

S our c e w ith

C om m on Gn d

Optional wire
since signal source
and A/D board share
common ground





I/O

Connector

CH IN

LL GND

Signal source and A/D board
sharin

common ground connected

to s in

le- en d e d in p u t.

+

Inp u t
Amp

-

A/D Board

To A / D

.

y

Figure 3-4.

Single-Ended

Input

3.3.2 Common Ground / Differential Inputs

The use of differential inputs to monitor a signal source with a common ground is a acceptable configuration though it
requires more wiring and offers fewer channels than selecting a single-ended configuration. Figure 3-5 shows the
recommended connections in this configuration.

Signal

So ur ce w ith

Co mm o n G n d

Optiona l w ire
since signal source
and A/D board sha re
common ground

Figure 3-5. Common Ground - Differential Input





Required conn ection
of LL GND to CH Low

I/O

Connector

CH High

CH Low

LL GND

Signal source and A/D board
sharin

com m on ground connected

to differential input.

+

Input
Amp

-

A/D Board

To A /D

14

3.3.3 Common Mode Voltage < +/-10V/Single-Ended Inputs

g

g

g

g

g

g

g

g

g

This is not a recommended configuration. In fact, the phrase common mode has no meaning in a single-ended system and
this case would be better described as a system with offset grounds. Anyway, you are welcome to try this configuration,
no system damage should occur and depending on the overall accuracy you require, you may receive acceptable results.

Signal Source

w ith Com m o n

Mo d e Vol ta g e

The voltage differential
between these grounds,
added to the maximum
input signal must stay
within +/-10 V

Signal source and A/D board
with common m ode volta
connected to a differential input.

GND





I/O

Connector

CH Hi

CH Low

LL GND

h

+

Inp ut

Amp

-

A/D Board

To A / D

e

Figure 3-6.

Common Mode Voltage < +/-10V/Single-Ended Inputs

3.3.4 Common Mode Voltage < +/-10V/Differential Inputs

Systems with varying ground potentials should always be monitored in the differential mode. Care is required to assure
that the sum of the input signal and the ground differential (referred to as the common mode voltage) does not exceed the
common mode range of the A/D board (+/-10V on the CIO-DAS16/F). Figure 3-7 shows recommended connections in
this configuration.

Iso la tio n

Barrier

arge common

L

mode voltage

between signal

source & A/D board

When the voltage difference
between si
A/D board
enou
common mode ran
exceeded, isolated si
conditionin

System with a Large Common Mode Voltage,





GND

nal source and
round is large

h so the A/D board’s

e is

nal

must be added.

Connected to a Sin

CH IN

LL GND

I/O

Conn ector

le-Ended Input

+

Input
Amp

-

A/D Board

To A /D

Figure 3-7. Common Mode Voltage < +/-10V/Differential Inputs

15

3.3.5 Common Mode Voltage > +/-10V

g

g

g

g

g

g

g

The CIO-DAS16/F will not directly monitor signals with common mode voltages greater than +/-10V. You will either
need to alter the system ground configuration to reduce the overall common mode voltage, or add isolated signal
conditioning between the source and your board (Figure 3-8).

Isolation

Barrier

arge comm on

L

mode voltage

between signa l
source & A/D bo a rd

GND





10 K

CH Hi

CH Low

LL GND

h

+

Inpu t

Amp

To A / D

-

When the voltage difference

nal source and

between si

round is large

A/D board
enou

h so the A/D board’s
comm on m ode ran
exceeded, isolated si
conditionin

e is

nal

must be added.

10K is a recommended value. You may short LL GND to CH Low
instead, but this will reduce your system’s noise immunity.

I/O

Connector

A/D Board

System with a Large Com m on M ode Voltage,

Connected to a Differential Input

Figure 3-8. Common Mode Voltage > +/-10V - Differential Input

3.3.6 Isolated Grounds / Single-Ended Inputs

Single-ended inputs can be used to monitor isolated inputs, though the use of the differential mode will increase you
system’s noise immunity. Figure 3-9 shows the recommended connections is this configuration.

Isolated

signal

s o urc e





CH IN

LL GND

I/O

Connector

+

-

Inpu t

Amp

To A /D

A/D Board

Iso lat e d S ignal Source

Connected to a Single-Ended Input

Figure 3-9. Isolated Grounds / Single-Ended Inputs

16

3.3.7 Isolated Grounds / Differential Inputs

g

Optimum performance with isolated signal sources is assured with the use of the differential input setting. Figure 3-10 below shows the
recommend connections is this configuration..

Signal Source

an d A/D Bo a rd

A lread y I s o la te d .

GND





10 K

CH High

CH Low

LL GND

+

-

Input
Amp

To A /D

These

rounds are

electrically isolated.

Figure 3-10. Isolated Grounds/Differential Inputs

I/O

Connector

10K is a recommended value. You m ay short LL GND to CH Low
instead, but this will reduce your system’s noise imm unity.

Already isolated signal source

and A/D board connected to

a differential input.

A/D Board

17

4 CIO-DAS16 CONTROL & DATA REGISTERS

4.1 INTRODUCTION

The CIO-DAS16 is controlled and monitored by writing to and reading from 20 consecutive 8-bit I/O addresses
(registers). The first address, or BASE ADDRESS, is determined by setting a bank of switches on the board.

Register manipulation is best done by experienced programmers since most of the CIO-DAS16 functions are
implemented in easy-to-use Universal Library™ routines.

The register descriptions all follow the format:

01234567

A/D11A/D10A/D9

LSB

The numbers along the top row are the bit positions within the 8-bit byte and the numbers and symbols in the bottom row
are the functions associated with that bit.

To write to or read from a register in decimal or HEX, the following weights apply (Table 4-1):

CH1CH2CH4CH8A/D12

Table 4-1. Register Bit Weights

HEX VALUEDECIMAL VALUEBIT POSITION

110
221
442

883
10164
20325
40646
801287

To write control or data to a register, the individual bits must be set to 0 or 1 then combined to form a byte.
The method of programming required to set/read bits from bytes is beyond the scope of this manual.
In summary form, the registers and their function are listed on Table 4-2. Within each register are eight bits which may

constitute a byte of data or eight individual bit read/write functions.

18

Table 4-2. Register Summary

WRITE FUNCTIONREAD FUNCTIONADDRESS

Start A/D FunctionA/D Bits 9 - 12 (LSB) & Channel #BASE
NoneA/D Bits 1 (MSB) - 8BASE + 1
Channel MUX SetChannel MUX ReadBASE + 2
Digital 4 Bit OutputDigital 4 Bit InputBASE + 3
D/A 0 Bits 9-12 (LSB)NoneBASE + 4
D/A 0 Bits 1(MSB)-8NoneBASE + 5
D/A 1 Bits 9-12 (LSB)NoneBASE + 6
D/A 1 Bits 1(MSB) - 8NoneBASE + 7
Interrupt ResetStatus EOC, UNI/BIP etc.BASE + 8
Set DMA, INT etcDMA, Interrupt & Trigger ControlBASE + 9
NonePacer clock control register.BASE + 10

Reserved for future use.BASE + 11

Counter 0 DataCounter 0 DataBASE + 12
CTR 1 Data - A/D Pacer CTR 1 Data - A/D Pacer ClockBASE + 13
CTR 2 Data - A/D Pacer CTR 2 Data - A/D Pacer ClockBASE + 14
Pacer Clock Control (8254)None. No read back on 8254BASE + 15
Port A OutputPort A Input of 8255BASE + 16
Port B OutputPort B Input BASE + 17
Port C OutputPort C InputBASE + 18
Configure 8255None - No read back on 8255BASE + 19

4.2 A/D DATA & CHANNEL REGISTERS

BASE ADDRESS

01234567

A/D11A/D10A/D9

LSB

A read/write register.

READ:
On read, it contains two types of data. The least significant four digits of the analog input data and the channel number

which the current data was taken from.
These four bits of analog input data must be combined with the eight bits of analog input data in BASE + 1, forming a

complete 12-bit number. The data is in the format 0 = minus full scale. 4095 = +FS.
The channel number is binary-coded. The weights are shown in Table 4-1. For example, if the current channel were five,

then bits CH4 and CH1 would be high and CH8 and CH2 would be low.

WRITE:

CH1CH2CH4CH8A/D12

Writing any data to the register causes an immediate A/D conversion.

19

BASE ADDRESS +1

01234567

A/D8A/D7A/D6A/D5A/D4A/D3A/D 2A/D1

MSB

A Read-only register.
On read, the most significant A/D byte is read.

4.3 CHANNEL MUX SCAN LIMITS REGISTER

BASE ADDRESS +2

01234567

CH L1CH L2CH L4CH L8CH H1CH H2CH H4CH H8

A read and write register.
READ:
The current channel scan limits are read as one byte. The high channel number scan limit is in the most significant four

bits. The low channel scan limit is in the least significant four bits.

WRITE:
The channel scan limits desired are written as one byte. The high channel number scan limit is in the most significant

four bits. The low channel scan limit is in the least significant four bits.
That is one way of looking at this register, and probably the most sensible way. In fact, the bits 3-0 contain the starting

channel number and bits 7-4 contain the ending channel number. If you wanted to scan channels 1, 2, 3 in that order, you
could do so by placing the 3 in bits 7-4 and the 1 in bits 3-0.

NOTE

Every write to this register sets the current A/D channel MUX setting to the number in bits 0-3. See
BASE + 8.

4.4 FOUR-BIT DIGITAL I/O REGISTERS

BASE ADDRESS +3

01234567

D12,

D130001

CTR 0
GATE

DI0,

TRIGDI1

20

READ:
The signals present at the inputs are read as one byte, the digital input data being contained in the four least significant

bits. The pins 25 (digital input 0) and 24 (digital input 2) digital inputs have two functions each.
The TRIG function of digital input 0 may be used to hold off the first sample of an A/D set by holding it low (0V) until

you are ready to take samples, which are then paced by the 82C54. It can also be used as the source of an external start
conversion pulse, synchronizing A/D conversions to some external event.

BASE ADDRESS +3

01234567

DO0DO1DO2DO3XXXX

WRITE:
The upper four bits are ignored. The lower four bits are latched TTL outputs. Once written, the state of the inputs cannot

be read back because a read back would read the separate digital input lines (see above).

NOTE

The digital lines 0 to 4, pins 3, 4, 5, 6, 22, 23, 24, and 25 of the analog connector should not be used as
ON/OFF Digital I/O. Read on.

The digital inputs have multiple functions as described above. The digital outputs are also used by the CIO-EXP family
of multiplexer expansion boards. The original DAS-16 design had insufficient number of digital I/O, so we added a
PIO-12 compatible 24-line 8255 to the design. We suggest that you use these lines for ON/OFF digital functions, keeping
the 4-bit ports on the analog connector free.

4.5 D/A REGISTERS

D/A 0 REGISTERS

BASE ADDRESS +4

01234567

D/A11D/A10D/A9

LSB

BASE ADDRESS+5

XXXXD/A12

01234567

D/A8D/A7D/A6D/A5D/A4D/A3D/A2D/A1

21

D/A 1 REGISTERS

BASE ADDRESS +6

01234567

XXXXD/A12D/A11D/A10D/A9

BASE ADDRESS +7

01234567

D/A8D/A7D/A6D/A5D/A4D/A3D/A2D/A1

WRITE ONLY:
Each 12-bit D/A output line has two registers. The first contains the four least significant bits of the data and four bits

that don't matter. The second register contains the eight most significant bits of the data.
The D/A will be updated when the eight most significant bits (upper register) are written. In this way, the lower four bits

can be written with no effect on the D/A output until the remainder of the data is written to the upper eight bits.

4.6 STATUS REGISTER

BASE ADDRESS + 8

01234567

CH1CH2CH4CH8INTMUXU/BEOC

A read mostly, one-function-write register.
READ:
EOC = 1, the A/D converter is busy. EOC = 0, it is free.
U/B = 1, the amplifier is in Unipolar mode. U/B = 0, is bipolar.
MUX = 1, Channels are configured 16 single ended. MUX = 0, 8 differential.
INT = 1, an external pulse has been received. INT = 0, the flip-flop is ready to receive a pulse..
There is a flip-flop on the TRIGGER input (pin 25) which will latch a pulse as short as 200 ns. After being triggered, this

flip-flop must be reset by a write to this register. Your interrupt service routine must do this before another interrupt
trigger can be received.

CH8, CH4, CH2 and CH1 make up a binary number between 0 and 15 indicating the channel number that the MUX is
currently set to. It is valid only when EOC = 0. The channel MUX increments shortly after EOC = 1 so may be in a state
of transition when EOC = 1. The binary weight of each bit is shown in Table 4-1.

WRITE:
A write of any data to this register resets the flip-flop on the pin 25 input and sets the INT bit to 0.

22

4.7 DMA, INTERRUPT & TRIGGER CONTROL

BASE ADDRESS + 9

01234567

TS0TS1DMADon’t CareIR1IR2IR4INTE

A read and write register.

READ OR WRITE:
INTE = 1, Interrupts are enabled. An interrupt generated will be placed on the PC bus interrupt level selected by IR4,

IR2, and IR1. When INTE = 0, interrupts are disabled.
IR4, IR2, and IR1 are bits in a binary number between 0 and 7 which map interrupts onto the PC bus interrupt levels 2 to

7. Interrupts 0 and 1 can not be asserted by the CIO-DAS16.

When DMA = 1, DMA transfers are enabled. When DMA = 0, DMA transfers are disabled. Note that a DMA request
can be asserted only on the DMA request level selected by the DMA switch on the board. Before this bit is set to 1, the
PC's 8237 (or appropriate) DMA controller chip must be set up.

TS1 & TS0 control the source of the A/D start conversion trigger according to Table 4-3 below.

Table 4-3. Start Conversion Trigger Source - Control Bit Coding

TS0TS1

Action
Software triggered A/D onlyX0

Start on rising TRIGGER (Digital input 0, Pin 25)01
Start on Pacer Clock Pulse (CTR 2 OUT, no external access)11

4.8 PACER CLOCK CONTROL REGISTER

BASE ADDRESS +10

01234567

TRIG0CTR0XXXXXX

Write only
When CTR0 = 1, an on-board 100 KHz clock signal i s ANDed with the COUNTER 0 CLOCK INPUT (pin 21) . A high

on pin 21 will allow pulses from the on-board source into the 8254 Counter 0 input.
When CTR0 = 0, the input to 82C54 Counter 0 is entirely dependent on pulses at pin 21, COUNTER 0 CLOCK INPUT.

TRIG0 = 1. The TRIGGER input at pin 25 is ANDed with TRIG0 which controls gating of the on-board pacer clock
(82C54). When TRIG0 = 1, the on-board pacer clock can be gated off (disabled) by pulling pin 25 low. The input at pin
25 is pulled up and will always be high unless pulled low externally.

23

When TRIG0 = 0, the external trigger at pin 25 has no effect on the GATEs of counter 1 and 2.
See Figure 4-1 for a block diagram of the Pacer Clock logic.

Figure 4-1. Pacer Clock and Control Logic

+5V

10K

COUNTER 0

COUNTER 1

COUNTER 2

A/D PACER

OUT

OUT

OUT

24

CTR 0 GATE

CTR 0 CLOCK IN

21

2

CTR 0 OUT

20

CTR 2 OUT

TRIGGER

25

CONTROL REGISTER
BASE + 10

TRIG0

CTR0

10 MHz

1 /10

1 /10

10 MHz

1MHz

+5V

10K

GATE

GATE

GATE

+5V

10K

4.9 BASE + 11 - RESERVED REGISTER

BASE ADDRESS + 11

This address is reserved for use as a programmable gain register in other DAS16 family boards.

4.10 PACER CLOCK DATA & CONTROL REGISTERS

8254 COUNTER 0 DATA
BASE ADDRESS +12

8254 COUNTER 1 DATA
BASE ADDRESS +13

24

01234567

D0D1D2D3D4D5D6D7

01234567

D0D1D2D3D4D5D6D7

82C54 COUNTER 2 DATA
BASE ADDRESS +14

01234567

D0D1D2D3D4D5D6D7

The three 82C54 counter/timer data registers may be written to and read from. Because each counter can count to
65,535, loading or reading the counter data must be a multi-step process. The operation of the 82C54 is explained in the
Intel 82C54 data sheet.

82C54 COUNTER CONTROL

BASE ADDRESS +15

01234567

D0D1D2D3D4D5D6D7

This register controls the operation and loading/reading of the counters. The configuration of the 82C54 codes which
control the 82C54 chip is explained in the Intel 82C54 data sheet.

4.11 24-LINE DIGITAL I/O REGISTERS

PORT A DATA
BASE ADDRESS +16

01234567

A0A1A2A3A4A5A6A7

PORT B DATA
BASE ADDRESS +17

01234567

B0B1B2B3B4B5B6B7

Ports A and B may be programmed as input or output. Each is written to and read from in bytes, although for control and
monitoring purposes the individual bits are used.

Bit set/reset and bit read functions require that unwanted bits be masked out of reads and ORed into writes.

PORT C DATA
BASE ADDRESS +18

01234567

C0C1C2C3C4C5C6C7

CL0CL1CL2CL3CH0CH1CH2CH3

25

Port C may be used as one 8-bit port of either input or output, or it may be split into two 4-bit ports which can be
independently input or output. The notation for the upper 4-bit port is CH3 to CH0, and for the lower, CL3 to CL0.

Although it may be split, every read and write to port C carries eight bits of data so unwanted information must be
ANDed out of reads, and writes must be ORed with the current status of the other port.

OUTPUT PORTS:
In 8255 mode 0 configuration, ports configured for output, hold the output data written to them. The output byte may be

read back by reading a port configured for output.

INPUT PORTS:
In 8255 mode 0 configuration, ports configured for input, read the state of the input lines at the moment, transitions are

not latched.

8255 CONTROL REGISTER

BASE ADDRESS +19

01234567

CLBM1CHAM2M3MS

Group BGroup A

The 8255 can be programmed to operate in Input/Output (mode 0), Strobed Input/Output (mode 1) or Bi-Directional Bus
(mode 2).

When the PC is powered up or RESET, the 8255 is reset. This places all 24 lines in Input mode and no further
programming is needed to use the 24 lines as TTL inputs.

To program the 8255 for other modes, the following control code byte must be assembled into an 8-bit byte.

GROUP A FUNCTIONM2M3

Input/OutputMode 010
Strobed Input/OutputMode 110
Bi-Directional BusMode 2X1

MS = Mode Set. 1 = mode set active. M1 = 0 is mode 0 for group B. Input / Output. M1 = 1 is mode 1 for group B.
Strobed Input / Output

CHCLBA

INDEPENDENT

FUNCTION

Input1111

Output0000

The Ports A, B, C High, and C Low may be independently programmed for input or output.

26

The two groups of ports, group A and group B, may be independently programmed in one of several modes. The most
commonly used mode is mode 0, input / output mode. The codes for programming the 82C55 in this mode are shown in
Table 4-4. D7 is always 1 and D6, D5 & D2 are always 0.

Table 4- 4. Programming Codes for 82C55 in Mode 0, Input/Output Mode

CLBCHADECHEXD0D1D3D4

OUTOUTOUTOUT128800000

INOUTOUTOUT129811000

OUTINOUTOUT130820100

ININOUTOUT131831100

OUTOUTINOUT136880010

INOUTINOUT137891010

OUTININOUT1388A0110

INININOUT1398B1110

OUTOUTOUT IN144900001

INOUTOUTIN145911001

OUTINOUTIN146920101

ININOUTIN147931101

OUTOUTININ152980011

INOUTININ153991011

OUTINININ1549A0111

ININININ1559B1111

27

5 SPECIFICATIONS

Power consumption

+5V: 780 mA typical, 975 mA max
+12V: 20 mA typical, 25 mA max

-12V: 27 mA typical, 34 mA max

Analog input section

A/D converter type

CIO-DAS16 AD674

CIO-DAS16/F AD774
Resolution 12 bits
Number of channels 8 differential or 16 single-ended, switch selectable
Input Ranges ±10V, ±5V, ±2.5V, ±1V, ±0.5V, 0 to 10V, 0 to 5V, 0 to 2V, 0 to 1V and

user settable through resistor selection
Polarity Unipolar/Bipolar, switch selectable
A/D pacing Programmable: internal counter or external source (Dig In 0 / Trigger, rising

edge) or software polled
A/D Trigger sources External polled gate trigger (Dig In 0 / Trigger, active high)
A/D Triggering Modes

Digital: Gated pacer, software polled. (Gate must be disabled by software after

trigger event.)

Data transfer Interrupt, DMA or software polled
DMA Channel 1 or 3, switch selectable
A/D conversion time

CIO-DAS16 15 µs
CIO-DAS16/F 8.5 µs

Throughput

CIO-DAS16 50 kHz min
CIO-DAS16/F 100 kHz min

Accuracy 0.01% of reading ±1 LSB
Differential Linearity error ±1 LSB
Integral Linearity error ±1 LSB
No missing codes guaranteed 12 bits

Gain drift (A/D specs) ±25 ppm/°C
Zero drift (A/D specs) ±10µV/°C
Common Mode Range ±10V
CMRR @ 60Hz 72 dB
Input leakage current (@25 Deg C) 25 µA
Input impedance 50 Meg Ohms min
Absolute maximum input voltage ±35V

28

Analog Output

D/A converter type MX7548
Resolution 12 bits
Number of channels 2
Output Ranges 0 to 5V using on-board reference, ±10V range using external reference

(Vout max = −1 * VRef)

Offset error Adjustable to 0 with potentiometer
Gain error Adjustable to 0 with potentiometer
Differential non linearity ±1LSB max
Integral non linearity ±1LSB max
Monotonicity ±0.5 LSB
D/A Gain drift ±5 ppm/°C max

D/A pacing Software paced
D/A trigger modes Software
Data transfer Software
Throughput System dependent
Settling time (output current to ±½LSB)1µs max
Slew Rate (OP07) 0.3V/µs

Current Drive ±5 mA
Output short-circuit duration 25 mA indefinite
Output coupling DC
Output impedance 0.1 Ohms max

Miscellaneous Double buffered output latches

Digital Input / Output

Digital Type (main connector)

Output: 74LS374

Input: 74S244
Configuration 4 bits as input, 4 bits as output
Number of channels 8
Output High 2.4 volts min @ −2.6 mA
Output Low 0.5 volts max @ 24 mA
Input High 2.0 volts min, 7 volts absolute max
Input Low 0.8 volts max, −0.5 volts absolute min

Digital Type (Digital I/O connector) 82C55

Configuration 2 banks of 8, 2 banks of 4, programmable by bank as input or output
Number of channels 24 I/O
Output High 3.0 volts min @ −2.5 mA
Output Low 0.4 volts max @ 2.5 mA
Input High 2.0 volts min, 5.5 volts absolute max
Input Low 0.8 volts max, −0.5 volts absolute min

Interrupts 2 - 7, software selectable
Interrupt enable Programmable
Interrupt sources A/D End-of-conversion, DMA terminal count

29

Counter section

Counter type 82C54
Configuration 82C54 device. 3 down-counters, 16 bits each

Counter 0 - Independent user counter

Source: Internal 100 kHz or external (CTR 0 Clock In), software selectable
Gate: External (Dig In 2 / CTR 0 Gate), software enabled
Output: Available at user connector (CTR 0 Out)

Counter 1 - ADC Pacer Lower Divider

Source: 1 or 10 MHz oscillator, jumper selectable
Gate: Tied to Counter 2 gate, programmable source: external (Dig In 0 /

Trigger) or internal

Output: Chained to Counter 2 Clock.

Counter 2 - ADC Pacer Upper Divider

Source: Counter 1 Output.
Gate: Tied to Counter 1 gate, programmable source (external or internal).

Output: ADC start convert, available at user connector (CTR 2 Out)
Clock input frequency 10 MHz max
High pulse width (clock input) 30 ns min
Low pulse width (clock input) 50 ns min
Gate width high 50 ns min
Gate width low 50 ns min
Input low voltage 0.8V max
Input high voltage 2.0V min
Output low voltage 0.4V max
Output high voltage 3.0V min

Environmental

Operating temperature range 0 to 50°C
Storage temperature range -20 to 70°C
Humidity 0 to 95% non-condensing

30

EC Declaration of Conformity

We, Measurement Computing Corp., declare under sole responsibility that the product:

CIO-DAS16/F

DescriptionPart Number

to which this declaration relates, meets the essential requirements, is in conformity with, and CE marking has been applied according to
the relevant EC Directives listed below using the relevant section of the following EC standards and other normative documents:

EU EMC Directive 89/336/EEC

EU 55022 Class B

EN 50082-1

IEC 801-2

IEC 801-3

IEC 801-4

Carl Haapaoja, Director of Quality Assurance

: Electrostatic discharge requirements for industrial process measurement and control equipment.

: Radiated electromagnetic field requirements for industrial process measurements and control equipment.

: Electrically fast transients for industrial process measurement and control equipment.

: Limits and methods of measurements of radio interference characteristics of information technology equipment.

: EC generic immunity requirements.

: Essential requirements relating to electromagnetic compatibility.

Measurement Computing Corporation

16 Commerce Boulevard,

Middleboro, Massachusetts 02346

[phone]

Fax: [phone]

E-mail: [e-mail]

www. measurementcomputing.com