AB Quality ALLEN-BRADLEY 1791 User manual

1791 Analog Block I/O
Input/Output Modules
User Manual

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: Identifies information about practices or
circumstances that can lead to personal injury or death, property
damage or economic loss.
Attention helps you:
- Identify a hazard
- Avoid the hazard
- recognize the consequences
Important: Identifies information that is critical for successful application
and understanding of the product.
Important: We recommend you frequently backup your application
programs on appropriate storage medium to avoid possible data loss.
Important User Information

Summary of Changes
S-1
Summary of Changes
This release of the publication contains new and updated information from
the last release.
New Information
This release includes information on new block I/O modules now
available. This information was not included in the previous release of
this publication. The modules are:
1791-NDV – 24V dc Analog Block I/O (voltage outputs)
1791-NDC – 24V dc Analog Block I/O (current outputs)
Updated Information
Generally, change bars (as shown to the right of this paragraph) are used to
show new or significantly revised copy. Certain additions, such as adding
octal numbering or corrected typographical errors, are not shown by
change bars.
Summary of Changes

Summary of Changes S1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using This Manual P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purpose of Manual P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vocabulary P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Organization P1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block I/O Products Covered by this Publication P2
. . . . . . . . . . . . . . .
Introducing Block I/O 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How
Block I/O Fits in a PLC System 13. . . . . . . . . . . . . . . . . . . . . . .
Inputs 14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scaling 16
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outputs 18
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing Block I/O 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preinstallation Considerations 21
. . . . . . . . . . . . . . . . . . . . . . . . . .
Installing
the Block I/O 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting Wiring 24
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Termination Resistor 213
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote
I/O Link 213. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extended
Node Capability 214. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compatibility of 1771 I/O Products with Extended Node Numbers 215
. .
Selecting
Remote I/O Link Speed 215. . . . . . . . . . . . . . . . . . . . . . . .
Configuring Y our Block I/O for PLC Family
Programmable Controllers 31. . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting
the Configuration Switches 31. . . . . . . . . . . . . . . . . . . . . . . .
Module Scan Time 37
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Block Applications Using Block Transfers 41. . . . . . .
Chapter Objectives 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading Data and Status from the Module 41
. . . . . . . . . . . . . . . . . .
Block Transfer Read Data Format 41
. . . . . . . . . . . . . . . . . . . . . . . .
Configuring
the Module and Setting Outputs with Block T ransfer Write
Instructions 43
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents

Table of Contentsii
Analog Block Applications Using Discrete Transfers 51. . . . .
Chapter Objectives 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Discrete Data Transfer 51
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Data Format 51
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Data Format 52
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming Y our Analog Block I/O Module 61. . . . . . . . . . .
Chapter Objectives 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer Programming 61
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLC3 Program Example 62
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLC5 and PLC-5/250 Program Example 63
. . . . . . . . . . . . . . . . . .
Sample Programs for Analog Block 64
. . . . . . . . . . . . . . . . . . . . . . .
PLC3 Family Processors 64
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLC5 Family Processors 65
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Calibration 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objective 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tools and Equipment 71
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calibrating your Module 71
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Indicators 81
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Preface
P-1
Using This Manual
This manual shows you how to use your block I/O with an Allen-Bradley
programmable controller. It helps you:
install your module
program your module
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” or “processor”
This manual is divided into eight 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
1Introducing Block I/O Description of the modules, including general and
hardware features
2Installing Block I/O Module power requirements, location, and wiring
information
3Configuring Your Block I/O for PLC
Family Programmable Controllers
How to set the configuration switches and address
the block I/O
4Analog Block Applications using Block
Transfers
How to use block transfer programming with your
block I/O
5Analog Block Applications using Discrete
Transfers How to use discrete transfer with your block I/O
6Programming Your Analog Block I/O
Module
Programming examples for analog block I/O and
PLC family controllers
7Module Calibration How to calibrate analog block I/O
8 Troubleshooting How to use the indicators to troubleshoot your block
I/O module
Appendix A Specifications Specifications for the block I/O modules
Purpose of Manual
Audience
Vocabulary
Manual Organization

Using This Manual
Preface
P-2
This publication covers the following analog block I/O products:
Catalog Number Power Supply Voltage Inputs Outputs Description
1791N4V2 120V ac 4 2 analog - 4 input, 2 voltage output
1791N4C2 120V ac 4 2 analog - 4 input, 2 current output
1791NDV 24V dc 4 2 analog - 4 input, 2 voltage output
1791NDC 24V dc 4 2 analog - 4 input, 2 current output
For a list of publications with information on Allen-Bradley products,
consult our publication index (SD499).
Block I/O Products Covered
by this Publication
Related Publications

Chapter 1
1-1
Introducing Block I/O
In this chapter, you will learn what analog 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. Table 1.A is a list of block
I/O modules covered in this publication.
Table 1.A
Types
of Block I/O
Catalog Number Power Supply Voltage Inputs Outputs Description
1791N4V2 120V ac 4 2 analog - 4 input, 2 voltage output
1791N4C2 120V ac 4 2 analog - 4 input, 2 current output
1791NDV 24V dc 4 2 analog - 4 input, 2 voltage output
1791NDC 24V dc 4 2 analog - 4 input, 2 current output
The analog blocks are compatible with PLC-2, PLC-3, PLC-5/250and
PLC-5family programmable controllers, and the SLC5/02 (or greater)
modular controllers. Refer to the table below for information on using
block I/O with various Allen-Bradley programmable controllers.
If You are Using: You must use:
PLC2 family programmable controller 1771SN subI/O scanner or
1772SD and SD2 remote I/O scanners
PLC3 family programmable controller
PLC5 family programmable controller Block attaches directly to controller
PLC5/250 programmable controller
y
SLC 500 programmable controller 1747SN remote I/O scanner
The analog blocks communicate via block transfer or discrete transfer with
any Allen-Bradley programmable controller that connects to the remote
I/O network. The analog blocks communicate with SLC family controllers
using discrete transfer.
Each analog block has four independent inputs, which can be configured as
either all voltage inputs or all current inputs. The block contains a 24V dc
current limited voltage source for accommodating loop-powered current
transducer inputs.
Chapter Objectives
General Description

Introducing Block I/O
Chapter 1
1-2
Analog block outputs are configured at the factory for either a current
output or a voltage output. Outputs are not user-configurable.
Figure 1.1 shows the physical features of the block I/O.
Figure 1.1
Major
Features of the Analog Block I/O Modules (1791N4V2 shown)
2 mounting holes
for 1/4inch screws
1
30
1791N4V2
ANALOG BLOCK
Indicators
Equipment
Grounding
Stud
Removable
Terminal Strip for
Input, Output, Remote
I/O and Power
Connections
Switch
Assemblies
POWER
COMM
FAULT
12631I
Terminal Strip - Remote I/O link, power and input/output connections are
made to the removable terminal strip for easy connection of wiring.
Switch Assembly - The modules contain two switch assemblies. Use these
assemblies to make the following settings:
I/O rack number
starting I/O group
communication rate
last I/O group
last state
transfer type
processor restart/lockout
Status Indicators - Indicators display the status of module power,
communication and fault. Use these indicators to help in troubleshooting.

Introducing Block I/O
Chapter 1
1-3
Block I/O is a complete I/O interface that includes the functionality of the
I/O rack, adapter, power supply, and I/O module in a single unit. Connect
sensors and actuators to the module and use the remote I/O cable to
connect the block I/O to your programmable controller.
Connect the block I/O to your remote I/O link as you would any other
device. Input and output data is scanned asynchronously and transferred
back and forth between the block and the programmable controller using
either block transfer or discrete transfer. When using block transfer
(Figure 1.2), the block looks like a 1/4 I/O rack to the processor (two
words of input image table memory and two words of output image table
memory). Block transfer provides the most efficient use of your data table
image memory, and allows access to all implemented user functions of
the block.
Figure 1.2
Block
I/O Connection in a PLC System using block transfer
Blocks are daisychained to
a programmable controller or
a scanner
Block I/O  each block
is 1/4 I/O rack
Programmable
Controller
or Scanner
10828I
= 1 I/O Rack
1/4
1/4
1/4
1/4
+
+
+
How Block I/O Fits in a
PLC System

Introducing Block I/O
Chapter 1
1-4
Discrete transfer (Figure 1.3) is intended to be used with controllers which
do not have block transfer capability. However, discrete transfer can be
used with any PLC family controller. When using discrete transfer, the
block looks like a 1/2 I/O rack to the controller (four words of input image
table memory and four words of output image table memory). Note that
certain alarms and user scaling features are not available when using
discrete transfer.
Figure 1.3
Block
I/O Connection in an SLC System using discrete transfer
Blocks are daisychained to
a scanner
1747SN Remote I/O
Scanner Module
10828I
= 1 I/O Rack
Block I/O  each block
is 1/2 I/O rack
+
1/2
1/2
A simplified schematic of the input circuit of one input channel is
shown below.
RET in0
Simplified Schematic
1
1
inV0
inI0
GND in0
A/D
20MΩ
249Ω
20MΩ
Analog Multiplexer Instrumentation
Amplifier
Channel 0
Channel 1
Channel 2
Channel 3
Channel 0 Input
+
-
12501-I
Analog Input
Common
ATTENTION: The 249 ohm
input current shunt is rated at
0.25 Watts. Do not exceed this
power rating or apply more
than 6V across the resistor
Analog Input
Common
Inputs have selectable input ranges as shown below.
Application Input Range Resolution
voltage +10V 14 Bits
voltage or current +5V 14 Bits
voltage 0 to 10V 14 Bits
voltage or current 0 to 5V 14 Bits
Inputs

Introducing Block I/O
Chapter 1
1-5
Voltage Input
Voltage inputs can be either single-ended or differential. In the voltage
mode, a signal applied between inV0 and the combination of RET in0
shorted to GND in0 provides a single-ended input mode. A signal applied
between inV0 and RET in0 provides a differential input mode. The four
terminals for ground are internally connected together to form the analog
input common. In either input mode (single-ended or differential) the
common mode voltage between any input terminal and analog input
common cannot exceed 11V or unreliable operation will occur. The figures
below show examples of differential input mode and single-ended input
mode.
10V
GND in0
RET in0
inI0
inV0 10V inV0
RETin0
GNDin0
inI0
Differential Input Mode Singleended Input Mode
(no connection) (no connection)
Current Input
When using the 0–5V or +5V range, an internal precision 249Ωshunt is
provided on each input. Input current is measured when the IIN and VIN
terminals are connected together. To get the proper input voltages, you
must indicate that the current shunt is connected when you configure the
module at powerup. A +24V power supply is provided for two-wire
current transducers.
5V inV0
inI0
RETin0
GNDin0
Current Input
I
Each range setting has a margin of 2.5% to allow for compensation of
system or calibration inaccuracies.

Introducing Block I/O
Chapter 1
1-6
This is illustrated using the +10V scale below:
14 Bits
13.96 Bits
Nominal Range
I1I2I3I4I5
Resolution
Input Signal
Margin Margin
In the above scale, input signals 1 thru 5 produce corresponding internal
analog to digital converter (ADC) binary counts. A full scale (FS) voltage
input produces an internal count of 16383 (input signal 1), while a bottom
scale (BS) voltage input produces an internal count of 0000 (input 5).
During calibration, the module’s representation of the counts are adjusted
so a voltage of nominal full scale (NFS) will produce a count shown as
input signal 2 while the nominal bottom scale voltage (NBS) produces a
count shown as input signal 4. For each range scale, the input voltage
which produces the ADC count of input signals 1 thru 5 in the above scale
are shown below:
Input Signal +/-10V 0-10V +/-5V 0-5V
I110.25V (FS) 10.25V (FS) 5.125V (FS) 5.125V (FS)
I2+10.000V (NFS) 10.00V (NFS) 5.000V (NFS) 5.000V (NFS)
I30.000V 5.00V 0.000V 2.500V
I4-10.000V (NBS) 0.00V (NBS) -5.000V (NBS) 0.000V (NBS)
I5-10.25V (BS) -0.25V (BS) -5.125V (BS) -0.125V (BS)
The input data represented at the module is always the internal ADC binary
counts scaled by values set in the maximum (Smax) and minimum (Smin)
scaler value using a two point scaling method. The input voltage which
produces input signal 2 (Vnfs) is always equal to Smax, and voltage of input
signal 4 (Vnbs) is equal to Smin
as shown below:
Scaling
Voltage Vnfs Vnbs
Smax Smin
I1I2I3I4I5
Input Signal
Scaling

Introducing Block I/O
Chapter 1
1-7
The following equation shows how the module interprets the input data:
Module data = M x V
in
+ B
where:
(Smax
– S
min)
(Vnfs
– V
nbs)
M =
(Smin x V
nfs
) – (S
max
x V
nbs)
(Vnfs – V
nbs)
B =
You can choose one of three scaling methods:
binary counts (module sets scalers)
default scaling (module sets scalers)
user scaling (you set scalers)
User scaling is not available when you select discrete transfer mode.
Binary Counts Scaling
Binary counts scaling mode activates when the module powers up. This
mode guarantees the maximum resolution. The module sets the scalers as
shown in the following table:
Scaler +/-10V 0-10V +/-5V 0-5V
Smax 8191 16383 8191 16383
Smin -8192 0 -8192 0
Default Scaling
Default scaling mode scales inputs to the input stimulus in either millivolts
or microamps. The module sets the scalers as shown in the following
tables:
With Voltage Input Selected
Scaler +/-10V 0-10V +/-5V 0-5V
Smax 10,000mV 10,000mV 5000mV 5000mV
Smin -10,000mV 0mV -5000mV 0mV
With Current Input Selected
Scaler +/-10V 0-10V +/-5V 0-5V
Smax N/A N/A 20000uA 20000uA
Smin N/A N/A -20000uA 0uA

Introducing Block I/O
Chapter 1
1-8
User Scaling
User scaling is available only when using the block transfer mode. This
mode allows you to define Smax and Smin
in engineering units in the block
transfer write data table. The integer range is 32,767 to –32,768.
Important: If the range of user scaling values is set less than the range of
binary counts scaling values, input resolution is sacrificed.
Scaling Example
Using the +10V range scale, the following illustration shows five possible
input signals.
14 Bits
13.96 Bits
Nominal Range
10.25 10 0 -10 -10.25
Resolution
Input Signal
Margin Margin
The following table shows how the five signals will be scaled using each
of the three scaling methods. In the user scaling column, the Smax was set
to represent 5000 and the Smin was set to represent 0.
ItVl
Scaling Method
Input Value Binary Counts Default User
Approx. +10.25V 8395 10250 5062
+10.000V 8191 10000 5000 (Smax)
0.000V 0000 00000 2500
-10.000V -8192 -10000 0000 (Smin)
Approx. -10.25V -8396 -10250 -0062
The type of output your block I/O module has depends on its catalog
number:
1791-N4V2 and 1791-NDV have two +10V voltage outputs
1791-N4C2 and 1791-NDC have two 0-20mA current outputs
For any of the above modules, if your program tries to write a value which
is outside the output range, the output will be clamped at either the
maximum or minimum value. This condition will be indicated in the block
transfer read status word.
Outputs

Introducing Block I/O
Chapter 1
1-9
V oltage Outputs - 1791N4V2 and 1791NDV
A simplified schematic of a +10V output channel is shown below.
2
Opto
Isolation DAC
Precision
Operational
Amplifier
Digital
Output
VOUTS
2
VOUT
VRET
+
-
Isolated Analog
Output Common
2
2
Note: Schematic does not show overvoltage protection circuits. 12501-I
Isolated Analog
Output Common
Isolated Analog
Output Common
The +10V output provides 14 bits of resolution and is capable of driving
loads as small as 1k ohm. The output sacrifices a small amount of the
resolution to provide a margin of 2.5% to allow for system or calibration
inaccuracies as shown below.
14 Bits
13.96 Bits
Nominal Range
Resolution
Margin Margin
10.25 10 0 -10 -10.25
Output Signal
Scaling
The digital data sent to the output is always scaled by the values set in the
maximum (Smax) and minimum (Smin) scaler values using a two point
scaling method. When digital data sent equals Smax, the output produces
+10.000V and the digital data sent equals Smin, the output produces
–10.000V. The following equations shows this relationship:
Vout = M x Module Data + B
where:
20V
(Smax – Smin)
10 x (Smax + Smin)
M =
B = (Smax – Smin)

Introducing Block I/O
Chapter 1
1-10
You can choose one of three scaling methods:
binary counts
default scaling
user scaling
User scaling is not available when you select discrete transfer mode.
The following table shows the output signals produced by various module
data values entered in each of the three scaling methods. In the user scaling
column, Smax was set to 5000 and Smin was set to 0000.
Module Data
Output Signal Binary Counts
Scaling
Default
Scaling
User
Scaling
Approx. +10.25V 8395 10250 5062
+10V 8191 10000 5000 (Smax)
0.000V 0000 00000 2500
-10.00V -8192 -10000 0000 (Smin)
Approx. -10.25V -8396 -10250 -0062
Current Outputs - 1791N4C2 and 1791NDC
A simplified schematic of a 0 to 20mA output channel is shown below.
2
Opto
Isolation DAC
Digital
Output
IOUTS
IOUT
IRET
2
Note: Schematic does not show overvoltage protection circuits.
High Side
Current
Monitor
-15V
+15V
12505-I
Isolated Analog
Output Common
Isolated Analog
Output Common
The 0 to 20mA output provides 13 bits of resolution and is capable of
driving loads as large as 1k ohm.

Introducing Block I/O
Chapter 1
1-11
The output sacrifices a small amount of the resolution to provide a margin
of 2.5% to allow for system or calibration inaccuracies as shown below.
13 Bits
12.9 Bits
Nominal Range
20.5 20 10 0.0 –0.5
Resolution
Input Signal
Margin Margin
Scaling
The digital data sent to the output is always scaled by the values set in the
maximum (Smax) and minimum (Smin) scaler values using a two point
scaling method. When digital data sent equals Smax, the output produces
20.000mA and the digital data sent equals Smin, the output produces
0.000mA. The following equations shows this relationship:
Iout = M x Module Data + B
where:
20mA
(Smax – Smin)
20mA x (Smax + Smin)
M =
B = (Smax – Smin)
You can choose one of three scaling methods:
binary counts
default scaling
user scaling
User scaling is not available when you select discrete transfer mode.
The following table shows the output signals produced by various module
data values entered in each of the three scaling methods. In the user scaling
column, Smax was set to 5000 and Smin was set to 0000.
Output Signal
Module Data
Output Signal Binary Counts Scaling Default Scaling User Scaling
Nominally +20.5mA 8395 10250 5062
20.000mA 8191 10000 5000 (Smax)
0.000mA 0000 00000 2500 (Smin)
Nominally -0.5mA1-0396 -00050 -2437
1
The actual output can never go negative. However , some of the output range is used to allow for zero of fset
compensation.

Chapter 2
2-1
Installing Block I/O
In this chapter, you will learn how to mount the block, connect the remote
I/O link, connect the input and output wiring to the block, and terminate
the remote I/O link.
Before installation, you must determine the:
scanner/processor to use
number of blocks on your network
throughput requirements
total distance of the installation
transmission rate desired
external fuses required (if any)
Acceptable combinations are shown in Table 2.A.
Table 2.A
Acceptable
Combinations of Processor and Block I/O
When using and Maximum Capacity Baud Rate
Used
Maximum
Network Distance
1771

SN
14 blocks with 150 ohm terminator 57.6K 10,000 cablefeet
PLC

2 family
1
77
1

SN
14
blocks
with
150
ohm
terminator
and discrete transfer 115.2K 5,000 cablefeet
PLC

2
f
am
il
y
1772

SD 1772

SD2
16 blocks/channel, 28 blocks/scanner 57.6K 10,000 cablefeet
1
77
2

SD
,
1
77
2

SD2
16
blocks/channel
,
28
blocks/scanner
with 150 ohm terminator 115.2K 5,000 cablefeet
Any PLC

3 scanner module
16 blocks/channel, 64 blocks/scanner
with 150 ohm terminator. 128 blocks
57.6K 10,000 cablefeet
PLC 3 f il
A
ny
PLC

3
scanner mo
d
u
l
e
with
150
ohm
terminator
.
128
blocks
with 2 scanners and 150 ohm
terminator. 115.2K 5,000 cablefeet
PLC3 family
32 blocks/channel, 64 blocks/scanner 57.6K 10,000 cablefeet
1775S5, or SR5 module
32
blocks/channel
,
64
blocks/scanner
with 82 ohm terminator. 128 blocks
with 2 scanners, 82 ohm terminator 115.2K 5,000 cablefeet
with
2
scanners
,
82
ohm
terminator
and extended node addressing. 230.4K 2,000 cablefeet
PLC5VME (6008LTV) 4 blocks with 150 ohm terminator 57.6K 10,000 cablefeet
PLC

5 family
57.6K 10,000 cablefeet
PLC
5
f
am
il
y
PLC5/11 4 blocks with 150 ohm terminator 115.2K 5,000 cablefeet
230.4K 2,500 cablefeet
Chapter Objectives
Preinstallation
Considerations

Installing Block I/O
Chapter 2
2-2
Maximum
Network Distance
Baud Rate
Used
Maximum CapacityandWhen using
PLC5/15112 blocks with 150 ohm terminator 57.6K 10,000 cablefeet
57.6K 10,000 cablefeet
PLC5/20 12 blocks with 82 ohm or 150 ohm
terminator 115.2K 5,000 cablefeet
terminator
230.4K 2,500 cablefeet
PLC5/25216 blocks with 150 ohm terminator, 28 blocks with 82 ohm terminator and
extended node addressing
57.6K 10,000 cablefeet
16 blocks/channel, 28 blocks per 57.6K 10,000 cablefeet
16
blocks/channel
,
28
blocks
per
processor with 150 ohm terminator 115.2K 5,000 cablefeet
PLC5/30
28 blocks/channel 28 blocks per
57.6K 10,000 cablefeet
28
bl
oc
k
s
/
c
h
anne
l
,
28
bl
oc
k
s per
processor with 82 ohm terminator
and extended node addressing
115.2K 5,000 cablefeet
and extended node addressing 230.4K 2,500 cablefeet
16 blocks/channel, 60 blocks per 57.6K 10,000 cablefeet
16
blocks/channel
,
60
blocks
per
processor with 150 ohm terminator 115.2K 5,000 cablefeet
PLC5/40
32 blocks/channel 60 blocks per
57.6K 10,000 cablefeet
32
bl
oc
k
s
/
c
h
anne
l
,
60
bl
oc
k
s per
processor with 82 ohm terminator
and extended node addressing
115.2K 5,000 cablefeet
PLC5 family (continued)
and extended node addressing 230.4K 2,500 cablefeet
16 blocks/channel, 32 blocks per 57.6K 10,000 cablefeet
16
blocks/channel
,
32
blocks
per
processor with 150 ohm terminator 115.2K 5,000 cablefeet
PLC5/40L
32 blocks/channel 60 blocks per
57.6K 10,000 cablefeet
32
bl
oc
k
s
/
c
h
anne
l
,
60
bl
oc
k
s per
processor with 82 ohm terminator
and extended node addressing
115.2K 5,000 cablefeet
and extended node addressing 230.4K 2,500 cablefeet
16 blocks/channel, 64 blocks per 57.6K 10,000 cablefeet
16
blocks/channel
,
64
blocks
per
processor with 150 ohm terminator 115.2K 5,000 cablefeet
PLC5/60
32 blocks/channel 92 blocks per
57.6K 10,000 cablefeet
32
bl
oc
k
s
/
c
h
anne
l
,
92
bl
oc
k
s per
processor with 82 ohm terminator
and extended node addressing
115.2K 5,000 cablefeet
and extended node addressing 230.4K 2,500 cablefeet
16 blocks/channel, 32 blocks per 57.6K 10,000 cablefeet
16
blocks/channel
,
32
blocks
per
processor with 150 ohm terminator 115.2K 5,000 cablefeet
PLC5/60L
32 blocks/channel 64 blocks per
57.6K 10,000 cablefeet
32
bl
oc
k
s
/
c
h
anne
l
,
6
4
bl
oc
k
s per
processor with 82 ohm terminator
and extended node addressing
115.2K 5,000 cablefeet
and extended node addressing 230.4K 2,500 cablefeet