Rockwell Automation 1771-IGD User Manual

Installation Instructions

TTL Input Module

Cat. No. 1771–IGD

To The Installer

Important User Information

Use this document as a guide when installing the catalog number
1771-IGD TTL input module.

For information on: See page

Important User Information 1

Preinstallation Considerations 3

Calculate Power Requirements 4
Initial Handling 4
Set the Logic Level 5

Key the Backplane Connector 6

Install the Module and Field Wiring Arm 7

Connect Wiring to the Output Module 8

Replacing the Fuse 11

For this reference information See page

Intepreting the Status Indicators 11
Specifications 11

Because of the variety of uses for the products described in this
publication, those responsible for the application and use of these
products 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. In no event will Rockwell Automation be
responsible or liable for indirect or consequential damage resulting
from the use or application of these products.

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

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TTL Input Module2

T

Allen–Bradley publication SGI–1.1, Safety Guidelines for
Application, Installation, and Maintenance of Solid–State Control
(available from your local Rockwell Automation office), describes
some important differences between solid–state equipment and
electromechanical devices that 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 part, without written permission of Rockwell Automation,
is prohibited.

Throughout this publication, notes may be used to make you aware
of safety considerations. The following annotations and their
accompanying statements help you to identify a potential hazard,
avoid a potential hazard, and recognize the consequences of a
potential hazard.

WARNING

!

ATTENTION

!

IMPORTAN

Identifies information about practices or
circumstances that can cause an explosion in a
hazardous environment, which may lead to
personal injury or death, property damage, or
economic loss.

Identifies information about practices or
circumstances that may lead to personal injury or
death, property damage, or economic loss.

Identifies information that is critical for
successful application and understanding of the
product.

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TTL Input Module 3

ATTENTION

!

Environment and Enclosure

This equipment is intended for use in a Pollution
Degree 2 industrial environment, in overvoltage
Category II applications (as defined in IEC
publication 60664–1), at altitudes up to 2000
meters without derating.

This equipment is considered Group 1, Class A
industrial equipment according to IEC/CISPR
Publication 11. Without appropriate precautions,
there may be potential difficulties ensuring
electromagnetic compatibility in other
environments due to conducted as well as radiated
disturbance.

This equipment is supplied as “open type”
equipment. It must be mounted within an
enclosure that is suitably designed for those
specific environmental conditions that will be
present, and appropriately designed to prevent
personal injury resulting from accessibility to live
parts. The interior of the enclosure must be
accessible only by the use of a tool. Subsequent
sections of this publication may contain additional
information regarding specific enclosure type
ratings that are required to comply with certain
product safety certifications.

PreĆinstallation
Considerations

See NEMA Standards publication 250 and IEC
publication 60529, as applicable, for explanations
of the degrees of protection provided by different
types of enclosures. Also, see the appropriate
sections in this publication, as well as the
Allen–Bradley publication 1770–4.1, (“Industrial
Automation Wiring and Grounding Guidelines”),
for additional installation requirements pertaining
to this equipment.

You can use this module in a Series A or B 1771-A1B, -A2B, -A3B,

-A3B1, and -A4B chassis. The module is also compatible in a
1771-AM1 or -AM2 I/O chassis.

You can use any TTL device that meets the output logic level
specification of -0.2V dc to +0.8V dc (low), and 2.0V dc to 5.25V dc
(high).

This module contains input filtering to limit the effects of voltage
transients caused by contact bounce and/or radiated electrical noise.
The delay due to filtering is less than 1ms.

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TTL Input Module4

For maximum noise immunity, the output of the TTL device should
have a pull-up resistor of 1k ohm (typical). Add an external pull-up
resistor to the output terminals of the device, if necessary. If you add
a pull-up resistor, be sure the TTL device maintains the low state
requirement of -0.2V dc to +0.8V dc with the increased load.

Calculate Power
Requirements

Initial Handling

The TTL module requires power from two sources: the I/O chassis
backplane, and a +5V dc Class 2 power supply that you provide for
transmission of TTL signals.

Backplane

The TTL module receives its power through the 1771 I/O chassis
backplane from the chassis power supply. The module requires
130mA from the output of this supply. Add this to the requirements
of all other modules in the I/O chassis to prevent overloading the
chassis backplane and/or backplane power supply.

Customer Supply

You must provide a separate +5(+
for the TTL inputs of the module and for your TTL output devices.
Your module requires 380mA from the output of your supply. Ripple
should not exceed 50mV peak to peak.

The TTL input module is shipped in static-safe packaging to guard
against electrostatic discharge damage. Observe the following
precautions when handling the module.

ATTENTION

!

Preventing Electrostatic Discharge

This equipment is sensitive to electrostatic
discharge, which can cause internal damage and
affect normal operation. Follow these guidelines
when you handle this equipment:

• Touch a grounded object to discharge potential

static.

0.25)V dc Class 2 power supply

• Wear an approved grounding wriststrap.

• Do not touch connectors or pins on component

boards.

• Do not touch circuit components inside the

equipment.

• If available, use a static–safe workstation.

• When not in use, keep modules in appropriate

static–safe packaging.

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