CIO-DI48,
CIO-DI96,
CIO-DI192
User’s Manual

Revision 3A
October, 2000

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photocopying, recording, or otherwise without the prior written permission of Measurement Computing
Corporation.
NoticeMeasurement Computing Corporation does not authorize any Measurement Computing Corporation product for
use in life support systems and/or devices without prior written consent from Measurement Computing
Corporation. Life support devices/systems are devices or systems that, a) are intended for surgical implantation
into the body, or b) support or sustain life and whose failure to perform can be reasonably expected to result ininjury. Measurement Computing Corporation products are not designed with the components required, and are
not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

Table of Contents
1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 SOFTWARE INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 1
3.0 HARDWARE SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.1 BASE ADDRESS SELECTION . . . . . . . . . . . . . . . . . . . . . . . . 2
4.0 HARDWARE INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . 5
4.1 INSTALLING THE BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2 CABLING TO THE CONNECTOR(S) . . . . . . . . . . . . . . . . . . . 5
4.3 DIGITAL SIGNAL CHARACTERISTICS . . . . . . . . . . . . . . . . . 5
4.4 CONNECTOR PIN-OUT DIAGRAMS . . . . . . . . . . . . . . . . . . . 6
5.0 DATA REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 CIO-DI48 REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3 CIO-DI96 REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.4 CIO-DI192 REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.0 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.0 INTERFACING TECHNIQUES . . . . . . . . . . . . . . . . . . . . . . 15
7.1 UNCONNECTED INPUTS FLOAT . . . . . . . . . . . . . . . . . . . . 15
7.2 TTL TO SOLID STATE RELAYS . . . . . . . . . . . . . . . . . . . . . 16
7.3 VOLTAGE DIVIDERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.4 LOW-PASS FILTERS DE-BOUNCE INPUTS . . . . . . . . . . . . . 17

This page is intentionally blank.

1.0 INTRODUCTION
The CIO-DI48, 96 and 192 are designed to have the best quality and lowest cost of
any digital input board.
Throughout this m anual the model number CIO-DI## is use d when the information
applies to the CIO-DI48, CIO-DI96 and CIO-DI192 inclusive. Exclusive information
for a particular version will be identified.
CIO-DI48 is a dedicated 48-line digital input board built up of six, eight-input logic
chips. There are no control registers. The input pins present a single LSTTL load.
Similarly, the 96-line and 192-line versions use 12 or 24 ei ght-input logic chips
respectively.
The CIO-DI## also conforms to the connector pin specification of all the CIO-DIO
family of digital boards, so m ay be used in place of one another without changing
cabling or connectors.
All these products are supported by Universal Library programming library.
A group of application notes at the end of this manual describes electrical interfacing
subjects that may be useful for digital I/O applications.

2.0 SOFTWARE INSTALLATION
In order to easily test your installation, it is recommended that you install InstaCal, theinstallation, calibration and test utility that was supplied with your board. Refer to the
Extended Software Installation Manual for information on the initial setup, loading,and installation of InstaCal and optional Universal Library software.
InstaCal will guide you through hardware settings and allow you to easily test for
conflicts. If you decide not to u se Instacal to assist board configuration, details areprovided in the following section.

1

3.0 HARDWARE SETUP

3.1 BASE ADDRESS SELECTION
The CIO-DI## employs the PC bus for power, communications and data transfer. As
such it draws power from the PC, monitors the address lines and control signals andresponds to it's I/O address, and it receives and places data on the 8 data lines.
The BASE address is the most important user-selectable feature of the CIO-DI##.
The base address, an d offsets from it, are the locations that PC software reads input
data from.
Base address dip switches are used for setting the base address. Each switch position
corresponds to one of the PC bus address lines. Placing a switch down puts it in theactive position.
A complete address is constructed by adding the HEX o r decimal number whichcorresponds to all the address bits the CIO-DI## has been instructed to respond to.
For example shown in Figure 3-1, switches 9 and 8 are DOWN, al l others UP.
Address 9 = 200h (512D) and address 8 = 100h
(256D), When added together they equal 300h (768D).
NOTE
Disregard the numbers printed on the switch; refer only to thenumbers printed in white on the board!
In Figure 3-1, note that the number of switches varies with the board version.
Certain addresses are used by the PC, others are free and may be used by the
CIO-DI## and other expansion boards. We recommend trying the factory default
address 300h (768D) first.

2

I

I

I
Figure 3-1. Base Address Switches

3

HEX
RANGE
000-00F
020-021040-043060-063060-064070-071080-08F
0A0-0A1
0A0-0AF
0C0-0DF
0F0-0FF
1F0-1FF
200-20F
210-21F
238-23B
23C-23F
270-27F
2B0-2BF

Table 2-1. PC I/O Addresses
FUNCTION
HEX
RANGE
8237 DMA #1
2C0-2CF8259 PIC #1
2D0-2DF
8253 TIMER
2E0-2E78255 PPI (XT)
2E8-2EF
8742 CONTROLLER (AT)
2F8-2FFCMOS RAM & NMI MASK (AT)
300-30FDMA PAGE REGISTERS
310-31F
8259 PIC #2 (AT)320-32FNMI MASK (XT)378-37F
8237 #2 (AT)380-38F
80287 NUMERIC CO-P (AT)3A0-3AF
HARD DISK (AT)
3B0-3BBGAME CONTROL
3BC-3BF
EXPANSION UNIT (XT)
3C0-3CFBUS MOUSE
3D0-3DFALT BUS MOUSE
3E8-3EFPARALLEL PRINTER
3F0-3F7EGA
3F8-3FFFUNCTION
EGA
EGA
GPIB (AT)SERIAL PORTSERIAL PORTPROTOTYPE CARD
PROTOTYPE CARD
HARD DISK (XT)
PARALLEL PRINTER
SDLC
SDLC
MDA
PARALLEL PRINTEREGACGASERIAL PORTFLOPPY DISKSERIAL PORTThe BASE switch can be set for address in the range of 000-3F8 so it should not be
hard to find a free address area f or you CIO-DI##. Once again, if you are not using
IBM prototyping cards or s ome other board which occupies these addresses, then300-31F HEX are free to use.
Addresses not specifically listed, such as 390-39F, are not reserved and may beavailable. Check your computer for other boards which may use I/O addresses.

44.0 HARDWARE INSTALLATION

4.1 INSTALLING THE BOARD
1.
2.
3.
4.

Turn the power off.
Remove the cover of your computer. Please be careful not to dislodge any of
the cables installed on the boards in your computer as you slide the cover off.
Locate an empty expansion slot in your computer.
Push the b oard firmly down into the exp ansion bus connector. If it is no t
seated fully it may fail to work and could short circuit the PC bus power ontoa PC bus signal. This could damage the motherboard in your PC as well as
the CIO-DI##.

4.2 CABLING TO THE CONNECTOR(S)The input connector(s) are accessible through the PC/AT expansion bracket. The
connector is a stan dard 50-pin header connector. Cables with mating connectors(C50FF-#) can be purchased from Measurement Computing Corporation.
Those familiar with the CIO-DIO series boards will find the signal levels and pin
assignments are identical with those on the CIO-DI##.

4.3 DIGITAL SIGNAL CHARACTERISTICS
Inputs are LSTTL (Low power Schotky TTL), a standard for digital signals which areeither at 0V or 5V (nominal).
Low state
High state

Near 0V
Near 5V

See the electrical sp ecification in this m anual for details regarding logic levels andmaximum voltages allowed at the inputs.
In addition to voltage and load matching, digital signals o ften need to be filtered(“de-bounced”) to remove spurious false signals from relay or switch contacts . A
description of this filtering method and other subjects on digital interfacing techniques
is in the section on Interface Electronics in this manual.
54.4 CONNECTOR PIN-OUT DIAGRAMSPORT 2

BASE + 4, +5, and +6

PORT 1

BASE + 0, +1, and +2

The CIO-DI## series boards u se 50-pin header-type connector(s) mounted on theboard that are accessible from the rear of the PC through the expansion backplate.
y The CIO-DI48 has one connector (Figure 4-2).
y The CIO-DI96 has two connectors (Figure 4-3).
y The CIO-DI192 has four connectors Figure 4-4).

Figure 4-2. CIO-DI48 Connector Pin-Out & Register Assignments
NOTE: The input signals are direct connections to a digital buffer chip.
The connector accepts female 50-pin header type connectors, such as th ose on the
C50FF-2, 2 foot cable with connectors.

6

If frequent changes to signal co nnections or signal co nditioning is required, pleaserefer to the information on the CIO-TERM100, CIO-SPADE50 and CIO-MINI50
screw terminal boards.

BASE + 4, +5, and +6

PORT 1PORT 2

BASE + 8, +9, and +10
BASE + 12, +13, and +14

PORT 3
PORT 4

BASE + 0, +1, and +2

P1

P2

Figure 4-3. CIO-DI96 Pin-outs & Register Assignments

7

PORT 7

PORT 5

PORT 3

8

PORT 1

BASE + 0, +1, and +2

PORT 2

BASE + 4, +5, and +6

P3

BASE + 12, +13, and +14 BASE + 8, +9, and +10

PORT 4

BASE + 20, +21, and +22 BASE + 16, +17, and +18

PORT 6

BASE + 28, +29, and +30 BASE + 24, +25, and +26

PORT 8
P4
P2
P1

Figure 4-4. CIO-DI192 Connector Pin-outs & Register Assignments

5.0 DATA REGISTERS

5.1 INTRODUCTION
Each CIO-DI## is composed of parallel input chips. Each inp ut buffer senses eight
input pins. The ports are arranged in sets o f three, with an intervening register that is
not used. This scheme allows compatibility with software written to control 82C55
based boards when the 82C55 is used as all inputs. (On those boards, every fourth
register is a control register.)
The first address, or BASE ADDRESS +0, is determined by setting a bank of switcheson the board.
To read data from an input register, a byte is read representing the status of up to eight
digital input lines.

95.2 CIO-DI48 REGISTERS
The CIO-DI48 uses eight registers. Their function is listed on Table 5-1.

ADDRESS
BASE + 0
BASE + 1
BASE + 2
BASE + 3
BASE + 4
BASE + 5
BASE + 6
BASE + 7

Table 5-1. CIO-DI48 Registers
READ FUNCTIONWRITE FUNCTION
Read Port 1A Data
None
Read Port 1B Data
None
Read Port 1C Data
None
None
None
Read Port 2A Data
None
Read Port 2B Data
None
Read Port 2C Data
None
None
None

PORTS 1A and 2A DATABASE ADDRESS + 0 and +4
7
6
5
A7
A6
A5

4
A4

3
A3

2
A2

1
A1

0
A0

PORTS 1B and 2B DATABASE ADDRESS + 1 and +5
7
6
5
B7
B6
B5

4
B4

3
B3

2
B2

1
B1

0
B0

PORTS 1C and 2C DATABASE ADDRESS + 2 and +6
7
6
5
C7
C6
C5

4
C4

3
C3

2
C2

1
C1

0
C0

10

5.3 CIO-DI96 REGISTERS
The CIO-DI96 has 16 registers. Their function is listed on Table 5-2.

ADDRESS
BASE + 0
BASE + 1
BASE + 2
BASE + 3
BASE + 4
BASE + 5
BASE + 6
BASE + 7
BASE + 8
BASE + 9
BASE + 10
BASE + 11
BASE + 12
BASE + 13
BASE + 14
BASE + 15

Table 5-2. CIO-DI96 Registers
READ FUNCTIONWRITE FUNCTION
Read Port 1A Data
None
Read Port 1B Data
None
Read Port 1C Data
None
None
None
Read Port 2A Data
None
Read Port 2B Data
None
Read Port 2C Data
None
None
None
Read Port 3A Data
None
Read Port 3B Data
None
Read Port 3C Data
None
None
None
Read Port 4A Data
None
Read Port 4B Data
None
Read Port 4C Data
None
None
None

PORTS 1A, 2A, 3A, and 4A DATABASE ADDRESS + 0, +4, +8, and +12
7
6
5
4
A7
A6
A5
A4

3
A3

2
A2

1
A1

0
A0

PORTS 1B, 2B, 3B, and 4B DATABASE ADDRESS + 1, +5, +9, and +13
7
6
5
4
B7
B6
B5
B4

3
B3

2
B2

1
B1

0
B0

PORTS 1C, 2C, 3C, and 4C DATABASE ADDRESS + 2, +6, +10, and +14
7
6
5
4
C7
C6
C5
C4

3
C3

2
C2

1
C1

0
C0

11

5.4 CIO-DI192 REGISTERS
The CIO-DI192 has 32 registers. Their function is listed on Table 5-3.

ADDRESS
BASE + 0
BASE + 1
BASE + 2
BASE + 3
BASE + 4
BASE + 5
BASE + 6
BASE + 7
BASE + 8
BASE + 9
BASE + 10
BASE + 11
BASE + 12
BASE + 13
BASE + 14
BASE + 15
BASE + 16
BASE + 17
BASE + 18
BASE + 19
BASE + 20
BASE + 21
BASE + 22
BASE + 23
BASE + 24
BASE + 25
BASE + 26
BASE + 27
BASE + 28
BASE + 29
BASE + 30
BASE + 31

Table 5-3. CIO-DI192 Registers
READ FUNCTIONWRITE FUNCTION
Read Port 1A Data
None
Read Port 1B Data
None
Read Port 1C Data
None
None
None
Read Port 2A Data
None
Read Port 2B Data
None
Read Port 2C Data
None
None
None
Read Port 3A Data
None
Read Port 3B Data
None
Read Port 3C Data
None
None
None
Read Port 4A Data
None
Read Port 4B Data
None
Read Port 4C Data
None
None
None
Read Port 5A Data
None
Read Port 5B Data
None
Read Port 5C Data
None
None
None
Read Port 6A Data
None
Read Port 6B Data
None
Read Port 6C Data
None
None
None
Read Port 7A Data
None
Read Port 7B Data
None
Read Port 7C Data
None
None
None
Read Port 8A Data
None
Read Port 8B Data
None
Read Port 8C Data
None
None
None

12

PORTS 1A through 8A DATABASE ADDRESS + 0, +4, +8, +12, +16, +20, +24, +28
7
6
5
4
3
2
A7
A6
A5
A4
A3
A2

1
A1

0
A0

PORTS 1B through 8B DATABASE ADDRESS + 1, +5, +9, +13, +17, +21, +25, and +29
7
6
5
4
3
2
B7
B6
B5
B4
B3
B2

1
B1

0
B0

PORTS 1C through 8C DATABASE ADDRESS + 2, +6, +10, +14, +18, +22, +26, and +30
7
6
5
4
3
2
C7
C6
C5
C4
C3
C2

1
C1

0
C0

13

6.0 SPECIFICATIONS
Typical for 25°C unless otherwise specified.

POWER CONSUMPTION+5V quiescent
CIO-DI48
CIO-DI96
CIO-DI192

300 mA typical, 390 mA max
475 mA typical, 620 mA max
630 mA typical, 820 mA max

DIGITAL INPUT / OUTPUT
Digital Type
Configuration
CIO-DI48
CIO-DI96
CIO-DI192
Number of channels
CIO-DI48
CIO-DI96
CIO-DI192
Input High
Input Low
Miscellaneous

74LS373
Input only
6 banks of 8 bits
12 banks of 8 bits
24 banks of 8 bits
48 inputs
96 inputs
192 inputs
2.0 volts min, 7 volts absolute max
0.8 volts max, −0.5 volts absolute min
Locations provided for installation ofpull-up or pull-down resistors.

ENVIRONMENTAL
Operating temperature range
Storage temperature range
Humidity

0 to 70°C−40 to 100°C
0 to 90% non-condensing

147.0 INTERFACING TECHNIQUESThis brief introduction to the electronics most often needed by digital I/O board users
covers a few basic concepts.

7.1 UNCONNECTED INPUTS FLOAT
Keep in mind that unconnected inputs float. If you are using the CIO-DI## board withunconnected inputs, ignore the data from those lines.
In other words, if you connect bit A0 and not bit A1, do not be surprised if A1 stays
low, stays high or tracks A0. It is unconnected and so unspecified. The input buffer is
not malfunctioning. In the absence of a pull-up or pull-down resistor, any input to a
CIO-DI## which is unconnected, is unspecified!
You do not have to tie input lines, and unconnected lines will not affect theperformance of connected lines. Just make sure that you mask out any unconnected
bits in software!
An alternative to masking inputs is to define the state of unused inputs by using
pull-up or pull-down resistors. T here are locations on the b oard for installation ofthese resistors marked RN1 through RN6 on the DI48, through RN12 on the DI96 andthrough RN24 of the DI192. The location associated with FIRST PORT A (the port
at Base +0) is RN1. The location for FIRST PORT B (the port at Base +1) is RN2.
FIRST PORT C (Base +2) is RN3; SECOND PORT A (Base +4) is RN4; SECONDPORT B (Base +5) is RN5; SECOND PORT C (Base +6) is RN6 and so on.
A 10Kohm, eight-resistor SIP has all its resistors connected on one end to a sin gle
common pin. The common pin is marked with a dot and is at one end of the SIP. The
other ends connect to eight in-line pins.
The SIP can be installed to pull-up or pull-down. At each location there are 10 holes
in a line. One end of the line is marked HI; the other end LO. The eight holes in the
middle are connected to the eight lines of a port, A, B, or C.
To pull-up lines, orient the SIP with the common pin (dot) in toward the HI end; topull-down, install the resistor with the common pin in the LO hole.
Carefully solder the SIP in place.
A resistor value of 10K is recommended. Use other values only if you havedetermined the necessity for doing so.
15

7.2 TTL TO SOLID STATE RELAYS
Many applications require digital monitoring of fairly high AC and DC input voltages.
These AC and high DC voltages cannot be read directly by the CIO-DI##.
Solid State Relays, such as those available from Measurement Computing Corporation
allow control and monitoring of AC and high DC voltages and provide 400V
isolation. So lid State Relays (SSRs) are the reco mmended method of interfacing to
AC and high DC signals.
The most convenient way to use solid state relay s and a CIO-DI## board is topurchase a Solid State Relay Rack. SSR Racks are available from Measurement
Computing Corporation.

7.3 VOLTAGE DIVIDERS
If you wish to measure a signal which varies over a range greater than the input range
of a digital input, a voltage divider can drop the voltage of the input signal to the level
the digital input can measure.
A voltage divider takes advantage of Ohm's law, which states,
Voltage = Current * Resistanceand Kirkoff's voltage law which states,
The sum of the voltage drops around a circuit will be equal to the voltage
drop for the entire circuit.
Implied in the above is that any variation in the voltage drop for the circuit as a wholewill have a proportional variation in all the voltage drops in the circuit.
A voltage divider takes advantage of the fact that the voltage across on e of theresistors in a ci rcuit is proportional to the voltage across the total resistance in thecircuit.
The trick to using a voltage divider is to choose two resistors with the proper
proportions relative to the full scale of the digital input and the maximum signal
voltage.

16

The process of dropping the voltage proportionally is often called attenuation. The
formula for attenuation is:

Attenuation = R1 + R2
R2

2 = 10K + 10K
10K

R1 = (A-1) * R2

The variable attenuation is the proportional
difference between the signal vo ltage max and thefull scale of the analog input.
For example, if the signal varies between 0 and 20
volts and you wish to measure that with an analog
input with a full scale range of 0 to 10 volts, theattenuation is 2:1 or just 2.
For a given attenuation, pick a handy resistor andcall it R2, the use this formula to calculate R1.

For example, if you wish to measure a digital signal that is at 0 v olts when off and 24
volts when on, you cannot connect that directly to the CIO-DI## digital inputs. The
voltage must be dropped t o 5 v olts maximum when on. T he Attenuation is 24:5 or
4.8. Use the equation above to find an appropriate R1 if R2 is 10K. Remember that a
TTL input is 'on' when the input voltage is greater than 2.5 volts.
IMPORTANT NOTE: The resistors, R1 and R2, are going todissipate all th e power in the divider circuit according to th eequation Current = Voltage/Resistance and power is current-squared times resistance (Pwatts = I2 x R) . T he higher the value ofthe resistance (R1 + R 2) the less power dissipated by the divider
circuit. Here is a simple rule:
For Attenuation of 5:1 or less, no resistor should be less than 10K.
For Attenuation of greater than 5:1, no resistor should be less than
1K.

7.4 LOW-PASS FILTERS DE-BOUNCE INPUTS
A low-pass filter can be placed on the signal wires between a signal and an A/Dboard. It attenuates frequencies higher than the cut-off frequency, preventing themfrom entering the A/D board's digital inputs.
The key parameter in a lo w-pass filter circuit is the cut- off frequency. T he cut-off
frequency is that frequency above which no variation of voltage can enter the circuit.
For example, if a low pass filter had a cut off frequency of 30 Hz, the kind of17

interference associated with line voltage (60 Hz) would be filtered out but a signal of
25 Hz would be allowed to pass.
In digital input circuits, low-pass filters are sometimes used to “de-bounce” inputs
from relay or switch contacts.
A simple low-pass filter may be constructed from one resistor (R) and one capacitor(C). The cut-off frequency is determined by the formula:Fc =1
2 *π * R * C

R=

1
2*π* C * Fc

Where

π = 3.14...
Fc = frequency in cycles per second
R = resistance in Ohms
C = capacitance in Farads

18

EC Declaration of Conformity
We, Measurement Computing Corporation, declare under sole responsibility that the
product:
CIO-DI48
CIO-DI96
CIO-D1192
Part Number

48 channel digital input board
96 channel digital input board
192 channel digital input board
Description

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: Essential requirements relating to electromagnetic
compatibility.
EU 55022 Class B: Limits and methods of measurements of radio interference
characteristics of information technology equipment.
EN 50082-1: EC generic immunity requirements.
IEC 801-2: Electrostatic discharge requirements for industrial process measurement
and control equipment.
IEC 801-3: Radiated electromagnetic field requirements for industrial process
measurements and control equipment.
IEC 801-4: Electrically fast transients for industrial process measurement and control
equipment.
Carl Haapaoja, Director of Quality Assurance

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com