Rockwell Automation 1791-I0VW User Manual

Block I/O
Cat. No. 1791IOBW and IOVW

User Manual

Important User Information

Because of the variety of uses for the products described in this
publication, those responsible for the application and use of this control
equipment must satisfy themselves that all necessary steps have been taken
to assure that each application and use meets all performance and safety
requirements, including any applicable laws, regulations, codes
and standards.

The illustrations, charts, sample programs and layout examples shown in
this guide are intended solely for example. Since there are many variables
and requirements associated with any particular installation, Allen-Bradley
does not assume responsibility or liability (to include intellectual property
liability) for actual use based upon the examples shown in this publication.

Allen-Bradley publication SGI–1.1, “Safety Guidelines For The
Application, Installation and Maintenance of Solid State Control”
(available from your local Allen-Bradley office) describes some important
differences between solid-state equipment and electromechanical devices
which should be taken into consideration when applying products such as
those described in this publication.

Reproduction of the contents of this copyrighted publication, in whole or
in part, without written permission of Allen–Bradley Company, Inc.
is prohibited.

Throughout this manual we make notes to alert you to possible injury to
people or damage to equipment under specific circumstances.

ATTENTION: Tells readers where people may be hurt if
procedures are not followed properly.

ATTENTION: Tells readers where machinery may be damaged
or economic loss can occur if procedures are not
followed properly.

Attention helps you:

Identify a hazard.
Avoid the hazard.
Recognize the consequences.

Important: We recommend you frequently backup your application
programs on appropriate storage medium to avoid possible data loss.

Table of Contents

Using This Manual P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Purpose
Audience P1
Vocabulary P1
Manual Organization P1
About

of Manual

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

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

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

Block I/O

P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introducing Block I/O 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
General Description 11
How

Objectives

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

the Block I/O Fits in a PLC System

11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13. . . . . . . . . . . . . . . . . . . .

Installing Block I/O 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Preinstallation Considerations 21
Installing
Connecting Wiring 23
Remote I/O Link Wiring 29
Extended
Compatibility of 1771 I/O Products with Extended Node Operation 211

Objectives

the Block I/O

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

Node Capability

21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

210. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.

Configuring Your Block I/O 31. . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Setting

Objectives

the Configuration Switches

31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Indicators 41
Replacing a Fuse 43
Summary 44

Objectives

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

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

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

41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Specifications A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Using This Manual

Preface

Purpose

of Manual

Audience

Vocabulary

Manual Organization

This manual shows you how to use your block I/O with an Allen–Bradley
programmable controller. It helps you install, program and troubleshoot
your module.

You must be able to program and operate an Allen–Bradley programmable
controller (PLC) to make efficient use of block I/O modules.

We assume that you know how to do this in this manual. If you do not,
refer to the appropriate PLC programming and operations manual before
you attempt to program this module.

In this manual, we refer to:

the block I/O module as the “block” or the “module”
the programmable controller as the “controller”

This manual is divided into 4 chapters. The following chart shows each
chapter with its corresponding title and brief overview of the topics
covered in that chapter.

Chapter Title Topics Covered

1 Introducing Block I/O

2 Installing Block I/O

3

4 Troubleshooting

Appendix A Specifications Specifications for the block I/O.

Configuring Your Block I/O for PLC
Family Programmable Controllers

Description of the modules, including general and
hardware features

Module power requirements, location, and wiring
information

How to set the configuration switches and address
the block I/O.

How to use the indicators to troubleshoot your block
I/O module.

P-1

Preface

Using This Manual

About

Block I/O

Related Publications

Block I/O consists of small, self–contained remote I/O devices complete
with power supply, programmable controller interface, input/output
connections and signal conditioning circuitry.

This publication covers the 1791–IOBW and –IOVW block I/O modules.
The 1791–IOBW has 32 sinking inputs and 32 sourcing outputs; the
1791–IOVW has 32 sourcing inputs and 32 sinking outputs. In all other
aspects, they are identical.

For a list of publications with information on Allen–Bradley
programmable controller products, consult our publication index (SD499).

P-2

Introducing Block I/O

Chapter

1

Chapter

Objectives

General Description

In this chapter you will learn what block I/O is, its features, and how
it functions.

Block I/O consists of small, self-contained remote I/O devices complete
with power supply, programmable controller interface, input/output
connections and signal conditioning circuitry.

The 1791-IOBW 24V dc module has 32 sink input channels, and 32 source
output channels.

The 1791-IOVW 24V dc module has 32 source input channels, and 32 sink
output channels.

Complete specifications for these modules are contained in Appendix A.

The blocks are compatible with PLC-2
programmable controllers, and the SLC 500
used with PLC-2 family programmable controllers, a sub-scanner module
is used to communicate with the blocks. When used with PLC-3 and
PLC-5 family programmable controllers, they can be connected directly to
the controller or to a scanner module. When used with SLC 500
controllers, a 1747-SN remote I/O scanner is used to communicate with the
blocks.



, PLC-3, and PLC-5 family



modular controllers. When

ATTENTION: However, when using PLC-3 programmable
controllers, you must use a 1775-S5 or -SR5 scanner module.

Do not use 1775-SR, -S4A or -S4B scanner modules.

Note: The 1791-IOBW and -IOVW block modules are not compatible

with the 1747-DSN scanner module.

Connections are made to removable terminal blocks mounted on the sides
of the block.

Figure 1.1 shows the physical features of the block I/O.

1-1

Chapter 1

Introducing Block I/O

Figure 1.1

Features of the 1791IOBW and IOVW Block I/O Modules

Major
(IOBW shown)

Rack Address
Switch

Power, Active,
Comm and Fuse
LED Indicators

Removable
Input Terminal
Blocks

RACK
ADDR

87654321

CONFIGURATION

SWITCHES

POWER
ACTIVE
COMM
FUSE

1791IOBW
64 POINT
24V DC DISTRIBUTED
I/O MODULE

CONFIGURATION SWITCHES

Configuration Switches
(on top of unit)

Input/Output

Status LED

Array

Removable

Output Terminal

Blocks

RIO Wiring Block

+24V dc Power

Termination
Resistor
Switch

10914I

Wiring Terminals - The remote I/O field wiring is made to two separate
removable 37-pin terminal blocks mounted on the sides of the module.
Terminal assignments are shown in chapter 2.

1-2

A separate nonremovable terminal block is provided for connection of the
remote I/O link and external 24V dc power supply.

Switch Assemblies - Two DIP switches are provided for setting the I/O
configuration and rack address.

The configuration switch lets you select baud rate, last state, processor
restart lockout, last rack and I/O group.

The rack address switch lets you select the system rack address for
the block.

A third switch is provided for selection of the built-in termination resistor.

Chapter 1

Introducing Block I/O

Status Indicators - Bi-color LED indicators provide power, active,
communication and fuse blown indications. An LED array provides
input/output status.

Indicator Indication

How the Block I/O Fits in a
PLC System

Power(green/wht)

Power (green/wht)

Active(green/red)

Active (green/red)

Comm(green/wht)

Comm (green/wht)

Fuse(red/wht)

Fuse (red/wht)

On (green) Customer voltage is present

Off (wht)

On (green) CPU operating correctly

Off (red)

On (green) Communication correctly established

Off (wht)

On (red) One of the fuses is open

Off (wht) Both fuses are intact

No customer voltage

CPU not running

Communication not established

The I/O status array is an 8 by 8 array of 64 LEDs capable of displaying
the status of 32 inputs and 32 outputs at any one time.

Block I/O is a complete I/O interface that includes the functionality of the
I/O rack, adapter, power supply, and I/O modules in a single unit. Simply
connect sensors and actuators to the module and use the remote I/O cable
to connect the block I/O to your programmable controller (Figure 1.6).

The 1791-IOBW block uses sinking inputs and sourcing outputs.

In sinking inputs, the dc common is bussed on the block. and the current is
sourced from the field device. The sourcing field device switches the hot
side of the power supply bus causing current to flow through the sourcing
device to the sinking input on the block. Refer to Figure 1.2.

1-3

Chapter 1

Introducing Block I/O

Figure 1.2

Input Example

Sinking

+V

dc Power
Supply

Field
Device

Field
Device

V

Block I/O

Sinking
Input

10826I

Sourcing outputs have the power bussed in the block. When the output is
on, current is supplied to the field control device, which sinks the current.
The field circuit and the equipment remain at ground potential until the
output is turned on. Refer to Figure 1.3.

Figure 1.3
Sourcing

Output Example

Block I/O

+V

Fuse

Fuse

Field
Device

Field
Device

dc Power
Supply

V

Bus

10827I

The 1791-IOVW block uses sourcing inputs and sinking outputs.

In sourcing input modules (Figure 1.4), the +V on dc circuits is bussed on
the module supplying (sourcing) the current for each input circuit. The
field device switches the circuit to the common (side of the power supply,
sinking the circuit and causing current to flow from the module’s input

1-4

Chapter 1

Introducing Block I/O

Figure 1.4

dc Power
Supply

V

Input Example

Field
Device

+V

Block

Input

I/O

10917I

Sourcing

dc Common Bus

In sinking outputs (Figure 1.5), the current flow is reversed. The dc
common is bussed on the module and the current is sourced from the field
device being actuated. When an output is turned on, the output switch in
the module sinks the circuit, causing current to flow from the +V bus
through the field device to the module.

Figure 1.5

Output Example

Sinking

Block I/O

Fuse

Fuse

Field
Device

Field
Device

Common

+V

Bus

dc Power
Supply

V

10918I

Block I/O functions exactly like any Allen-Bradley remote I/O product.
Input and output data is scanned asynchronously and transferred back and
forth between the block and the controller input and output image table.

You connect the block I/O to your remote I/O link as you would any other
device. The block looks like a 1/4 I/O rack to the processor, and uses 2
words of input image table memory and 2 words of output image table
memory. The block is addressed directly on the remote I/O link.

1-5

Chapter 1

Introducing Block I/O

Programmable Controller
or Scanner

Figure 1.6

I/O Connection in a PLC System

Block

Block I/O  each block
is 1/4 I/O rack.

Blocks are daisychained to a
programmable controller or scanner.

10915I

1-6

Installing Block I/O

Chapter

2

Chapter

Preinstallation
Considerations

Objectives

In this chapter you will learn how to mount the block, how to connect the
remote I/O link, how to connect the input and output wiring to the block,
and how to terminate the remote I/O link.

Before installation, you must determine:

the number of blocks desired
the total distance of the installation
transmission rate desired

2-1

Chapter 2

Installing Block I/O

Installing the Block I/O

Inches
(Millimeters)

0.67
(17.105)

6.54
(166.0)

Mounting dimensions for the block I/O module are shown in Figure 2.1.
Mount the blocks horizontally with a minimum of 2” between blocks. This
air gap is necessary to maintain proper cooling air flow through the block.

Figure 2.1
Mounting
IOVW)

Dimensions for the Block I/O Module (Cat. No. 1791IOBW and

6.15
(156.21)

4.8
(122.0)

87654321

CONFIGURATION

SWITCHES

RACK
ADDR

POWER
ACTIVE
COMM
FUSE

1791IOBW

64 POINT

24VDC DISTRIBUTED

I/O MODULE

CONFIGURATION SWITCHES

6.2
(157.0)

7.0
(178.0)

Dimensions:

6.15W x 7.0H x 1.72D

(156.21W x 178.0H x 43.7D)

10916I

The operating temperature in the air gap between block I/O modules must
not exceed 60

o

C (140oF). The dimensions of the air gap required are

shown in Figure 2.2.

2-2

Chapter 2

Installing Block I/O

Connecting Wiring

Figure 2.2
Clearance

2
(50.8)

Required for Block I/O Modules

2
(50.8)

2
(50.8)

Inches
(Millimeters)

2
(50.8)

10919I

Connections to the block I/O module are made to the removable terminal
blocks on each side of the module. Input connections are on the left side,
and output connections are on the right side. The input terminal block is
keyed differently from the output terminal block to prevent incorrect
insertion.

Wiring connections for the 1791-IOBW and -IOVW are shown in Tables

2.A through 2.D.

Catalog Number 1794IOBW Catalog Number 1794IOVW

Input Terminal Wiring Input Terminal Wiring

Groups 0 and 1 (TRM1) Table 2.A, page 24 Groups 0 and 1 (TRM1) Table 2.C, page 26

Output Terminal Wiring Output Terminal Wiring

Groups 0 and 1 (TRM3) Table 2.B, page 25 Groups 0 and 1 (TRM3) Table 2.D, page 27

Remote I/O link wiring connections are shown in Figure 2.3.

2-3

Chapter 2

Installing Block I/O

Table 2.A
1791IOBW

Terminal

Number

1 Common A Common A 19 Common B Common B

2 Input 00 Input 00 20 Input 00 Input 00

3 Input 01 Input 01 21 Input 01 Input 01

4 Input 02 Input 02 22 Input 02 Input 02

5 Input 03 Input 03 23 Input 03 Input 03

6 Input 04 Input 04 24 Input 04 Input 04

7 Input 05 Input 05 25 Input 05 Input 05

8 Input 06 Input 06 26 Input 06 Input 06

9 Input 07 Input 07 27 Input 07 Input 07

10 Input 10 Input 08 28 Input 10 Input 08

11 Input 11 Input 09 29 Input 11 Input 09

12 Input 12 Input 10 30 Input 12 Input 10

13 Input 13 Input 11 31 Input 13 Input 11

14 Input 14 Input 12 32 Input 14 Input 12

15 Input 15 Input 13 33 Input 15 Input 13

16 Input 16 Input 14 34 Input 16 Input 14

17 Input 17 Input 15 35 Input 17 Input 15

18 N.C. N.C. 36 N.C. N.C.

Input Assignment

Group 0

PLC SLC

Terminal

Number

37 N.C. N.C.

Input T

Input Assignment

Group 1

PLC SLC

erminal W

iring for Groups 0 and 1 (TRM1)

+V

Common

2

36 37

PLC SLC

1

COM

00

01

02

03

04

06

10

12

14

16

17

NC

COM
00

01

02

04

06

10

12

14

16

17

NC

INPUT

05

07

11

13

15

03

05

07

11

13

15

NC

INPUT

COM

00

01

02

03

04

05

06

0

1

07

0

08

09

10

11

12

13

14

15

NC

COM
00

01

02

03

04

05

06

07

08

09

10

11

12

1

13

14

15

NC

NC

12496I

2-4

Chapter 2

Installing Block I/O

Table 2.B
1791IOBW

Terminal

Number

1 N.C. N.C. 20 Common A Common A

2 Common B Common B 21 Output 17 Output 15

3 Output 17 Output 15 22 Output 16 Output 14

4 Output 16 Output 14 23 Output 15 Output 13

5 Output 15 Output 13 24 Output 14 Output 12

6 Output 14 Output 12 25 Output 13 Output 11

7 Output 13 Output 11 26 Output 12 Output 10

8 Output 12 Output 10 27 Output 11 Output 09

9 Output 11 Output 09 28 Output 10 Output 08

10 Output 10 Output 08 29 Output 07 Output 07

11 Output 07 Output 07 30 Output 06 Output 06

12 Output 06 Output 06 31 Output 05 Output 05

13 Output 05 Output 05 32 Output 04 Output 04

14 Output 04 Output 04 33 Output 03 Output 03

15 Output 03 Output 03 34 Output 02 Output 02

16 Output 02 Output 02 35 Output 01 Output 01

17 Output 01 Output 01 36 Output 00 Output 00

18 Output 00 Output 00 37 VDC A VDC A

19 VDC B VDC B

Output Assignment

Group 1

PLC SLC

Terminal

Number

Output T

Output Assignment

Group 0

PLC SLC

erminal W

iring for Groups 0 and 1 (TRM2)

PLCSLC

OUTPUT

+VDC

05

07

09

11

0

13

15

+VDC

01

03

05

07

09

11

13

15

COM

1

NC

01

03

COM

00

L

02

04

06

08

10

12

14

00
L

02

04

06

08

10

12

14

OUTPUT

+VDC

03

05

07

11

13

0

15

17

+VDC

01

03

05

07

11

13

15

17

COM

1

NC

01

COM

L

00
L

02

04

06

10

12

14

16

00

02

04

06

10

12

14

16

1

3637

+VDC

Field
Device

Field
Device

Field
Device

Field
Device

2

Common

12497I

2-5

Chapter 2

Installing Block I/O

Table 2.C
1791IOVW

Input Assignment

Terminal

Number

Group 0

Terminal

Number

PLC SLC

1 VDC A VDC A 19 VDC B VDC B

2 Input 00 Input 00 20 Input 00 Input 00

3 Input 01 Input 01 21 Input 01 Input 01

4 Input 02 Input 02 22 Input 02 Input 02

5 Input 03 Input 03 23 Input 03 Input 03

6 Input 04 Input 04 24 Input 04 Input 04

7 Input 05 Input 05 25 Input 05 Input 05

8 Input 06 Input 06 26 Input 06 Input 06

9 Input 07 Input 07 27 Input 07 Input 07

10 Input 10 Input 08 28 Input 10 Input 08

11 Input 11 Input 09 29 Input 11 Input 09

12 Input 12 Input 10 30 Input 12 Input 10

13 Input 13 Input 11 31 Input 13 Input 11

14 Input 14 Input 12 32 Input 14 Input 12

15 Input 15 Input 13 33 Input 15 Input 13

16 Input 16 Input 14 34 Input 16 Input 14

17 Input 17 Input 15 35 Input 17 Input 15

18 N.C. N.C. 36 N.C. N.C.

Input Assignment

Group 1

PLC SLC

37 N.C. N.C.

Input T

erminal W

iring for Groups 0 and 1 (TRM1)

PLC SLC

+VDC

2

36 37

1

+VDC
00

01

02

03

04

05

06

07

10

11

12

13

14

15

16

17

NC

+VDC

00

01

02

03

04

05

06

07

10

11

12

13

14

15

16

17

NC

NC

INPUT

0

1

NC

NC

+VDC
00

02

04

06

08

10

12

14

+VDC

00

02

04

06

08

10

12

14

01

03

05

07

09

11

13

15

01

03

05

07

09

11

13

15

NC

INPUT

0

1

12493I

2-6

Chapter 2

Installing Block I/O

Table 2.D
1791IOVW

Terminal

Number

1 N.C. N.C. 20 Common A Common A

2 Common B Common B 21 Output 17 Output 15

3 Output 17 Output 15 22 Output 16 Output 14

4 Output 16 Output 14 23 Output 15 Output 13

5 Output 15 Output 13 24 Output 14 Output 12

6 Output 14 Output 12 25 Output 13 Output 11

7 Output 13 Output 11 26 Output 12 Output 10

8 Output 12 Output 10 27 Output 11 Output 09

9 Output 11 Output 09 28 Output 10 Output 08

10 Output 10 Output 08 29 Output 07 Output 07

11 Output 07 Output 07 30 Output 06 Output 06

12 Output 06 Output 06 31 Output 05 Output 05

13 Output 05 Output 05 32 Output 04 Output 04

14 Output 04 Output 04 33 Output 03 Output 03

15 Output 03 Output 03 34 Output 02 Output 02

16 Output 02 Output 02 35 Output 01 Output 01

17 Output 01 Output 01 36 Output 00 Output 00

18 Output 00 Output 00 37 VDC A VDC A

19 VDC B VDC B

Output Assignment

Group 1

PLC SLC

Terminal

Number

Output T

Output Assignment

Group 0

PLC SLC

erminal W

iring for Groups 0 and 1 (TRM2)

PLCSLC

OUTPUT

+VDC

01

03

05

07

09

11

0

13

15

COM

+VDC

01

03

05

07

09

11

13

15

COM

1

NC

00

L

02

04

06

08

10

12

14

00
L

02

04

06

08

10

12

14

OUTPUT

+VDC

03

05

07

11

13

0

15

17

+VDC

01

03

05

07

11

13

15

17

COM

1

NC

01

COM

00

L

02

04

06

10

12

14

16

00
L

02

04

06

10

12

14

16

1

+VDC

3637

Field
Device

Field
Device

Field
Device

Field
Device

2

Common

12491I

Table 2.E

Block Designations

Wiring

Connector Designation Description

1 (BLU) Blue wire  RIO

2 (CLR) Clear wire  RIO

Remote I/O Connector

Input Terminals 1 thru 37 See Tables

Output Terminals 1 thru 37 See Tables

Shield Shield  RIO

Chassis GND

Chassis Ground

24VDC RET +24V ground

24VDC +24V dc

2-7

Chapter 2

Installing Block I/O

Power Supply Requirements

An external 24V dc (+10/-25%) power supply is required to power the
block. Total current required to power the block is equal to 100mA.

In addition, the external power supply should have current limiting
capabilities. The voltage range must not exceed 18.0-26.4V dc.

Wiring Requirements

Wiring cable requirements are shown in Table 2.F.

Table 2.F

W

Acceptable

iring Cables for Block I/O Connection

Use Cable Type With

Remote I/O Link Belden 9463

Input and Output wiring

Up to 14AWG (2mm2)Stranded with
3/64 inch (1.2mm) insulation

Figure 2.3
Remote

I/O Link W

GROUP No.

11

2

(CLR)

Shield

1

(BLU)

iring

Chassis

GND

24VDC

RET

24VDC

PLC2, PLC3, PLC5 family programmable
controllers and SLC controllers

All

GROUP No.

TERMINATION
RESISTOR

150 OHM

OFF

82 OHM

2-8

Connnection

1

(BLU)2 (CLR)

Clear Wire X

Blue Wire X

Shield Wire X

10928I

Shield

Chapter 2

Installing Block I/O

Remote

I/O Link W

iring

Blocks must be wired in series as shown in Figure 2.4. Do not attempt to
wire any block in parallel.

The number of blocks used depends not only on the user requirements but
also on the system used.

Figure 2.4

Connection for Block I/O Using PLC2, PLC3 or PLC5 Family

Series
Programmable Controllers

To Programmable Controller,
remote I/O adapter or
Scanner Module

1 I/O Rack

Install terminating resistor on last block.

1 I/O Rack

10929I

2-9

Chapter 2

Installing Block I/O

Termination Resistor

A termination resistor must be used on the last block in the series. A 150
ohm and 82 ohm termination resistors are built into the unit. To select the
termination resistor, position the switch to the desired position as shown in
Figure 2.5.

Extended Node Capability

Figure 2.5

the T

Installing

ermination Resistor

2

(CLR)

Shield

1

(BLU)

24VDC

Chassis

GND

Position switch to connect termination resistor
across 1 and 2 as follows:

150 ohm  position switch at top;
82 ohm resistor  position switch at bottom;
OFF  no resistor  position switch in middle.

RET

24VDC

TERMINATION
RESISTOR

150 OHM

OFF

82 OHM

10930I

If this is the last block on the remote I/O link in a PLC system, you must
use a terminating resistor to terminate both ends of the remote I/O link
(scanner end and last block end). The size of the terminator is determined
by the system configuration.

Older configurations can use a 150 ohm resistor at both ends. With newer
devices that can support it, you can use an 82 ohm termination resistor at
both ends. The 82 ohm terminators provide “extended node” capability
which allows you to have up to 32 physical devices on the RIO link. (The
number of logical racks capable of being addressed by the scanner is not
affected.)

2-10

ATTENTION: Devices that are operating at 230.4K baud must
have 82 ohm terminators in place for proper operation.

Chapter 2

Installing Block I/O

Compatibility

of 1771 I/O
Products with Extended
Node Operation

Certain products are not compatible with extended node capabilities
obtained with the use of 82 ohm terminators. The following table lists
those products that are not compatible.

Device Series

Scanners 1771SN All

1772SD All

1772SD2 All

1

1775SR

1775S4A

1775S4B

Adapters  1771AS All

1771ASB Series A

1771DCM All

Miscellaneous  1771AF All

1771AF1 All

1

When

using PLC3 programmable controllers, you must use a
1775S5 or SR5 scanner module.
or S4B scanner modules.

1

1

Do not use

All

All

All

1775SR, S4A

2-11

Chapter

Configuring Your Block I/O

3

Chapter

Objectives

Setting the Configuration Switches

In this chapter you will learn how to configure your block I/O when used
with PLC family programmable controllers. This includes the following:

setting the configuration switches
addressing the block I/O

To configure your block I/O for SLC family processors, refer to the user
manual for the 1747-SN scanner module.

ATTENTION: This module is not compatible with the
1747-DSN distributed I/O scanner module.

Each block I/O module has switches for setting:

transmission (baud) rate - used to set the communication rate chosen

for the remote I/O link

last state - when last state is enabled, a processor reset will keep the

outputs in their present (last) state; when last state is disabled, the
outputs will reset

processor restart lockout (PRL) - when PRL is enabled, the

programmable controller cannot automatically start up the module’s
communications if the power has been cycled to either the module or
the programmable controller

last rack - used to identify if the module contains the highest numbered

I/O group for the associated rack number

I/O group adress - used to identify which module group (0-1, 2-3, 4-5

or 6-7) the module should assign to its inputs/outputs

rack address - used to select the rack address of the module

RIO termination resistor - used to connect an internal resistor

(82 ohm, 150 ohm, or no resistor) across LINE 1 and 2 on the remote
I/O terminals

These switches are all accessible on the front or top of the module, as
shown in Figure 3.1.

3-1

Chapter 3

Configuring Your Block I/O

Configuration
Switches

Figure 3.1

Setting Locations (1791IOBW shown)

Switch

Rack Address
Switches

COM

00

02

04

06

10

12

14

16

NC

COM

00

02

04

06

10

12

14

16

NC

NC

87654321

01

03

05

07

11

13

15

17

01

03

05

07

11

13

15

17

2

(CLR)

RACK
ADDR

Shield

POWER
ACTIVE
COMM
FUSE

(BLU)

1

Chassis

GND

CONFIGURATION

SWITCHES

INPUT

1791IOBW

64

POINT

24V DC DISTRIBUTED

I/O MODULE

CONFIGURATION

BAUD

1 2

RATE

BPS

PRL

NO OFF
YES ON

4

24VDC

RET

OFF OFF
ON OFF
OFF ON
ON ON

LAST
RACK

NO OFF
YES ON

24VDC

57.6K

115.2KBPS

230.4KBPS
UNUSED

5

OUTPUT

SWITCHES

LAST

3

STATE

LATCH

OFF

RESET

ON

NOT

8

USED

I/O

GROUP

0 to 1
2 to 3
4 to 5
6 to 7

T

ermination Resistor

6

OFF OFF
OFF ON
ON OFF
ON ON

150 Ohm

Off

82 Ohm

7

+VDC

L
01

03

05

07

11

13

15

17
COM

+VDC

01

03

05

07

11

13

15

17

COM

00

02

04

06

10

12

14

16

00

L

02

04

06

10

12

14

16

NC

3-2

Termination

Resistor Switch

10931I

Chapter 3

Configuring Your Block I/O

Rack Address Switch

ON

134256

Set to OFF

I/O Group

0 TO 1
2 TO 3
4 TO 5
6 TO 7

Last

Rack

NO OFF
YES ON

Last Rack Switch 5
PLC2

OFF  When module does not contain the

highest numbered I/O group for the associated
rack number.

ON  When module does contain the highest
numbered I/O group for the associated rack
number.

PLC3

This switch must always be set to OFF."

PLC5

This switch not used.

Figure 3.2
Configuration

8

6

7

OFF OFF
OFF ON
ON OFF
ON ON

5

Switch Settings

COM

00

01

02

03

04

05

RACK

06

07

ADDR

10

11

12

13

14

15

Configuration

8

7

87654321

CONFIGURATION

SWITCHES

INPUT

Switch

(Top View of Switch)

654321

OUTPUT

ON

+VDC

05

07

13

15

00

L
01

02

03

04

06

10

11

12

14

Last State Switch 3
CAUTION: Set switch 3 to the ON

position to deenergize outputs wired to
this module when a fault is detected. If
switch 3 is set to the OFF position,
outputs connected to this module
remain in their last state when a fault
occurs and machine motion may
continue after fault detection.

4

PRL

Disabled OFF
Enabled ON

Processor Restart Lockout (PRL) Switch 4 

When PRL is enabled (on), the programmable
controller cannot automatically start up the module'
communications if the power has been cycled to
either the module or the programmable controller

BAUD RAT E

57.6kbps

115.2kbps

230.4kbps
Unused

AST

L

STATE

Latch
Reset

OFF
ON

s

3

OFF
ON
OFF
ON

1 2

OFF
OFF
ON
ON

10932I

3-3

Chapter 3

Configuring Your Block I/O

Table 3.A

Rack Number for PLC2 Family Processors

I/O

1747SN

Rack

Number

Rack 0 Rack 1 Rack 1 Not Valid Rack 0 Rack 0 0 0 0 0 0 0

Rack 1 Rack 2 Rack 2 Rack 1 Rack 1 Rack 1 0 0 0 0 0 1

Rack 2 Rack 3 Rack 3 Rack 2 Rack 2 Rack 2 0 0 0 0 1 0

Rack 3 Rack 4 Rack 4 Rack 3 Rack 3 Rack 3 0 0 0 0 1 1

1771SN

Rack

Number

Rack 5 Rack 5 Rack 4 Rack 4 Rack 4 0 0 0 1 0 0

Rack 6 Rack 6 Rack 5 Rack 5 Rack 5 0 0 0 1 0 1

Rack 7 Rack 7 Rack 6 Rack 6 Rack 6 0 0 0 1 1 0

PLC2

Rack

Number

PLC5

Rack

Number

Rack 7 Rack 7 Rack 7 0 0 0 1 1 1

Rack 10 Rack 10 Rack 10 0 0 1 0 0 0

Rack 11 Rack 11 Rack 11 0 0 1 0 0 1

Rack 12 Rack 12 Rack 12 0 0 1 0 1 0

Rack 13 Rack 13 Rack 13 0 0 1 0 1 1

Rack 14 Rack 14 Rack 14 0 0 1 1 0 0

Rack 15 Rack 15 Rack 15 0 0 1 1 0 1

Rack 16 Rack 16 Rack 16 0 0 1 1 1 0

Rack 17 Rack 17 Rack 17 0 0 1 1 1 1

Rack 20 Rack 20 Rack 20 0 1 0 0 0 0

Rack 21 Rack 21 Rack 21 0 1 0 0 0 1

Rack 22 Rack 22 Rack 22 0 1 0 0 1 0

Rack 23 Rack 23 Rack 23 0 1 0 0 1 1

Rack 24 Rack 24 Rack 24 0 1 0 1 0 0

Rack 25 Rack 25 Rack 25 0 1 0 1 0 1

Rack 26 Rack 26 Rack 26 0 1 0 1 1 0

Rack 27 Rack 27 Rack 27 0 1 0 1 1 1

PLC5/250

Rack

Number

Rack 30 Rack 30 0 1 1 0 0 0

Rack 31 Rack 31 0 1 1 0 0 1

Rack 32 Rack 32 0 1 1 0 1 0

Rack 33 Rack 33 0 1 1 0 1 1

Rack 34 Rack 34 0 1 1 1 0 0

Rack 35 Rack 35 0 1 1 1 0 1

Rack 36 Rack 36 0 1 1 1 1 0

Rack 37 Rack 37 0 1 1 1 1 1

PLC3

Rack

Number

Rack 40 1 0 0 0 0 0

Rack 41 1 0 0 0 0 1

Rack 42 1 0 0 0 1 0

Rack 43 1 0 0 0 1 1

Rack Address Switch Position

6 5 4 3 2 1

3-4

Chapter 3

Configuring Your Block I/O

1747SN

1747SN

Rack

Rack

Number

Number

Rack

address 77 is an illegal configuration.
PLC5/1
PLC5/15 and PLC5/20 processors can scan racks 0103.
PLC5/25 and PLC5/30 processors can scan racks 0107.
PLC5/40 and PLC5/40L processors can scan racks 0117.
PLC5/60 and PLC5/60L processors can scan racks 0127.

1771SN

1771SN

Rack

Rack

Number

Number

1 processors can scan rack 03.

PLC2

PLC2

Rack

Rack

Number

Number

PLC5

PLC5

Rack

Rack

Number

Number

PLC5/250

PLC5/250

Rack

Rack

Number

Number

PLC3

PLC3

Rack

Rack

Number

Number

Rack Address Switch Position

Rack 44 1 0 0 1 0 0

Rack 45 1 0 0 1 0 1

Rack 46 1 0 0 1 1 0

Rack 47 1 0 0 1 1 1

Rack 50 1 0 1 0 0 0

Rack 51 1 0 1 0 0 1

Rack 52 1 0 1 0 1 0

Rack 53 1 0 1 0 1 1

Rack 54 1 0 1 1 0 0

Rack 55 1 0 1 1 0 1

Rack 56 1 0 1 1 1 0

Rack 57 1 0 1 1 1 1

Rack 60 1 1 0 0 0 0

Rack 61 1 1 0 0 0 1

Rack 62 1 1 0 0 1 0

Rack 63 1 1 0 0 1 1

Rack 64 1 1 0 1 0 0

Rack 65 1 1 0 1 0 1

Rack 66 1 1 0 1 1 0

Rack 67 1 1 0 1 1 1

Rack 70 1 1 1 0 0 0

Rack 71 1 1 1 0 0 1

Rack 72 1 1 1 0 1 0

Rack 73 1 1 1 0 1 1

Rack 74 1 1 1 1 0 0

Rack 75 1 1 1 1 0 1

Rack 76 1 1 1 1 1 0

Not Valid 1 1 1 1 1 1

123456

Each block uses 2 words of output image table memory and 2 words of
input image table memory. Each block occupies 1/4 rack of data table, with
4 blocks comprising 1 logical rack. Image table usage for one assigned
rack number is shown in Figure 3.3. An example of image table usage is
shown in Figure 3.4.

3-5

Chapter 3

Configuring Your Block I/O

Figure 3.3

Image T

I/O

1

2

able for One Assigned Rack Number

Block 1 Inputs

Block 2 Inputs

Block 3 Inputs

Block 4 Inputs

0

1

2

3

4

5

6

7

Input Image

710

017

Block 1 Outputs

4 1791IOBW or 1791IOVW per rack
1st 1/4 rack = module group 01
2nd 1/4 rack = module group 23
3rd 1/4 rack = module group 45
4th 1/4 rack = module group 67

PLC2 Example

11100

Type of I/O

1 = Input
0 = Output

I/O Rack Number

Starting

I/O Group

0

110

111

010

011

17 16 15 14 13 12

17 16 15 14 13 12

17 16 15 14 13 12

17 16 15 14 13 12

Rack 1

1791IOVW1791IOBW

Block 2 Outputs

Figure 3.4
Input

T

able Usage Example for One Starting I/O Group with 1791IOBW

and IOVW

PLC3, PLC5, PLC5/250 Example

I/O Bit

I/O Group Number

1791IOVW1791IOBW

Output Image

710

0

1

2

3

4

Block 3 Outputs

Block 4 Outputs

5

6

7

I 1100

Type of I/O

I = Input
O = Output

I/O Rack Number

111076543210

11107654321

111076543210

11107654321

0

0

017

10933I

I/O Bit

I/O Group Number

Input Image

Output Image

3-6

Starting

I/O Group

4

114

115

014

015

17 16 15 14 13 12

17 16 15 14 13 12

17 16 15 14 13 12

11107654321017 16 15 14 13 12

11107654321

111076543210

11107654321

0

0

Input Image

Output Image

10934I

Chapter 3

Configuring Your Block I/O

Table 3.B

Input T

erminal Addressing for Groups 0 and 1 (TRM1)

Input

Group 1

Terminal

Number

Input

Assignment

Group 0

Program
Address

1791IOBW

Terminal

Number

Assignment

1 Common A 19 Common B

2 Input 00 1XY00 20 Input 00 1X(Y+1)00

3 Input 01 1XY01 21 Input 01 1X(Y+1)01

4 Input 02 1XY02 22 Input 02 1X(Y+1)02

5 Input 03 1XY03 23 Input 03 1X(Y+1)03

6 Input 04 1XY04 24 Input 04 1X(Y+1)04

7 Input 05 1XY05 25 Input 05 1X(Y+1)05

8 Input 06 1XY06 26 Input 06 1X(Y+1)06

9 Input 07 1XY07 27 Input 07 1X(Y+1)07

10 Input 10 1XY10 28 Input 10 1X(Y+1)10

11 Input 11 1XY11 29 Input 11 1X(Y+1)11

12 Input 12 1XY12 30 Input 12 1X(Y+1)12

13 Input 13 1XY13 31 Input 13 1X(Y+1)13

14 Input 14 1XY14 32 Input 14 1X(Y+1)14

15 Input 15 1XY15 33 Input 15 1X(Y+1)15

16 Input 16 1XY16 34 Input 16 1X(Y+1)16

17 Input 17 1XY17 35 Input 17 1X(Y+1)17

18 N.C. 36 N.C.

37 N.C.

Where: X = Rack Number (1, 2, 3 ...)

Y = Module Group (0, 2, 4, 6)

NOTE:

I XY00

I/O Group
Number

Type

of I/O

1 = Input

0 = Output

I/O Rack
Number

PLC2 Example

1 XY00

I/O Group
Number

I/O Bit

Type

of I/O

I = Input

O = Output

I/O Rack
Number

PLC3, PLC5, PLC5/250 Example

Program

Address

I/O Bit

2

36 37

1

INPUT

COM

00

01

02

03

04

05

06

07

10

11

12

13

14

15

16

NC

COM

00

02

04

06

10

12

14

16

NC

0

17

01

03

05

07

11

13

15

1

17

NC

10935I

3-7

Chapter 3

Configuring Your Block I/O

Table 3.C
1791IOBW

Terminal

Number

1 N.C. 20 Ground A

2 Ground B 21 Output 17 0XY17

3 Output 17 0X(Y+1)17 22 Output 16 0XY16

4 Output 16 0X(Y+1)16 23 Output 15 0XY15

5 Output 15 0X(Y+1)15 24 Output 14 0XY14

6 Output 14 0X(Y+1)14 25 Output 13 0XY13

7 Output 13 0X(Y+1)13 26 Output 12 0XY12

8 Output 12 0X(Y+1)12 27 Output 11 0XY11

9 Output 11 0X(Y+1)11 28 Output 10 0XY10

10 Output 10 0X(Y+1)10 29 Output 07 0XY07

11 Output 07 0X(Y+1)07 30 Output 06 0XY06

12 Output 06 0X(Y+1)06 31 Output 05 0XY05

13 Output 05 0X(Y+1)05 32 Output 04 0XY04

14 Output 04 0X(Y+1)04 33 Output 03 0XY03

15 Output 03 0X(Y+1)03 34 Output 02 0XY02

16 Output 02 0X(Y+1)02 35 Output 01 0XY01

17 Output 01 0X(Y+1)01 36 Output 00 0XY00

18 Output 00 0X(Y+1)00 37 VDC A

19 VDC B

Where: X = Rack Number (1, 2, 3 ...)

Output

Assignment

Group 1

Program
Address

Y = Module Group (0, 2, 4, 6)

Terminal

Number

Output T

Output

Assignment

Group 0

NOTE:

O XY00

Type

of I/O

1 = Input

0 = Output

I/O Rack
Number

PLC2 Example

0 XY00

I/O Group
Number

I/O Bit

Type

of I/O

I = Input

O = Output

I/O Rack
Number

PLC3, PLC5, PLC5/250 Example

erminal Addressing for Groups 0 and 1 (TRM2)

Program

Address

I/O Bit

I/O Group
Number

OUTPUT

0

+VDC

1

+VDC

L
01

03

05

07

11

13

15

17

COM

L
01

03

05

07

11

13

15

17

COM

NC

00

02

04

06

10

12

14

16

00

02

04

06

10

12

14

16

36

37

12

10937I

3-8

Chapter 3

Configuring Your Block I/O

Table 3.D

Input T

erminal Addressing for Groups 0 and 1 (TRM1)

Input

Group 1

Terminal

Number

Input

Assignment

Group 0

Program
Address

1791IOVW

Terminal

Number

Assignment

1 VDC A 19 VDC B

2 Input 00 1XY00 20 Input 00 1X(Y+1)00

3 Input 01 1XY01 21 Input 01 1X(Y+1)01

4 Input 02 1XY02 22 Input 02 1X(Y+1)02

5 Input 03 1XY03 23 Input 03 1X(Y+1)03

6 Input 04 1XY04 24 Input 04 1X(Y+1)04

7 Input 05 1XY05 25 Input 05 1X(Y+1)05

8 Input 06 1XY06 26 Input 06 1X(Y+1)06

9 Input 07 1XY07 27 Input 07 1X(Y+1)07

10 Input 10 1XY10 28 Input 10 1X(Y+1)10

11 Input 11 1XY11 29 Input 11 1X(Y+1)11

12 Input 12 1XY12 30 Input 12 1X(Y+1)12

13 Input 13 1XY13 31 Input 13 1X(Y+1)13

14 Input 14 1XY14 32 Input 14 1X(Y+1)14

15 Input 15 1XY15 33 Input 15 1X(Y+1)15

16 Input 16 1XY16 34 Input 16 1X(Y+1)16

17 Input 17 1XY17 35 Input 17 1X(Y+1)17

18 N.C. 36 N.C.

37 N.C.

Where: X = Rack Number (1, 2, 3 ...)

Y = Module Group (0, 2, 4, 6)

NOTE:

I XY00

I/O Group
Number

Type

of I/O

1 = Input

0 = Output

I/O Rack
Number

1 XY00

I/O Group
Number

I/O Bit

Type

of I/O

I = Input

O = Output

I/O Rack
Number

Program

Address

I/O Bit

2

1

INPUT

COM

00

01

02

03

04

05

06

07

10

11

12

13

14

15

16

NC

COM

00

02

04

06

10

12

14

16

NC

36

37

0

17

01

03

05

07

11

13

15

1

17

NC

10939I

PLC2 Example

PLC3, PLC5, PLC5/250 Example

3-9

Chapter 3

Configuring Your Block I/O

Table 3.E
1791IOVW

Terminal

Number

1 N.C. 20 Ground A

2 Ground B 21 Output 17 0XY17

3 Output 17 0X(Y+1)17 22 Output 16 0XY16

4 Output 16 0X(Y+1)16 23 Output 15 0XY15

5 Output 15 0X(Y+1)15 24 Output 14 0XY14

6 Output 14 0X(Y+1)14 25 Output 13 0XY13

7 Output 13 0X(Y+1)13 26 Output 12 0XY12

8 Output 12 0X(Y+1)12 27 Output 11 0XY11

9 Output 11 0X(Y+1)11 28 Output 10 0XY10

10 Output 10 0X(Y+1)10 29 Output 07 0XY07

11 Output 07 0X(Y+1)07 30 Output 06 0XY06

12 Output 06 0X(Y+1)06 31 Output 05 0XY05

13 Output 05 0X(Y+1)05 32 Output 04 0XY04

14 Output 04 0X(Y+1)04 33 Output 03 0XY03

15 Output 03 0X(Y+1)03 34 Output 02 0XY02

16 Output 02 0X(Y+1)02 35 Output 01 0XY01

17 Output 01 0X(Y+1)01 36 Output 00 0XY00

18 Output 00 0X(Y+1)00 37 VDC A

19 VDC B

Where: X = Rack Number (1, 2, 3 ...)

Output

Assignment

Group 1

Program
Address

Y = Module Group (0, 2, 4, 6)

Terminal

Number

Output T

Output

Assignment

Group 0

NOTE:

O XY00

Type

of I/O

1 = Input

0 = Output

I/O Rack
Number

PLC2 Example

0 XY00

I/O Group
Number

I/O Bit

Type

of I/O

I = Input

O = Output

I/O Rack
Number

PLC3, PLC5, PLC5/250 Example

erminal Addressing for Groups 0 and 1 (TRM2)

Program

Address

I/O Bit

I/O Group
Number

OUTPUT

0

+VDC

1

+VDC

01

03

05

07

11

13

15

17

COM

01

03

05

07

11

13

15

17

COM

NC

00

L

02

04

06

10

12

14

16

00

L

02

04

06

10

12

14

16

36

37

2

1

10941I

3-10

Troubleshooting

Chapter

4

Chapter

Objectives

Indicators

In this chapter you will learn about the indicators on the block I/O module,
and how to use them to troubleshoot the unit.

Each block I/O module has LED indicators (Figure 4.1) which provide
indication of specific functions. Each module has the following:

Status Indicators - Indicators are provided for power, active,
communication and fuse blown indications. An LED array provides
input/output status.

POWER indicator -

-green -on continuously if customer voltage is present;
off if power is not applied or there is an internal power supply
problem.

ACTIVE indicator -

-red if the CPU is not running;
green if the CPU is operating correctly.

COMM indicator - indicates the status of the remote I/O link.

-green when communication is correctly established;
off when communication is not established;
flashing when programmable controller is in PROG mode.

FUSE indicator - indicates the status of the 2 output fuses.

-off if both fuses are intact;
red if either fuse opens.

The I/O status array is an 8 by 8 array of 64 LEDs capable of displaying
the status of 32 inputs and 32 outputs at any one time.

Refer to Table 4.A below for status indications reported by the LED
indicators.

4-1

Chapter 4

Troubleshooting

POWER

ACTIVE

COMM

FUSE

Figure 4.1
Indicators
shown)

on the 1791IOBW and IOVW Block I/O Modules (PLC labels

COM
00

01

02

03

04

06

10

12

14

16

NC
COM

00

01

02

03

04

06

10

12

05

RACK

07

ADDR

11

13

15

17

05

07

11

87654 3 21

CONFIGURATIO
N
SWITCHES

POWER
ACTIVE
COMM
FUSE

+VDC

03

05

07

11

13

15

17

COM

+VDC

03

05

07

11

00

01

02

04

06

10

12

14

16

00

01

02

04

06

10

4-2

INPUT

00

01

02

03

04

05

06

07

OI O I

10

11

12

13

14

15

16

17

OUTPUT

10

00

11

01

12

02

13

03

14

04

15

05

16

06

17

07

10943I

Chapter 4

(green)
ACTIVE

FUSE

Troubleshooting

Table 4.A

roubleshooting Chart

T

Indication Probable Cause Corrective Action

POWER
(green)

COMM
(green)

ACTIVE
(green/red)

FUSE
(red)

Green
I/O status on/off

Off

Solid green

Off

Flashing green

Green

Red

Red

Off

Normal indication None required

No 24V dc power connected, or hardware fault. Check 24V dc power to block

Normal indication  module is communicating with
the programmable controller

No communication with adapter, scanner etc.

Reset command (or output disable bit for SLC) has
been issued by processor, scanner or adapter.
SLC or programmable controller not in run mode.

Normal indication None

Internal CPU fault Return module for repair

One or more fuses are open Replace blown fuse

Normal indication None required

None required

Check that power LED is on. Make sure that
proper number of blocks are configured.

Check program. Correct as necessary.

Place in run mode.

Replacing

a Fuse

The block I/O module has one fuse for each group of outputs. To replace a
fuse, proceed as follows.

1. Remove power to the block I/O module.

ATTENTION: Remove power to the block I/O module before

attempting to replace the fuse.

Failure to remove power from the block I/O module could
cause injury or equipement damage due to possible
unexpected operation.

Failure to remove power from the module could cause
module damage, degradation of performance or injury.

2. Remove the four screws securing the cover to the block I/O module.

3. Locate and remove the blown fuse.

4-3

Chapter 4

Troubleshooting

4. Replace the blown fuse with a 5.0A slow blow fuse.

5. Reinstall cover and secure with four screws removed in step 2.

6. Reapply power to the module.

Summary

In this chapter you learned what the LED indicators represent, and how to
interpret them

4-4

Specifications

General Specifications

Appendix

A

External power

Power Dissipation 15.1 Watts (maximum); 7.6 Watts (typical)

Thermal Dissipation 51.8 BTU/hr (maximum); 25.9 BTU/hr (typical)

Remote I/O Isolation 850V dc (transformer) for 1 second

Interconnect cable length
(PLC or SLC)

Cable requirements RIO - Belden 9463

Dimensions

Conductors Wire Size

Category

Environmental Conditions

Operating Temperature
Storage Temperature
Relative Humidity

Operating
Nonoperating

1

Refer

to publication 1770-4.1, Programmable Controller Wiring and Grounding Guidelines

Range: 18 to 26.4V dc
100mA @ 24V dc; initial surge 2.0A for 10ms

RIO: 57.6K 10,000 cable-feet

115.2K 5,000 cable-feet

230.4K 2,500 cable-feet

Inches: 6.15W x 7.0H x 1.75D
Millimeters: 156.21W x 178.0H x 44.7D

14 gauge (2mm2) stranded (maximum)
3/64 inch (1.2mm) insulation (maximum)

1

2

32 to 140oF (0 to 60oC)

-40 to 185oF (-40 to 85oC)

5 to 95% noncondensing
5 to 80% noncondensing

Input Specifications

Number of Inputs 32 (2 groups of 16)

Input type 1791-IOBW - Sinking; 1791-IOVW - Sourcing

On-state voltage range 12.0 to 26.4V dc

Minimum on-state input current 1.56mA

Maximum off-state voltage 7.0V dc

Maximum off-state current 1.0mA dc

Onstate Current (typical) 5.2mA @ 24V dc

Input Impedance (nominal) 4.6K

Maximum turn on time 10msec (+4ms)

Maximum turn off time 10msec (+4ms)

Input to system isolation 1500V ac (opto) for 1 second

Group to group isolation 1500V ac (air gap) for 1 second

A-1

Appendix A

Specifications

Output Specifications

Number of outputs 32 (2 groups of 16)

Output type 1791-IOBW - Source; 1791-IOVW - Sink

Maximum output voltage range 18.0 to 26.4V dc @ 300mA resistive

Maximum on-state voltage drop 1.5V dc @ 25oC at rated current

Maximum on-state current 300mA per point

Minimum on-state current 5mA

Maximum output current per
output group

Maximum surge current 1.0A for 25ms, 1 pulse per second max.

Maximum off-state voltage 26.4V dc

Maximum off-state leakage
current

Maximum turn on time 2.0ms

Maximum turn off time 2.0ms

Fuse type 5.0A slow blow (5 X 20mm size) - one per group

Output to system isolation 1500V ac (opto) for 1 second

Group to group isolation 1500V ac (air gap) for 1 second

2.4A continuous

0.5mA

A-2

Index

Symbols

**Empty**, 13

B

baud rate, 31, 33

C

compatibility, 11

extended node numbers, 211

configuration switches, 33

setting, 31

connection, in a PLC system, 16

connections, wiring, 23

D

description, P2, 11

IOBX, 13
IOVW, 14

dimensions, mounting, 22

IOVX groups 0 and 1, 39

inputs, sinking, 13

installation, termination resistor, 210

L

last rack, 31, 33

LED indicators, 41

M

mounting, clearance, 23

O

output, sinking, 15

output terminal addressing

IOBX groups 0 and 1, 38
IOVX groups 0 and 1, 310

outputs, sourcing, 14

P

E

extended node capability, 210

F

fuses, removing and replacing, 43

G

group address, 31, 33

I

image table usage, 35

indicators

I/O status array, 13
locations, 42
status, 13
status reported, 41

input, sourcing, 14

input terminal addressing

IOBX groups 0 and 1, 37

power requirements, 28

processor restart lockout, 31, 42

R

rack address, 31

related publications, P2

S

sinking inputs, 13

description, 13

sourcing outputs, 13

description, 14

specifications, A1

switch

configuration, 12
rack address, 12
termination resistor, 12

switch assemblies, 12

switch selections, I/O rack number, PLC-2,

34

I–2

Index

switch settings, 33

T

termination resistor

installation, 210
internal, 31

troubleshooting chart, 43

W

wiring

block designations, 27

cable requirements, 28
IOBX input terminals, 0 and 1, 24
IOBX output terminals, 0 and 1, 25
IOVX input terminals, 0 and 1, 26
IOVX output terminals, 0 and 1, 27
remote I/O link, 28

wiring connections, 23

wiring terminals, 12

Worldwide representation.

AllenBradley, a Rockwell Automation Business, has been helping its customers improve
productivity and quality for more than 90 years. We design, manufacture and support a broad
range of automation products worldwide. They include logic processors, power and motion
control devices, operator interfaces, sensors and a variety of software. Rockwell is one of the
worlds leading technology companies.

Argentina •
Denmark • Ecuador
Ireland
Philippines •
Sweden

Australia • Austria • Bahrain

• Egypt • El Salvador • Finland • France •

• Israel • Italy • Jamaica •

• Belgium • Brazil •

Bulgaria • Canada

Germany • Greece • Guatemala • Honduras • Hong Kong • Hungary

Japan • Jordan • Korea • Kuwait • Lebanon

• Chile •

China, PRC • Colombia

• Malaysia • Mexico •

Poland • Portugal • Puerto Rico • Qatar • Romania • Russia-CIS • Saudi Arabia • Singapore

• Switzerland • T

aiwan

• Thailand • T

urkey • United Arab Emirates • United Kingdom • United States • Uruguay

• Costa Rica •

Netherlands

• New Zealand •

• Slovakia • Slovenia •

Croatia • Cyprus

Norway

South Africa, Republic

• V

enezuela

• Iceland •

• Yugoslavia

AllenBradley Headquarters, 1201 South Second Street, Milwaukee, WI 53204 USA, Tel: [phone]2000 Fax: [phone]4444

Publication 1791-6.5.7 - January 1995

Supersedes

publication 17916.5.7 - May 1993

Copyright

• Czech Republic •

India • Indonesia

• Pakistan •

Peru

•

• Spain •

P/N

1995 Allen-Bradley Co. Inc. Printed in USA

955121-07

•