Rockwell Automation 1790P-4R0 User Manual

CompactBlock LDX
RTD/Resistance
Input Module

1790D-4R0, 1790D-T4R0,
1790P-T4R0

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 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 Allen-Bradley 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, 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 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

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.

!

ATTENTION

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

!

RSNetWorx, RSNetWorx for DeviceNet, RSLogix 500, and RSLogix 5000 are trademarks of Rockwell Automation.

Belden is a trademark of Belden, Inc.

IMPORTANT

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

Rockwell Automation Support

Before you contact Rockwell Automation for technical assistance, we
suggest you please review the troubleshooting information contained
in this publication first.

If the problem persists, call your local Rockwell Automation
representative or contact Rockwell Automation in one of the
following ways:

Phone United

States/Canada

Outside
United
States/Canada

Internet 1. Go to http://www.ab.com

1.440.646.5800

You can access the phone number for your
country via the Internet:

1. Go to http://www.ab.com

2. Click on Product Support
(http://support.automation.rockwell.com)

3. Under Support Centers, click on Contact

Information

2. Click on Product Support
(http://support.automation.rockwell.com)

Your Questions or Comments on this Manual

If you find a problem with this manual, please notify us by using the
enclosed How Are We Doing form.

Overview

Installation and Wiring

Module Data, Status, and Channel
Configuration for DeviceNet

Table of Contents

Chapter 1

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Chapter 2

Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Field Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Chapter 3

Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Accessing Input Image File Data . . . . . . . . . . . . . . . . . . . . 3-1

Input Data File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Filter Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Channel Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Channel Cutoff Frequency . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Effective Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

Determining Module Update Time. . . . . . . . . . . . . . . . . . . 3-9

DeviceNet RTD/Resistance Module (1790D-4R0/T4R0) . . . . 3-9

Configure DeviceNet RTD/Resistance Modules

Using RSNetWorx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Chapter 4

Diagnostics and Troubleshooting

Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Module Operation vs. Channel Operation . . . . . . . . . . . . . 4-2

Power-up Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Channel Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Channel LED Indicator Operation . . . . . . . . . . . . . . . . . . . 4-5

Contacting Rockwell Automation . . . . . . . . . . . . . . . . . . . . 4-6

Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Appendix A

Specifications

i Publication 1790-UM002A-EN-P - May 2002

Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . A-1

DeviceNet Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

PROFIBUS DP Specifications . . . . . . . . . . . . . . . . . . . . . . . A-2

General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

RTD/Resistance Specifications . . . . . . . . . . . . . . . . . . . . . . A-4

Table of Contents ii

Two’s Complement Binary
Numbers

Module Configuration for
PROFIBUS

Appendix B

Positive Decimal Values . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Negative Decimal Values. . . . . . . . . . . . . . . . . . . . . . . . . . B-2

Appendix C

Configure PROFIBUS RTD/Resistance Modules

(1790P-T4R0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Configure RTD/Resistance Modules Using the SST PROFIBUS

Configuration Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Save the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6

Download the Configuration . . . . . . . . . . . . . . . . . . . . . . . C-7

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-9

Publication 1790-UM002A-EN-P - May 2002

Chapter

1

Overview

This chapter describes the four-channel 1790D-4R0/T4R0 RTD/resistance
Input module and explains how the controller reads resistance
temperature detector (RTD) or direct resistance-initiated analog input data
from the module. Included is:

• a general description of hardware features

• an overview of module and system operation

• compatibility

General Description

The 1790D-4R0/T4R0 (1790P-T4R0) module supports RTD and direct
resistance signal measurement applications that require up to four
channels. The module digitally converts analog data and then stores the
converted data in its image table.

The module supports connections from any combination of up to four
input devices. Each channel is individually configurable via software for 2­or 3-wire RTD or direct resistance input devices. Channels are compatible
with 4-wire sensors, but the fourth sense wire is not used. When
configured for RTD inputs, the module can convert the RTD readings into
linearized digital temperature readings in °C or °F. When configured for
resistance analog inputs, the module can convert voltages into linearized
resistance values in ohms. The module assumes that the direct resistance
input signal is linear prior to input to the module.

Each channel provides open-circuit (all wires) and over- and under-range
detection and indication.

IMPORTANT

The module accepts input from RTDs with up to 3 wires.
If your application requires a 4-wire RTD, one of the two
lead compensation wires is not used, and the RTD is
treated like a 3-wire sensor. The third wire provides lead
wire compensation. See Chapter 2, Installation and
Wiring, for more information.

1 Publication 1790-UM002A-EN-P

1-2 Overview

The module supports the following filter frequencies:

• 10 Hz

• 25 Hz

• 50 Hz

• 60 Hz

• 100 Hz

• 250 Hz

• 500 Hz

The module uses five input words for data and status bits. Module
configuration is stored in the module memory. Configuration for
1790D-(T)4R0 is done via RSNetWorx for DeviceNet™ programming
software. See Chapter 3, Module Data, Status, and Channel
Configuration, for details on module configuration. Configuration for
1790P-T4R0 is done via PROFIBUS configuration software. See Appendix
C for details.

RTD Compatibility

An RTD consists of a temperature-sensing element connected by two,
three, or four wires that provide input to the module. The following table
lists the RTD types that you can use with the module, including their
temperature range, effective resolution, and accuracy.

Table 1.1 RTD Specifications

RTD Type Temperature

Range

100ohm Pt/α=0.00385 -200 to +850°C -2000 to +8500 0.1°C ±2.1°C
200ohm Pt/α=0.00385 -200 to +850°C -2000 to +8500 0.1°C ±2.1°C
500ohm Pt/α=0.00385 -200 to +650°C -2000 to +6500 0.1°C ±1.7°C
100ohm Pt/α=0.003916 -200 to +640°C -2000 to +6400 0.1°C ±1.68°C
200ohm Pt/α=0.003916 -200 to +640°C -2000 to +6400 0.1°C ±1.68°C
500ohm Pt/α=0.003916 -200 to +640°C -2000 to +6400 0.1°C ±1.68°C

100ohm Nickel -60 to 250°C -600 to 2500°C 0.1 °C ±0.62°C

120ohm Nickel -80 to 260°C -800 to 2600 0.1°C ±0.68°C

Scaling
(Counts)

Resolution* Accuracy**

(0 to 55°C)

Publication 1790-UM002A-EN-P

200ohm Nickel -60C to 250°C -600 to 2500 0.1°C ±1.62°C

500ohm Nickel -60 to 250°C -600 to 2500 0.1°C ±0.62°C

*Filter set for 10 Hz

**Module only

3

Overview 1-3

Resister Device Compatibility

The following table lists the specifications for the resistance devices that
you can use with the module.

Table 1.2 Resistance Device Specifications

Hardware Features

Resistance Type Range Scaling

Resolution* Accuracy (0 to 55°C)**

(Counts)

Resistance 100mΩ 1 to 650Ω 10 to 6250 100mΩ +
Resistance 10mΩ 1 to 327Ω 100 to 32700 10Ω +

1.25Ω

0.65Ω

*Filter set for 10 Hz
**Module only

The RTD/resistance module contains either a fixed terminal block (or a
removable D-sub connector) providing connections for four 3-wire inputs
for any combination of RTD and resistance input devices. Channels are
wired as differential inputs. The illustration below shows the hardware
features of the module.

1790D-4R0/T4R0 DeviceNet Module

Node Address
Switches

Module and Network
Status Indicators

Panel Mount
Hole

DIN Rail Slot

DeviceNet Network
Connection

CompactBlock LDX

1790D-8BV8V

8 INPUTS/8OUTPUTS-DC POWER

0

0

7

7

RTD/resistance Connections

RTD/resistance
Channel Indicators

43223

(D-sub Connector shown)

Publication 1790-UM002A-EN-P

1-4 Overview

1790P-T4R0 PROFIBUS DP Module

DIN Rail Slot

PROFIBUS Network
Connector

Module Power Connector
(underneath module)

Node Address
Switches

Module and Network
Status Indicators

PROFIBUS
Connector

Panel Mount
Hole

RTD/resistance
Channel Indicators

RTD/resistance Connections
(Terminal block)

31341-M

System Overview

General Diagnostic Features

Module, network, and channel LEDs help you identify the source of
problems that may occur during power-up or during normal channel
operation. The LEDs indicate both status and power. See Chapter 4,
Diagnostics and Troubleshooting, for details on power-up and channel
diagnostics.

The modules communicate to the controller or network scanner via the
DeviceNet™ or PROFIBUS network. The modules also receive 24V dc
power through DeviceNet. An external 24V dc auxiliary source is required
to power the RTD/resistance channels.

System Operation

At power-up, the module performs a check of its internal circuits,
memory, and basic functions. If no faults are found during power-up
diagnostics, the module status LED is turned on (green).

Publication 1790-UM002A-EN-P

Overview 1-5

Once a channel is properly configured and enabled, the module
continuously converts the RTD or resistance input to a value within the
range selected for that channel.

Each time the module reads an input channel, it tests the data for a fault
(over- or under-range or open-circuit condition). If it detects a fault, the
module sets a unique bit in the channel status word. See Input Data File
on page 3-2. The module sends two’s compliment binary converted RTD/
resistance data out over the network. See Appendix B for a description of
two’s compliment binary numbers.

Module Operation - DeviceNet Example

As shown in the block diagram below, each input channel of the module
consists of an RTD/resistance connection that accepts excitation current; a
sense connection that detects lead wire resistance; and a return
connection. The signals are multiplexed to an A/D converter that reads
the RTD or resistance value and the lead wire resistance.

Input

EXC0

SENSE0

RTN0

VA2

CH0

A

B

COM

Auxiliary
24Vdc
Power

1

2

3

Multiplexer

VDC

GND

Channels 1 through 3 same as
channel 0 above.

VA3

Analog
Power
Supply

VA1 VA1

EXC
Current

AIN+1

A/D

AIN+2

A-GND

VA1
VA2
VA3

A-GND

AIN-

VREFVref

Channel Select

Optical
Isolation

43224

Vcc

Micro­ Controller

GND

Vcc

GND

Transmit

Receive

Power
Supply

Network

DeviceNet
24Vdc
Power

From the readings taken by the converter, the module sends RTD or
resistance data through the microcontroller to the DeviceNet network.

The PROFIBUS block diagram is similar.

Publication 1790-UM002A-EN-P

1-6 Overview

Chapter Summary

In this chapter, you learned about the 1790D/4R0/T4R0 and 1790P-TR40
RTD/resistance modules. See Chapter 2 to learn how to install and wire
the modules.

Publication 1790-UM002A-EN-P

Installation and Wiring

Chapter

2

Before You Begin

Power Requirements

This chapter tells you how to:

• determine the power requirements for the modules

• avoid electrostatic damage

• install the module

• wire the module’s terminal block

1790D-4R0/T4R0

The module receives system power from the DeviceNet network. An
auxiliary field supply provides power for the RTD/resistance channels.

Table 2.1 1790D-4R0/T4R0 Power Specifications

Power Specification

DeviceNet Supply voltage - 24V dc nominal

Voltage range - 11-28.8V dc
Power dissipation - 1.2W maximum @ 28.8V dc

Field Supply voltage - 24V dc nominal

Voltage range - 21.6-26.4V dc (+
Power dissipation - 1.5W maximum @ 26.4V dc

10%)

1790P-T4R0

The module requires external supplies for both system power and for the
RTD/resistance channels.

Table 2.2 1790P-T4R0 Power Specifications

Power Specification

PROFIBUS Supply voltage - 24V dc nominal

Voltage range - 19.2-28.8V dc
Power dissipation - 2W maximum @ 28.8V dc

Field Supply voltage - 24V dc nominal

Voltage range - 21.6-26.4V dc (+
Power dissipation - 1.5W maximum @ 26.4V dc

1 Publication 1790-UM002A-EN-P

10%)

2-2 Installation and Wiring

General Considerations

The modules are suitable for use in a commercial or light industrial
environment when installed in accordance with these instructions.
Specifically, this equipment is intended for use in clean, dry environments

(1)

(Pollution degree 2

(2)

Category II

(IEC 60664-1).

) and to circuits not exceeding Over Voltage

(3)

Hazardous Location Considerations

This equipment is suitable for use in Class I, Division 2, Groups A, B, C, D
or non-hazardous locations only. The following WARNING statement
applies to use in hazardous locations.

WARNING

ÿ

EXPLOSION HAZARD

• Substitution of components may impair suitability for

Class I, Division 2.

• Do not replace components or disconnect equipment

unless power has been switched off or the area is
known to be non-hazardous.

• Do not connect or disconnect components unless

power has been switched off or the area is known to be
non-hazardous.

• This product must be installed in an enclosure.

• All wiring must comply with N.E.C. article 501-4(b).

Publication 1790-UM002A-EN-P

(1)

Pollution Degree 2 is an environment where, normally, only non-conductive pollution occurs except that occasionally
a temporary conductivity caused by condensation shall be expected.

(2)

Over Voltage Category II is the load level section of the electrical distribution system. At this level transient voltages
are controlled and do not exceed the impulse voltage capability of the product’s insulation.

(3)

Pollution Degree 2 and Over Voltage Category II are International Electrotechnical Commission (IEC) designations.

Installation and Wiring 2-3

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.

ATTENTION

ÿ

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.

See NEMA Standards publication 250 and IEC
publication 60529, as applicable, for explanations of the
degrees of protection provided by different types of
enclosure. 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.

Publication 1790-UM002A-EN-P

2-4 Installation and Wiring

ATTENTION

ÿ

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.

• 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, store the equipment in appropriate

static-safe packaging.

WARNING

ÿ

If you insert or remove the module while power is on,
an electrical arc can occur. This could cause an
explosion in hazardous location installations.

Be sure that power is removed or the area is
nonhazardous before proceeding.

Selecting a Location

Reducing Noise

Most applications require installation in an industrial enclosure to reduce
the effects of electrical interference. RTD inputs are highly susceptible to
electrical noise. Electrical noise coupled to the RTD inputs will reduce the
performance (accuracy) of the module.

Group your modules in the enclosure to minimize adverse effects from
radiated electrical noise and heat. Consider the following conditions when
selecting a location for the module. Position the module:

• away from sources of electrical noise such as hard-contact switches,

relays, and AC motor drives

Publication 1790-UM002A-EN-P

• away from modules which generate significant radiated heat.

In addition, route shielded, twisted-pair wiring away from any high
voltage I/O wiring.

Installation and Wiring 2-5

Protecting the Circuit Board from Contamination

The printed circuit boards of analog modules must be protected from dirt,
oil, moisture, and other airborne contaminants. To protect these boards,
the system must be installed in an enclosure suitable for the environment.
The interior of the enclosure should be kept clean and the enclosure door
should be kept closed whenever possible.

Installing CompactBlock LDX I/O

Follow these steps to install the block:

1. Set the node address on the base block.

2. Mount the base block.

3. Wire the terminal blocks.

4. Connect the network cable.

These steps are explained in detail in the following procedures for
both the 1790D-4R0/T4R0 DeviceNet and 1790P-T4R0 PROFIBUS DP
modules.

Set the Node Address on the DeviceNet 1790D-4R0/T4R0 Base Block

Each base block comes with its internal program set for node address 63.
To reset the node address, adjust the switches on the front of the block.
The two switches are most significant digit (MSD) and least significant
digit (LSD). The switches can be set between 00 and 63.

The rotary switches are read at block power up only. Switch settings
between 64 and 99 cause the block to use the last valid node address
stored internally.

Example: Node
Address is set at 26

The node address may also be set through RSNetWorx for DeviceNet or a
similar configuration tool. When software configuration is used for the
node address, the switches must be set between 64 and 99.

43230

Publication 1790-UM002A-EN-P

2-6 Installation and Wiring

Set the Station Address on the 1790P-T4R0 PROFIBUS DP Base Block

To set the station address, adjust the switches on the front of the base
block. The two switches are most significant digit (MSD) and least
significant digit (LSD). The switches can be set between 00 and 99.

Mounting

The rotary switches are read at base block power up only

Example: Node
Address is set at 26

43230

.

Mount the Base Block

You can mount the base block to a panel or DIN rail. We recommend that
you ground the panel or DIN rail before mounting the block.

IMPORTANT

WARNING

ÿ

The RTD and thermocouple base modules
do not support any expansion blocks.

When used in a Class I, Division 2,
hazardous location, this equipment must
be mounted in a suitable enclosure with
proper wiring method that complies with
the governing electrical codes.

Publication 1790-UM002A-EN-P

Panel Mounting

1. Place the block against the panel where you want to mount it.

2. Gently pull and position the expansion cover to the left.

3. Place a center punch, nail or similar device through the mounting

holes in the block and make two marks on the panel (lower left and
upper right corners of the module).

4. Remove the block and drill two holes in the panel to accommodate

each of the mounting screws.

Installation and Wiring 2-7

5. Replace the block on the panel and place a screw through each of the

two mounting holes. Tighten the screws until the block is firmly in

.

place

95 mm

3.74 in

CompactBlock LDX

41 mm

1.6 in

EXPANSION UNIT

0

0

7

1790-16BVOX

16 INPUTS-DCPOWER

7

Expansion
Cover

43242

DIN Rail Mounting

1. Hook the top slot of the block over the DIN Rail.

2. Pull down on the locking lever while pressing the block against the

.

rail

ÿ

Locking Lever

43243

3. Push up on the locking lever to secure the block to the rail when the

block is flush against the rail.

Publication 1790-UM002A-EN-P

2-8 Installation and Wiring

Connect the DeviceNet Cable to the 1790D-4R0/T4R0 Base Block

Follow these procedures when connecting the DeviceNet cable to the
base block.

The required DeviceNet connector is not supplied with the block - you
must purchase it separately. There are three types of connectors that you
can order directly from Rockwell Automation or your local distributor:

• 1799-DNETCON - 5-position open style connector

• 1799-DNETSCON - 5-position open style connector with locking

screws

• 1799-DNC5MMS - 5-position open style to 5-pin micro male connector

with locking screws

WARNING

If you connect or disconnect the DeviceNet cable
with power applied to this module or any device
on the network, an electrical arc can occur. This
could cause an explosion in hazardous location

ÿ

installations.

Be sure that power is removed or the area is
nonhazardous before proceeding.

Connect the DeviceNet wiring (drop line) to one of the DeviceNet
connectors as shown below. A color-coded wiring diagram is also printed
next to the connector on the left side of the module

CompactBlock LDX

Wiring Diagram for
1799-DNETCON

1790D-8BV8V

8 INPUTS/8OUTPUTS-DC POWER

0

0

7

7

V+ Red

Can_H White

Drain/Shield

Can_L Blue

V- Black

V+ Red

V- Black

Wiring Diagram for
1799-DNC5MMS

Drain/Shield

Can_H White

Can_L Blue

43245

Publication 1790-UM002A-EN-P

Installation and Wiring 2-9

Connect the PROFIBUS DP Terminal Connector to the 1790P-T4R0 Base Block

Follow these procedures to connect the PROFIBUS DP terminal connector
to the base block.

WARNING

ÿ

The required PROFIBUS female 9-pin D-sub connector is not supplied
with the base block - you must purchase it separately.

Before you connect female 9-pin D-sub connector to the base block,
make sure it is wired correctly as shown in the following table.

Pin Number: Name: Description:

1 shield Shield, Protective Ground

2 M24V Minus 24V Output Voltage

3 RxD/TxD-P Receive/Transmit-Data-P

4 CNTR-P Control-p

5 DGND Data Ground

If you connect or disconnect the PROFIBUS
cable with power applied to this module or any
device on the network, an electrical arc can
occur. This could cause an explosion in
hazardous location installations.

Be sure that power is removed or the area is
nonhazardous before proceeding.

Table 2.3 Wiring Descriptions for 9-Pin D-Sub Connector

6 VP Voltage-Plus

7 P24V Plus 24V Output Voltage

8 RxD/TxD-N Receive/Transmit-Data-N

9 CNTR-N Control-N

Publication 1790-UM002A-EN-P

2-10 Installation and Wiring

Module Power Connector
(underneath module)

Once you have properly wired the connector, attach it to the base block
as shown below. Use the locking screws on the connector to fasten it to
the base block.

PROFIBUS Connector

Green - GRD

Black - COM

Red - +24V dc

43249

Connect Power to the 1790P-T4R0 Block

To apply power to the block, refer to the above illustration.

Publication 1790-UM002A-EN-P

Installation and Wiring 2-11

Field Wiring Connections

System Wiring Guidelines

Consider the following when wiring your system:

General

• This product is intended to be mounted to a well-grounded mounting

surface such as a metal panel. Additional grounding connections from
the module’s mounting tabs or DIN rail (if used) are not required
unless the mounting surface cannot be grounded.

• Route field wiring away from any other wiring and as far as possible

from sources of electrical noise, such as motors, transformers,
conductors, and ac devices. As a general rule, allow at least 15.2 cm (6
in.) of separation for every 120V of power.

• Routing field wiring in a grounded conduit can reduce electrical noise.

• If field wiring must cross ac or power cables, ensure that they cross at

right angles.

• To ensure optimum accuracy, limit overall cable impedance by

keeping your cable as short as possible. Locate the I/O system as
close to your sensors or actuators as your application will permit.

• Tighten terminal screws with care. Excessive tightening can strip a

screw.

Shield Grounding

• Use Belden shielded, twisted-pair wire to ensure proper operation

and high immunity to electrical noise. Refer to the following table and
the RTD Wiring Considerations below.

Table 2.4 Belden Shielded Wiring

Configuration

2-wire Belden™ 9501 or equivalent

3-wire
less than 30.48 m (100ft.)

3-wire
greater than 30.48 m (100 ft.) or high humidity conditions

(1) For additional information, see Table 2.5.

Recommended Cable

Belden 9533 or equivalent

Belden 83503 or equivalent

• Under normal conditions, the drain wire and shield junction should be

connected to earth ground, via a panel or DIN rail mounting screw at
the module end.

• Keep shield connection to ground as short as possible.

• If noise persists for a device, try grounding the opposite end of the

cable. (You can only ground one end at a time.)

• Refer to Industrial Automation Wiring and Grounding Guidelines,

Allen-Bradley publication 1770-4.1, for additional information.

(1)

Publication 1790-UM002A-EN-P

2-12 Installation and Wiring

RTD Wiring Considerations

Because the operating principle of the RTD module is based on the
measurement of resistance, take special care when selecting your input
cable. For 2-wire or 3-wire configurations, select a cable that has a
consistent impedance throughout its entire length. Cable specifications are
noted below.

Table 2.5 Cable Specifications

Description Belden #9501 Belden #9533 Belden #83503

When used? For 2-wire RTDs and

potentiometers

Conductors 2, #24 AWG tinned

copper (7 x 32)

Shield Beldfoil aluminum

polyester shield with
copper drain wire

Insulation PVC S-R PVC Teflon

Jacket Chrome PVC Chrome PVC Red Teflon

Agency Approvals NEC Type CM NEC Type CM NEC Art-800, Type CMP

Temperature Rating 80°C 80°C 200°C

IMPORTANT

The RTD module requires three wires to compensate for
lead resistance error. We recommend that you do not

For 3-wire RTDs and
potentiometers.
Short runs less than
100 feet and normal
humidity levels.

3, #24 AWG tinned
copper (7 x 32)

Beldfoil aluminum
polyester shield with
copper drain wire

For 3-wire RTDs and
potentiometers. Long
runs greater than 100
feet or high humidity
levels.

3, #24 AWG tinned
copper (7 x 32)

Beldfoil aluminum
polyester shield with
tinned drain wire

use 2-wire RTDs if long cable runs are required, as it
reduces the accuracy of the system. However, if a
two-wire configuration is required, reduce the effect of
the lead wire resistance by using a lower gauge wire for
the cable (for example, use AWG #16 instead of AWG
#24). The module’s terminal block accepts two AWG #14
gauge wires.

Publication 1790-UM002A-EN-P

When using a 3-wire configuration, the module compensates for
resistance error due to lead wire length. For example, in a 3-wire
configuration, the module reads the resistance due to the length of one of
the wires and assumes that the resistance of the other wire is equal. If the
resistances of the individual lead wires are much different, an error may
exist. The closer the resistance values are to each other, the greater the
amount of error that is eliminated.

IMPORTANT

To ensure temperature or resistance value accuracy, the
resistance difference of the cable lead wires must be
equal to or less than 0.01

Ω .

Installation and Wiring 2-13

To insure that the lead values match as closely as possible:

• Keep lead resistance as small as possible

.

• Use quality cable that has a small tolerance impedance rating.

• Use a heavy-gauge lead wire which has less resistance per foot.

Wire Size and Terminal Screw Torque

Each terminal accepts up to two wires with the following restrictions:

Table 2.6 Wire Size and Terminal Screw Torque

Wire Type Wire Size Terminal Screw

Torque

Solid Cu-90°C (194°F) #14 to #22 AWG 0.68 Nm (6 in-lbs) 0.46 Nm (4.1 in-lbs)

Stranded Cu-90°C (194°F) #16 to #22 AWG 0.68 Nm (6 in-lbs) 0.46 Nm (4.1 in-lbs)

Retaining Screw

To rq ue

Wiring the Modules

ATTENTION

To prevent shock hazard, care should be taken when
wiring the module to analog signal sources. Before
wiring any module, disconnect power from the system
power supply and from any other source to the module.

ÿ

After the module is properly installed, follow the wiring procedure below
and the RTD and potentiometer wiring diagrams on pages 2-15 through
2-16. To ensure proper operation and high immunity to electrical noise,
always use Belden shielded, twisted-pair or equivalent wire.

Cut foil shield
and drain wire

signal wire

Cut foil shield
and drain wire

signal wires (3)

signal wire

43250

signal wire

signal wire

signal wire

signal wire

signal wire

drain wire

drain wire

cable

foil shield

cable

foil shield

Publication 1790-UM002A-EN-P

2-14 Installation and Wiring

To wire your module follow these steps.

1. At each end of the cable, strip some casing to expose the individual

wires.

2. Trim the signal wires to 2-inch (5 cm) lengths. Strip about 3/16 inch (5

mm) of insulation away to expose the end of the wire.

ATTENTION

Be careful when stripping wires. Wire fragments that fall
into a module could cause damage at power up.

ÿ

3. At the module end of the cable, twist the drain wire and foil shield

together, bend them away from the cable, and apply shrink wrap.
Then earth ground via a panel or DIN rail mounting screw at the end
of the module. Keep the length of the drain wire as short at possible.

4. At the other end of the cable, cut the drain wire and foil shield back to

the cable and apply shrink wrap.

5. Connect the signal wires to the terminal block as described for each

type of input. See Wiring RTDs below or Wiring Resistance Devices
(Potentiometers) on page 2-15.

6. Connect the other end of the cable to the analog input device.

7. Repeat steps 1 through 6 for each channel on the module.

Wiring RTDs

Three types of RTDs can be connected to the module:

• 2-wire RTD, which is composed of an RTD EXC (excitation) lead wire

and a RTN (return) lead wire.

• 3-wire RTD, which is composed of a Sense and 2 RTD lead wires

(RTD EXC and RTN).

• 4-wire RTD, which is composed of a Sense and 2 RTD lead wires

(RTD EXC and RTN). The second sense wire from the 4-wire RTD is
left open.

Publication 1790-UM002A-EN-P

2-Wire RTD Configuration

Installation and Wiring 2-15

Add Jumper

CHO_A

CHO_B

COM

3-Wire RTD Configuration

CHO_A

CHO_B

COM

Cable Shield (to Ground)

RTD EXC

Return

Cable Shield (to Ground)

RTD EXC

Sense

Return

RTD EXC

Return

43251

RTD EXC

Sense

Return

43252

4-Wire RTD Configuration

Leave this sensor wire open

RTD EXC

Sense

Return

43253

CHO_A

CHO_B

COM

Cable Shield (to Ground)

RTD EXC

Sense

Return

Wiring Resistance Devices (Potentiometers)

Potentiometer wiring requires the same type of cable as that for the RTDs.
Potentiometers can be connected to the module as a 2-wire or 3-wire
connection as shown in the following figure.

Publication 1790-UM002A-EN-P

2-16 Installation and Wiring

2-Wire Potentiometer Interconnection

Add Jumper

Cable Shield (to Ground)

Potentiometer

CHO_A

CHO_B

COM

Add Jumper

CHO_A

CHO_B

COM

TIP

RTD EXC

Return

Cable Shield (to Ground)

RTD EXC

Return

Potentiometer

43254

The potentiometer wiper arm can be connected to
either the EXC or return terminal depending on
whether you want increasing or decreasing resistance.

3-Wire Potentiometer Interconnection

Cable Shield (to Ground)

RTD EXC

CHO_A

CHO_B

COM

CHO_A

CHO_B

COM

Return

Cable Shield (to Ground)

RTD EXC

Sense

Return

Potentiometer

Run Return and sense wires from the module to
potentiometer terminal and tie terminal to one point.

Potentiometer

43255

Run Return and sense wires from the module to
potentiometer terminal and tie terminal to one point.

Publication 1790-UM002A-EN-P

Installation and Wiring 2-17

Wiring the Terminal Blocks

The following figures show how to wire the terminal blocks.

1790D-4R0-RTD Input Module D-Shell Wiring

+24V

19

+24V

37

GND

18

+24V

36

GND

17

35

GND

NC

16

NC

CH0_B

12

31

COM

CH1_A

30

COM

CH1_B

11

29

COM

NC

NC

CH0_A

15

13

14

34

33

32

NC

NC

10

COM

NC

CH2_B

25

CH3_A

6

24

COM

CH3-B

5

23

COM

NC

CH2_A

9

8

7

28

27

26

COM

COM

COM

Wire pins 17, 18, 19 to Field Power (+) 24V dc
Wire pins 35, 36, 37 to Field Power (-) GND

1790D-T4R0 and 179P-T4R0 RTD Input Module D-Shell Wiring

+24V

1

CH0_A

3

2

GND

CH0-B

CH1_A

5

4

CH1_B

COM

7

6

COM

CH2_A

CH3_A

9

8

10

CH2_B

COM

11

13

12

CH3_B

NC

14

COM

15

NC

17

16

NC

4

COM

18

NC

22

NC

NC

19

3

COM

21

20

NC

43257

NC

2

COM

NC

1

20

43256

Publication 1790-UM002A-EN-P

2-18 Installation and Wiring

Chapter Summary

In this chapter, you learned how to install and wire your modules. See
Chapter 3 to learn about module data, status, and channel configuration
with DeviceNet.

Publication 1790-UM002A-EN-P

Chapter

3

Module Data, Status, and Channel Configuration
for DeviceNet

After installation of the RTD/resistance input module, you must configure
it for operation, usually using the programming software compatible with
the controller (for example, RSLogix 500™ or RSLogix 5000™) or scanner
(RSNetWorx for DeviceNet). Once configuration is complete and reflected
in ladder logic, you will need to get the module up and running and then
verify its operation. This chapter includes information on the following:

• module memory map

• accessing input image file data

• configuring channels

• running the module

Module Memory Map

Input Image

File

Accessing Input Image File Data

The module uses five input words for data and status bits (input image).

Memory Map

Word 0
Word 1
Word 2
Word 3
Word 4

43258

Input Image

5 words

Channel 0 Data Word
Channel 1 Data Word
Channel 2 Data Word
Channel 3 Data Word

Status Bits

Input Image

The input image file represents data words and status words. Input words
0 through 3 hold the input data that represents the value of the analog
inputs for channels 0 through 3. These data words are valid only when
the channel is enabled and there are no errors. Input word 4 holds status
bits.

Five words of the processor input image table are reserved for the
module’s image data. You can access the information in the input image
file using the programming software configuration screen.

1 Publication 1790-UM002A-EN-P

3-2 Module Data, Status, and Channel Configuration for DeviceNet

Input Data File

The input data table lets you access RTD input module read data for use
in the control program, via word and bit access. The data table structure is
shown in the tables below.

Table 3.1 Input Data Table

Word/

Bit

0 RTD Input Data Channel 0

1 RTD Input Data Channel 1

2 RTD Input Data Channel 2

3 RTD Input Data Channel 3

4 Not Used

Word Decimal Bit Description

Read Word 0 Bits 00-15 Channel 0 input data

Read Word 1 Bits 00-15 Channel 1 input data

Read Word 2 Bits 00-15 Channel 2 input data

Read Word 3 Bits 00-15 Channel 3 input data

Read Word 4

15141312111098 6543210

S11 S10 S9 S8 Not Used S3 S2 S1 S0

Table 3.2 Input Data Table

Underrange for individual channels - Bit 00 corresponds to input

Bits 00-03

Bits 04-07 Not used: Set to 0

Bits 08-11 Overrange for individual channels - Bit 08 corresponds to input

Bit 12-15 Not used: Set to 0.

channel 0, bit 01 corresponds to input channel 1 and so on.

When set (1), the input signal is below the input channel’s
minimum range.

channel 0, bit 09 corresponds to input channel 1 and so on.

When set (1), the input signal is above the input channel’s
maximum range, or open RTD is detected.

7

Publication 1790-UM002A-EN-P

Input Data Values

Data words 0 through 3 correspond to channels 0 through 3 and contain
the converted analog input data from the input device.

Under-Range Flag Bits (S0 to S3)

Over-range bits for channels 0 through 3 are contained in word 4, bits 0-3.
When set (1), the under-range flag bit indicates an RTD temperature that
is less than the minimum allowed temperature. The module automatically
resets (0) the bit when the data value is again within the normal operating
range.

Module Data, Status, and Channel Configuration for DeviceNet 3-3

Over-Range Flag Bits (S8 to S11)

Under-range bits for channels 0 through 3 are contained in word 4, bits
8-11. When set (1), the over-range flag bit indicates an RTD temperature
that is greater than the maximum allowed temperature, a resistance input
that is greater than the maximum allowed resistance for the module or an
open channel is detected. The module automatically resets (0) the bit
when the data value is again within the normal operating range.

Data Format

RTD/resistance data is presented in engineering units x1. The engineering
units data format represents real temperature or resistance data provided
by the module. RTD data is reported in either degrees C or degrees F.

Table 3.3 RTD Data Format

Data Format

RTD Input Type Range

100Ω Platinum 385 -200 to +850°C -2000 to [phone] to +15620
200Ω Platinum 385 -200 to +850°C -2000 to [phone] to +15620
500Ω Platinum 385 -200 to +650°C -2000 to [phone] to +12020
100Ω Platinum 3916 -200 to +640°C -2000 to [phone] to +1184
200Ω Platinum 3916 -200 to +640°C -2000 to [phone] to +1184
500Ω Platinum 3916 -200 to +640°C -2000 to [phone] to +1184
100Ω Nickel -60 to +250°C -600 to +2500 -760 to +4820
120Ω Nickel -80 to +260°C -800 to [phone] to +5000

Engineering Units x1

0.1°C 0.1°F

200 Nickel -60C to 250°C -600 to +2500 -760 to +4820

500 Nickel -60 to 250°C -600 to +2500 -760 to +4820

Table 3.4 Resistance Data Format

Resistance Input Range

Resistance 100mΩ 1 to 625Ω 10 to 6250
Resistance 10mΩ 1 to 327Ω 100 to 32700

Data Format

Engineering Units x1

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3-4 Module Data, Status, and Channel Configuration for DeviceNet

The module scales input data to the actual temperature values for the
selected RTD type per RTD standard. It expresses temperatures in 0.1
degree units, either degrees C or degrees F, depending on which
temperature scale is selected. For resistance inputs, the module expresses
resistance in 0.1

scale.

Negative temperatures are returned in 16-bit two’s complement binary
format. See Appendix B for a detailed explanation of two’s complement
binary numbers.

Ω units for the 100mΩ scale and in 0.01Ω units for the 10mΩ

Filter Frequency

The module supports filter selections corresponding to filter frequencies
of 10Hz, 25Hz, 50 Hz, 60 Hz, 100 Hz, 250 Hz, and 500 Hz. Your filter
frequency selection is determined by the desired range for the input type,
and the required effective resolution, which indicates the number of bits
in the input data that do not vary due to noise. Also consider the required
module update time when choosing a filter frequency. For example, the
10 Hz filter provides the greatest attenuation of 50 and 60 Hz noise and
the greatest resolution, but also provides the slowest response speed.

The choice that you make for filter frequency will affect:

• noise rejection characteristics for module input

• channel step response

• channel cutoff frequency

• effective resolution

• module update time

Effects of Filter Frequency on Noise Rejection

The filter frequency that you choose for the module determines the
amount of noise rejection for the inputs. A smaller filter frequency (e.g.
10Hz) provides the best noise rejection and increases effective resolution,
but also increases channel update time. A larger filter frequency (e.g. 500
Hz) provides lower noise rejection, but also decreases the channel update
time and effective resolution.

Publication 1790-UM002A-EN-P

When selecting a filter frequency, be sure to consider channel cutoff
frequency and channel step response to obtain acceptable noise rejection.
Choose a filter frequency so that your fastest-changing signal is below that
of the filter’s cutoff frequency.

Module Data, Status, and Channel Configuration for DeviceNet 3-5

Common mode noise rejection for the module is better than 110 dB at 50
Hz (50 Hz filter) and 60 Hz (60 Hz filter). The module performs well in
the presence of common mode noise. Improper earth ground can be a
source of common mode noise.

Channel Step Response

NOTE

Transducer power supply noise, transducer circuit noise,
and process variable irregularities can also be sources of
common mode noise.

Another module characteristic determined by filter frequency is channel
step response, as shown in the following table. The step response is the
time required for the analog input signal to reach 100 percent of its
expected final value, given a full-scale step change in the input signal.
Thus, if an input signal changes faster than the channel step response, a
portion of that signal will be attenuated by the channel filter. The channel
step response is calculated by a settling time of 3 x (1 / filter frequency).

Table 3.5 Filter Frequency vs. Channel Step Response

Filter Frequency Step Response

10 Hz 300 ms

25 Hz 120 ms

50 Hz 60 ms

60 Hz 50 ms

100 Hz 30 ms

250 Hz 12 ms

500 Hz 6 ms

Publication 1790-UM002A-EN-P

3-6 Module Data, Status, and Channel Configuration for DeviceNet

Channel Cutoff Frequency

The channel cutoff frequency (-3 dB) is the point on the input channel
frequency response curve where frequency components of the input
signal are passed with 3 dB of attenuation. The following table shows
cutoff frequencies for the supported filters.

Table 3.6 Filter Frequency vs. Channel Cutoff Frequency

Filter Frequency Channel Cutoff Frequency

10 Hz 2.62 Hz

25 Hz 6.55 Hz

50 Hz 13.1 Hz

60 Hz 15.7 Hz

100 Hz 26.2 Hz

250 Hz 65.5 Hz

500 Hz 131 Hz

All frequency components at or below the cutoff frequency are passed by
the digital filter with less than 3 dB of attenuation. All frequency
components above the cutoff frequency are increasingly attenuated, as
shown in the graphs below for several of the input filter frequencies.

NOTE

Channel cutoff frequency should not be confused with
channel update time. The cutoff frequency simply
determines how the digital filter attenuates frequency
components of the input signal.

Publication 1790-UM002A-EN-P

Module Data, Status, and Channel Configuration for DeviceNet 3-7

Frequency Response Graphs

Gain (dB)

Gain (dB)

–20

–40

–60

–80

-100

-120

-140

-160

-180

- 200

- 200

0

–20

–40

–60

–80

-100

-120

-140

-160

-180

0

2.62 Hz

0

0

1 5 .72 Hz

10 Hz Input Filter Frequency

–3 dB

10

20

60 Hz Input Filter Frequency

–3 dB

60

120

30

40

Frequency (Hz)

180

Frequency (Hz)

240

0

–20

–40

–60

–80

-100

-120

Gain (dB)

-140

-160

-180

50

60

- 200

13. 1 Hz

–3 dB

0

50

100

150

200

250

300

Frequency (Hz)

250 Hz Input Filter Frequency

50 Hz Input Filter Frequency

300

360

0

–20

–40

–60

–80

-100

Gain (dB)

-120

-140

-160

-180

- 200
0

65 .5 Hz

–3 dB

900

Frequency (Hz)

1300

1150750500250

500 Hz Input Filter Frequency

0

–20

–40

–60

–80

-100

-120

Gain (dB)

-140

-160

-180

- 200

131 Hz

–3 dB

2000

Frequency (Hz)

30000 250015001000500

43259

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3-8 Module Data, Status, and Channel Configuration for DeviceNet

Effective Resolution

Input Type Range 10 Hz 25 Hz 50/60 Hz 100 Hz 250 Hz 500 Hz

100 ohm Pt α=385 -200/850°C Sign + 14

200 ohm Pt α=385 -200/850°C Sign + 14

500 ohm Pt α=385 -200/650°C Sign + 13

100 ohm Pt α=3916 -200/640°C Sign + 13

200 ohm Pt α=3916 -200/640°C Sign + 13

500 ohm Pt α=3916 -200/640°C Sign + 13

100 ohm Nickel -60/250°C Sign + 12

The table below identifies the number of significant bits used to represent
the input data for each available filter frequency. The number of
significant bits is defined as the number of bits that will have little or no
jitter due to noise, and is used in defining the effective resolution.

Table 3.7 Input Effective Resolution Versus Input Filter Selection

bits 0.1°C

bits 0.1°C

bits 0.1°C

bits 0.1°C

bits 0.1°C

bits 0.1°C

bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 14
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 13
bits 0.2°C

Sign + 13
bits 0.2°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 13
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 11
bits 0.5°C

Sign + 11
bits 0.5°C

Sign + 11
bits 0.4°C

Sign + 11
bits 0.4°C

Sign + 11
bits 0.4°C

Sign + 11
bits 0.4°C

Sign + 11
bits 0.2°C

120 ohm Nickel -80/260°C Sign + 12

bits 0.1°C

200 ohm Nickel -60/250°C Sign + 12

bits 0.1°C

500 ohm Nickel -60/250°C Sign + 12

bits 0.1°C

Resistance 100mΩ 1/625 Ω Sign + 13

bits 0.1Ω

Resistance 100mΩ 1/327 Ω Sign + 15

bits 0.1Ω

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 13

bits 0.1Ω

Sign + 15

bits 0.1Ω

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 13

bits 0.1Ω

Sign + 15

bits 0.1Ω

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 13

bits 0.1Ω

Sign + 15

bits 0.1Ω

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 12
bits 0.1°C

Sign + 13

bits 0.1Ω

Sign + 13

bits 0.04Ω

Sign + 11
bits 0.2°C

Sign + 11
bits 0.2°C

Sign + 11
bits 0.2°C

Sign + 13

bits 0.4Ω

Sign + 11

bits 0.2Ω

Publication 1790-UM002A-EN-P

Module Data, Status, and Channel Configuration for DeviceNet 3-9

Determining Module Update Time

The module update time is defined as the time required for the module to
sample and convert the input signals. The module sequentially samples
the channels in a continuous loop. Module update time is dependent on
the number of input channels and the input filter selection.

The fastest update time occurs with the 500Hz filter enabled. The
following table shows update times for all filter frequencies.

Table 3.8 Module Update Time

Filter
Frequency

10 Hz 2.2 seconds

25 Hz 840 milliseconds

50 Hz 420 milliseconds

60 Hz 348 milliseconds

100 Hz 224 milliseconds

250 Hz 88 milliseconds

500 Hz 48 milliseconds

Module Update Time

DeviceNet RTD/ Resistance Module (1790D-4R0/T4R0)

Configuring 1790D-4R0/T4R0 RTD/resistance modules is as easy as
pointing and clicking. RSNetWorx™ lets you simply identify the network
and configure the I/O modules with easy-to-use Electronic Data Sheets
(EDS) files - just point to the field and click on your selection.

To obtain the EDS files you need to configure the modules, go to the
following website: http:/www.ab.com/networks/eds.

EDS files for blocks with matching catalog numbers (for D-Shell and
terminal block versions) are the same. Thus, on the website or in
RSNetWorx for DeviceNet, there may be only one catalog number listed
for both versions.

When using 3rd party configuration software, simply load the EDS files
into the software and follow the vendor’s instructions.

The following example takes you through configuring your RTD/
resistance module with RSNetWorx for DeviceNet, version 3.00 or later.

NOTE

Refer to Appendix C to configure the 1790P-T4R0
PROFIBUS module.

Publication 1790-UM002A-EN-P

3-10 Module Data, Status, and Channel Configuration for DeviceNet

Configure DeviceNet RTD/Resistance Modules Using RSNetWorx

Online Browse
Button

Following the steps below to configure 1790D-4R0/T4R0 RTD/resistance
modules.

1. Open RSNetWorx for DeviceNet.

2. Using the selections on the left of the window below, construct you

system. (If your network is up, just click on the Online Browse
button.)

Publication 1790-UM002A-EN-P

Module Data, Status, and Channel Configuration for DeviceNet 3-11

3. After setting up your system, double-click on the module you want to

configure. (If you are online, upload the configuration and existing
parameters from the module display.) A window similar to the
following appears.

Click the device
Parameters tab to
display the screen in
which you can set
parameters.

RTD/resistance modules will have parameters similar to the following.

If you see a lock next to
an entry, this indicates
that you cannot change
that parameter.

On this screen, you see all the parameters for the module. These include Autobaud,
RTD Input value, combined temperature units/filter frequency, module status and
Input RTD/resistance type.

Publication 1790-UM002A-EN-P

3-12 Module Data, Status, and Channel Configuration for DeviceNet

Module configuration parameters include Temperature Units/Notch
Filter frequency, RTD/resistance Input type and Autobaud.

Select the desired
temperature units (in
degrees C or F) and notch
filter frequency. ALL four
channels will be
configured identically.

Select the RTD/
resistance input type for
each channel from the
dropdown list.

Select to have Autobaud
either Enabled or
Disabled.

Publication 1790-UM002A-EN-P

Module Data, Status, and Channel Configuration for DeviceNet 3-13

n

Once module configuration is
complete, click either the
Download or Apply button
and click Yes for the popup
question.

Then click OK to close the
module properties window.

RTD/resistance module parameters may be monitored real time. The
most convenient way to monitor module parameters is to:

a. Click the Groups checkbox.

b. Close the No Group Specified folder

c. Open the I/O Input Values and I/O Input Status folders.

d. Click the Monitor button.

The module parameters are sequentially updated.

Check Groups

Click the Monitor butto
Open these
folders

Close this folder

Publication 1790-UM002A-EN-P

3-14 Module Data, Status, and Channel Configuration for DeviceNet

Chapter Summary

In this chapter, you learned how to setup and configure your module. See
Chapter 4 to learn how to troubleshoot using the module indicators.

Publication 1790-UM002A-EN-P

Chapter

4

Diagnostics and Troubleshooting

This chapter describes module troubleshooting, containing information
on:

• safety considerations when troubleshooting

• module vs. channel operation

• the module’s diagnostic features

• critical vs. non-critical errors

• module condition data

• contacting Rockwell Automation for assistance

Safety Considerations

Safety considerations are an important element of proper troubleshooting
procedures. Actively thinking about the safety of yourself and others, as
well as the condition of your equipment, is of primary importance.

The following sections describe several safety concerns you should be
aware of when troubleshooting your control system.

ATTENTION

ÿ

Never reach into a machine to actuate a switch because
unexpected motion can occur and cause injury.

Remove all electrical power at the main power disconnect
switches before checking electrical connections or inputs/
outputs causing machine motion.

Indicator Lights

When the green MOD and NET LED on the thermocouple module are
illuminated, it indicates that power is applied to the module, that it has
passed its internal tests and that the module is communicating on the
network.

Activating Devices When Troubleshooting

When troubleshooting, never reach into the machine to actuate a device.
Unexpected machine motion could occur.

1 Publication 1790-UM002A-EN-P

4-2 Diagnostics and Troubleshooting

Stand Clear of the Equipment

When troubleshooting any system problem, have all personnel remain
clear of the equipment. The problem could be intermittent, and sudden
unexpected machine motion could occur. Have someone ready to operate
an emergency stop switch in case it becomes necessary to shut off power.

Program Alteration

There are several possible causes of alteration to the user program,
including extreme environmental conditions, Electromagnetic Interference
(EMI), improper grounding, improper wiring connections, and
unauthorized tampering. If you suspect a program has been altered,
check it against a previously saved master program.

Safety Circuits

Circuits installed on the machine for safety reasons, like over-travel limit
switches, stop push buttons, and interlocks, should always be hard-wired
to the master control relay. These devices must be wired in series so that
when any one device opens, the master control relay is de-energized,
thereby removing power to the machine. Never alter these circuits to
defeat their function. Serious injury or machine damage could result.

Module Operation vs. Channel Operation

The module performs diagnostic operations at both the module level and
the channel level. Module-level operations include functions such as
power-up, configuration, and communication with a controller.

Channel-level operations describe channel related functions, such as data
conversion and over- or under-range detection.

Internal diagnostics are performed at both levels of operation. When
detected, module error conditions are indicated by the module status LED.
Channel over-range or under-range conditions are reported in the
module’s input data table.

Publication 1790-UM002A-EN-P

Diagnostics and Troubleshooting 4-3

Power-up Diagnostics

Power-up diagnostics includes module status and network status.

Module Status

At module power-up, a series of internal diagnostic tests are performed.
These diagnostic tests must be successfully completed. The following
table shows module status LED indictor operation.

Table 4.1 Module Status Power-up Diagnostics

1790D-4R0/T4R0, 1790P-T4R0
LED Indicator: Status: Description:

Module Status Solid Red Unrecoverable fault

Flashing Red Recoverable fault

Solid Green Normal operation - OK

Flashing Green Standby

Off No power

Network Status

The network status LED indicator shows the condition of the network
connection. The following tables show network status LED indicator
operation.

Table 4.2 Network Status Power-up Diagnostics for 1790D-4R0/T4R0)

1790D-4R0/T4R0
LED Indicator: Status: Description:

Network Status Solid Red Unrecoverable communication fault

Flashing Red Recoverable communication fault

Solid Green Communication path complete - OK

Flashing Green Communication path incomplete

Off Device not online or not powered

Table 4.3 Network Status Power-up Diagnostics for the 1790P-T4R0

1790P-4R0
LED Indicator: Status: Description:

Network Status Solid Green Communication path complete - OK

Flashing Green Communication path incomplete

Off No power or baud rate search

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4-4 Diagnostics and Troubleshooting

Channel Diagnostics

When an input channel is enabled, the module performs a diagnostic
check to see that the channel has been properly configured. In addition,
the channel is tested on every scan for configuration errors, over-range
and under-range, and broken input conditions.

Non-critical module errors are typically recoverable. Channel errors
(over-range or under-range errors) are non-critical. Non-critical error
conditions are indicated in the module input data table.

Out-of-Range Detection

When the input signal data received at the channel word is out of the
defined operating range, an over-range or under-range error is indicated
in input data word 4.

Possible causes for an out-of-range condition include:

• The temperature is too hot or too cold for the RTD being used.

• The wrong RTD is being used for the input type selected, or for the

configuration that you have programmed.

• The input device is faulty.

• The signal input from the input device is beyond the scaling range.

Open-Wire Detection

The module performs an open-circuit input test on all channels on each
scan. Whenever an open-circuit condition occurs, the overrange input bit
for that channel is set in input data word 4.

Possible causes of a broken input condition include:

• the input device is broken

• a wire is loose or cut

• the input device is not installed on the configured channel

• an RTD is internally shorted

• an RTD is not installed correctly

Module Error Definition Table

RTD/resistance module errors are expressed on a channel basis in input
read word 4. The structure of the status data is shown in the following
table.

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Diagnostics and Troubleshooting 4-5

Table 4.4 Word Bit Position

Word Bit Description

1514131211109876543210

4 Not Used S11 S10 S9 S8 Not Used S3 S2 S1 S0

Table 4.5 Word/Bit Description

Word Decimal Bit Description

Bits 00-03 Underrange for individual channels. Bit 00 corresponds to input

channel 0, bit 01 corresponds to input channel 1 and so on.
When set (1), the input signal is below the input channel’s

minimum range

Read Word 4

Bits 04-07 Not used: Set to 0

Bit 08-11 Overrange for individual channels. Bit 08 corresponds to input

channel 0, bit 09 corresponds to input channel 1 and so on.
When set (1), the input signal is above the input channel’s

maximum range, or open RTD is detected

Bit 12-15 Not used: Set to 0

Channel LED Indicator Operation

Individual channel LED indicator operation is shown in the following
table.

Table 4.6 Individual Channel LEDs Indicator

I/O Channel LED Status Indicator
Status: Description

Flashing Green/Red Power up

Off Off line

Red On line and no field power

Red DeviceNet connection and no field power

Flashing Red Field power and open wire

Green Field power and valid input

Flashing Red Input over range, open input

Flashing Red Input under range

Flashing Red Recoverable fault

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4-6 Diagnostics and Troubleshooting

Contacting Rockwell Automation

Chapter Summary

If you need to contact Rockwell Automation for assistance, please have
the following information available when you call:

• a clear statement of the problem, including a description of what the

system is actually doing. Note the LED state; also note input and
output image words for the module.

• a list of remedies you have already tried

• processor type and firmware number (See the label on the processor)

• hardware types in the system, including all I/O modules

• fault code if the processor is faulted

In this chapter, you learned how to perform diagnostic and
troubleshooting on the 1790D/4R0/T4R0 and 1790P-TR40 RTD/resistance
modules. See the appendixes for module specifications, binary number
information, and module configuration for PROFIBUS.

Publication 1790-UM002A-EN-P

Environmental Specifications

Appendix

Specifications

Environmental Specifications

Operating Temperature 0 to 55°C (32 to 131°F)

IEC 60068-2-1 (Test Ad, Operating Cold),
IEC 60068-2-2 (Test Bd, Operating Dry Heat),
IEC 60068-2-14 (Test Nb, Operating Thermal Shock)

Storage Temperature -40 to 85°C (-40 to 185°F)

IEC 60068-2-1 (Test Ab, Un-packaged Non-operating Cold),
IEC 60068-2-2 (Test Bb, Un-packaged Non-operating Dry Heat),
IEC 60068-2-14 (Test Na, Un-packaged Non-operating Thermal Shock)

Relative Humidity 5-90% non-condensing

IEC 60068-2-30 (Test Db, Un-packaged Non-operating)

Operating Altitude 2000m

Vibration I2g @ 10-500Hz

EC60068-2-6 (Test Fc, Operating)

Shock: Operating

Non-operating

Emissions Group 1, Class A

ESD Immunity 8kV air discharges

Radiated RF Immunity 10V/m with 1kHz sine-wave 80%AM from 80MHz to 1000MHz

EFT/B Immunity +

Surge Transient
Immunity

Conducted RF Immunity 10Vrms with 1kHz sine-wave 80%AM from 150kHzto 80MHz

Enclosure Type Rating None (open style)

Mounting DIN rail or screw

Dimensions 52 x 104 x 42mm (2.03 x 4.07 x 1.64in)

Weight 0.3lb (0.1kg)

I0g
30g

IEC60068-2-27 Test Ea, (Unpackaged Shock)

CISPR 11

IEC 61000-4-2

10V/m with 200Hz 50% Pulse 100%AM @ 900Mhz
IEC 61000-4-3

1kV @ 5kHz on power ports

+2kV @ 5kHz on signal ports

2kV @ 5kHz on communications ports

+
IEC 61000-4-4

1kV line-line(DM) and +2kV line-earth(CM) on power ports

+

1kV line-line(DM) and +2kV line-earth(CM) on signal ports

+

2kV line-earth(CM) on shielded ports

+
IEC 61000-4-5

IEC 61000-4-6

A

1 Publication 1790-UM002A-EN-P

A-2 Specifications

DeviceNet Specifications

PROFIBUS DP Specifications

Specification Value

Network protocol I/O Slave messaging:

- Poll command

- Bit Strobe command

- Cyclic command

- COS command

Network length 500 meters maximum @ 125Kbps

100 meters maximum @ 500Kbps

Indicators 1 red/green module status

1 red/green network status

Number of nodes 64 maximum - rotary switch type node address setting

Communication rate 125Kbps, 250Kbps, 500Kbps - auto baud rate selection

Isolation Type test 1250Vac rms for 60 seconds between field power and

DeviceNet (I/O to logic)

Wiring Refer to publication DN-6.7.2

PROFIBUS DP Specifications

Network Protocol PROFIBUS-DP (EN50170)

Communication of the slave with a Class 1 master

Communication of the slave with a Class 2 master
Redundancy Not supported
Repeater Control Signal RS485 signal
Implementation Type DPC31
Freeze Mode Supported
Sync Mode Supported
Auto Baud Rate Supported
Fail Safe Mode Supported
Station Type Slave
FMS Support Not supported
Indicators 1 red/green module status

1 red/green network status
Number of nodes 100 maximum - rotary switch type node address setting (0-99)
Network Length/

Communication rate

Isolation Type test 1250Vac rms for 60 seconds between field power and

9.6Kbps @ 1000m (3280ft)

19.2Kbps @ 1000m (3280ft)

45.45Kbps @ 1000m (3280 ft)

93.75Kbps @ 1000m (3280ft)

187.5Kbps @ 1000m (3280ft)

500Kbps @ 400m (1312ft)

1.5mbps @ 200m (656ft)

3mbps @ 100m (328ft)

6mbps @ 100m (328ft)

12mbps @ 100m (328ft)

PROFIBUS (I/O to logic)

Publication 1790-UM002A-EN-P

General Specifications

Specifications A-3

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Wiring Category

Product Certifications
(when product or
packaging is marked)

1

2

c-UL-us UL Listed for Class I, Division 2 Group A,B,C,D Hazardous
Locations, certified for U.S. and Canada

CE

2

European Union 89/336/EEC EMC Directive, compliant with:
EN 50081-2; Industrial Emissions
EN 50082-2; Industrial Immunity
EN61326; Meas./Control/Lab., Industrial Requirements
EN 61000-6-2; Industrial Immunity

2

C-Tick

Australian Radiocommunications Act, compliant with:
AS/NZS 2064; Industrial Emissions

ODVA ODVA conformance tested to ODVA DeviceNet
specifications

DeviceNet Power Supply voltage - 24V dc nominal

Voltage range - 11-28.8V dc
Power dissipation - 1.2W maximum @ 28.8V dc

PROFIBUS Power Supply voltage - 24V dc nominal

Voltage range - 19.2-28.8V dc
Power dissipation - 2W maximum @ 28.8V dc

Field Power Supply Voltage - 24Vdc nominal

Voltage Range - 21.6-26.4V dc (+

10%)

Power Dissipation - 1.5W maximum @ 26.4V dc

Isolation I/O to logic: photocoupler isolation

Isolation voltage: Type Test 1250V ac rms for 60 seconds
DeviceNet to logic: non-isolated
Field power: non-isolated

Indicators 4 red/green I/O status

Wiring
1790D-4R0
1790D-T4R0

1

Refer to publication 1770-4.1,

2

See the Product Certification link at www.ab.com for Declarations of Conformity, Certificates and other certification details.

37-pin D-Shell connector
Terminal block connector screw torque: 7 inch pounds maximum

Programmable Controller Wiring and Grounding Guidelines.

IMPORTANT

This module does not support any expansion modules.

Publication 1790-UM002A-EN-P

A-4 Specifications

RTD/Resistance Specifications

RTD/resistance Specifications

Inputs per module 4 channel, RTD/Resistance Input
Input Range 1-625
Sensors Supported Sensor Type Degree Counts Resolution

Resistance 100mΩ 1 to 625Ω 10 to 6250 100mΩ
Resistance 10mΩ 1 to 327Ω 100 to 32700 10mΩ
100ohm Pt/α =0.00385 -200 to +850°C -2000 to +8500 0.1°C
200ohm Pt/α =0.00385 -200 to +850°C -2000 to +8500 0.1°C
500ohm Pt/α =0.00385 -200 to +650°C -2000 to +6500 0.1°C
100ohm Pt/α =0.003916 -200 to +640°C -2000 to +6400 0.1°C
200ohm Pt/α =0.003916 -200 to +640°C -2000 to +6400 0.1°C
500ohm Pt/α =0.003916 -200 to +640°C -2000 to +6400 0.1°C

100ohm Nickel -60 to 250°C -600 to 2500 0.1°C
120ohm Nickel -80 to 260°C -800 to 2600 0.1°C
200ohm Nickel -60 to 250°C -600 to 2500 0.1°C
500ohm Nickel -60 to 250°C -600 to 2500 0.1°C

Resolution 16 bits across 625ohms, 0.1°C/bit or 0.1°F/bit (RTD Sensors)

20bit Sigma-Delta modulation converter
Data Format 16 bit Integer (2’s compliment)
Module Scan Time 8ms/channel @ Notch Filter = 60Hz
Overall accuracy 0.2% Full scale @ 0°C-55°C
Settable Notch Filter 10Hz (default), 25Hz, 50Hz, 60Hz, 100Hz, 250Hz, 500Hz
Open Wire Detection Out of range, open wiring
Excitation Current 1mA
Input Impedance 5M ohm

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Appendix

B

Two’s Complement Binary Numbers

The processor memory stores 16-bit binary numbers. Two’s complement
binary is used when performing mathematical calculations internal to the
processor. Analog input values from the RTD/resistance module are
returned to the processor in 16-bit two’s complement binary format. For
positive numbers, the binary notation and two’s complement binary
notation are identical.

As indicated in the figure on the next page, each position in the number

0

has a decimal value, beginning at the right with 2

15

with 2

. Each position can be 0 or 1 in the processor memory. A 0
indicates a value of 0; a 1 indicates the decimal value of the position. The
equivalent decimal value of the binary number is the sum of the position
values.

and ending at the left

Positive Decimal Values

The far left position is always 0 for positive values. As indicated in the
figure below, this limits the maximum positive decimal value to 32767 (all
positions are 1 except the far left position). For example:

0000 1001 0000 1110 = 2

0010 0011 0010 1000 = 2

1 x 2 = 16384

0111111111111111

15

0 x 2 = 0

11+28+23+22+21

13+29+28+25+23

14

13

1 x 2 = 8192

12

1 x 2 = 4096

11

1 x 2 = 2048

1 x 2 = 1024

This position is always 0 for positive numbers.

= 2048+256+8+4+2 = 2318

= 8192+512+256+32+8 = 9000

10

9

1 x 2 = 512

8

1 x 2 = 256

7

1 x 2 = 128

6

1 x 2 = 64

5

1 x 2 = 32

4

1 x 2 = 16

3

1 x 2 = 8

1 x 2 = 4

2

1

1 x 2 = 2

0

1 x 2 = 1

43260

16384

8192
4096
2048
1024

512
256
128

64
32
16

8
4
2
1

32767

1 Publication 1790-UM002A-EN-P

B-2 Two’s Complement Binary Numbers

14

Negative Decimal Values

In two’s complement notation, the far left position is always 1 for negative
values. The equivalent decimal value of the binary number is obtained by
subtracting the value of the far left position, 32768, from the sum of the
values of the other positions. In the figure below (all positions are 1), the
value is 32767 - 32768 = -1. For example:

1111 1000 0010 0011 = (2

14+213+212+211+25+21+20

) - 215 =

(16384+8192+4096+2048+32+2+1) - 32768 = 30755 - 32768 = -2013

1 x 2 = 16384

13

1 x 2 = 8192

12

1 x 2 = 4096

11

1 x 2 = 2048

10

1 x 2 = 1024

9

1 x 2 = 512

8

1 x 2 = 256

7

1 x 2 = 128

6

1 x 2 = 64

5

1 x 2 = 32

4

1 x 2 = 16

3

1 x 2 = 8

2

1 x 2 = 4

1 x 2 = 2

1111111111111111

15

1 x 2 = 32768

This position is always 1 for negative numbers.

1

0

1 x 2 = 1

16384

8192
4096
2048
1024

512
256
128

64
32
16

8
4
2
1

32767

43261

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Appendix

C

Module Configuration for PROFIBUS

After installation of the RTD/resistance module, you must configure it for
operation, usually by using the programming software compatible with
the controller or scanner. This appendix includes PROFIBUS configuration
information.

Chapter 3 contains detailed information on module parameters and
performance. While configuring your RTD/resistance module for
operation on PROFIBUS, refer to Chapter 3 for the following information:

• module memory map

• input data file

• data format

• filter frequencies

Configure PROFIBUS RTD/Resistance Modules (1790P-T4R0)

Configure RTD/
Resistance Modules
Using the SST
PROFIBUS Configuration

• channel step response

• channel cutoff frequency

• effective resolution

• module update time

Configuration of the 1790P-T4R0 RTD/resistance modules is accomplished
through PROFIBUS configuration software with easy-to-use-GSD files. To
obtain the GSD files you need to configure the module, access the
following website.

http://www.ab.com/networks/gsd.

The example in this chapter shows you how to configure the RTD/
resistance module with the SST PROFIBUS Configuration tool.

The configuration example outlined in this section is written for an
experienced PROFIBUS user. Refer to your scanner and network
documentation for more complete details.

Open your SST PROFIBUS Configuration tool.

To o l

IMPORTANT

1 Publication 1790-UM002A-EN-P

If online, make sure the processor is in Program mode.

C-2 Module Configuration for PROFIBUS

If it’s not already installed, add the RTD/resistance module GSD file from
the dropdown menu. Access:

1. Library>Add GSD.

2. Click File>New.

If the PROFIBUS devices pane is closed, choose:

3. View>Library to open the pane.

If the on-line Browse pane is closed, choose:

4. View>On-line to open the pane.

You should now be ready to set up your system.

5. Expand the Master and Slaves folders in the PROFIBUS Device pane.

Expand Master
folder

Expand Slave
folder

Choose Master for your
network, drag and drop to
Network pane.

6. Choose the Master device for your network, drag and drop the device

to the Network pane.

From the following window:

Choose the
Master Station
number

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Module Configuration for PROFIBUS C-3

Choose the
Master
communication
parameters

You can add modules to the network by:

1. Selecting slaves from the PROFIBUS Device pane

2. Dragging and dropping them to the network pane
Or, if online, by performing a search for slaves
See the following screens for an outline of this procedure.

First, configure the network search properties.
Second, search for slave modules.

Publication 1790-UM002A-EN-P

C-4 Module Configuration for PROFIBUS

Highlight the slave, right click the mouse and
select GSD Files>1790-T4R0.gsd

7. Highlight the slave from the Online Browse pane and drag and drop it

to the Network pane.

The slave station number should be set. (If you dragged and dropped
from the PROFIBUS Device pane, you must set the station number.)

Station number
should be set

Highlight and drag and drop the slave device to
the Network pane

8. Click the SLC address tab for data size information and to set the I/O

data type. For this example, we choose I Type (Input Image in the
processor).

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Module Configuration for PROFIBUS C-5

The 1790P-T4R0
module produces 5
words of data.

The produced 5
words will appear
in the processor
input data table.

9. Click the Ext. Prms tab.

This is where the parameters that can be set for the slave RTD/
resistance module are configured.

On this screen, you
see all the
parameters for the
module. These
include watchdog
time, temperature
units, filter
frequency, and
input RTD/
resistance type.

Module configuration parameters include watchdog time base,
temperature units, filter frequency, and input RTD/resistance type.

Select the watchdog
time base (10 ms or
1 ms).

Publication 1790-UM002A-EN-P

C-6 Module Configuration for PROFIBUS

Select the
temperature units
(degrees C or F). All
four channels will be
configured
identically.

Select the filter cutoff
frequency desired. All
four channels will be
configured identically.

Save the Configuration

Select the RTD/
resistance input type
for each channel
from the dropdown
list.

10. When configuration is complete, click the OK button to close the

module properties screen.

To close the configuration:

1. Choose File>Save As.

2. Specify a file name and location to save your configuration.

3. Click Save.

This saves your project as a .pbc (PROFIBUS configuration file).

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Module Configuration for PROFIBUS C-7

Download the Configuration

To download the configuration:

1. Verify that the processor is in Program Mode.

2. Make sure the serial communication cable is connected between the

PC comm port and the scanner serial port.

3. Highlight Master in the Network pane.

4. Right click to select Connect from the menu. (Or, choose
Edit>Connect).

Highlight the Master and then right
click to select Connect.

You may be prompted with a message indicating a configuration
mismatch between what is in the scanner and your current PROFIBUS
project. In this case, select Yes to retain your configuration.

Any configuration mismatches display for the Master status.

Publication 1790-UM002A-EN-P

C-8 Module Configuration for PROFIBUS

5. Load the configuration to the Master through one of the following

methods.

• Right click on the Master and select Load Configuration from the

menu.

Or,

• Select the Load configuration icon in the toolbar.

If the scanner is online, the following message displays:

Card is online. Do you want to load configuration.

• Select Yes to load your new configuration.

You may receive this message:

This is only a warning that if your Min Cycle Time is not twice as long
as the Scan Time then you may lose serial communications. This
message can usually be ignored unless you require online monitoring.

The Master status now changes to the Configured Program Mode.

Publication 1790-UM002A-EN-P

Your scanner is now configured and ready.

6. Turn the processor to Run mode.

Module Configuration for PROFIBUS C-9

The Net LED on the RTD/resistance module should turn solid green as
should the Comm LED on the scanner. The connection should report
OK.

The master should now display:

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C-10 Module Configuration for PROFIBUS

Summary

This appendix illustrated how to configure your PROFIBUS RTD/
resistance module with the SST PROFIBUS Configuration tool.

For more information, consult your PROFIBUS network documentation,
PROFIBUS scanner documentation and network configuration tool
documentation.

Publication 1790-UM002A-EN-P

Glossary

The following terms and abbreviations are used throughout this manual.
For definitions of terms not listed here refer to Allen-Bradley’s Industrial
Automation Glossary, Publication AG-7.1.

A/D Converter– Refers to the analog to digital converter inherent to the
module. The converter produces a digital value whose magnitude is
proportional to the magnitude of an analog input signal.

attenuation – The reduction in the magnitude of a signal as it passes
through a system.

channel – Refers to input interfaces available on the module’s terminal
block. Each channel is configured for connection to a thermocouple or
millivolt input device, and has its own data and diagnostic status words.

channel update time – The time required for the module to sample and
convert the input signals of one enabled input channel and update the
channel data word.

common mode rejection – For analog inputs, the maximum level to
which a common mode input voltage appears in the numerical value read
by the processor, expressed in dB.

common mode rejection ratio (CMMR) – The ratio of a device’s
differential voltage gain to common mode voltage gain. Expressed in dB,
CMRR is a comparative measure of a device’s ability to reject interference
caused by a voltage common to its input terminals relative to ground.
CMRR=20 Log

common mode voltage – The voltage difference between the negative
terminal and analog common during normal differential operation.

common mode voltage range – The largest voltage difference allowed
between either the positive or negative terminal and analog common
during normal differential operation.

cut-off frequency – The frequency at which the input signal is
attenuated 3 dB by a digital filter. Frequency components of the input
signal that are below the cut-off frequency are passed with under 3 dB of
attenuation for low-pass filters.

data word – A 16-bit integer that represents the value of the input
channel. The channel data word is valid only when the channel is
enabled and there are no channel errors. When the channel is disabled
the channel data word is cleared (0).

10 (V1/V2)

dB – (decibel) A logarithmic measure of the ratio of two signal levels.

digital filter – A low-pass filter incorporated into the A/D converter. The

digital filter provides very steep roll-off above it’s cut-off frequency, which
provides high frequency noise rejection.

1 Publication 1790-UM002A-EN-P

G-2

effective resolution – The number of bits in a channel configuration
word that do not vary due to noise.

excitation current – A user-selectable current that the module sends
through the input device to produce an analog signal that the module can
process and convert to temperature (RTD) or resistance in ohms
(resistance device).

filter – A device that passes a signal or range of signals and eliminates all
others.

filter frequency – The user-selectable frequency for a digital filter.

full-scale – The magnitude of input over which normal operation is

permitted.

full-scale range – The difference between the maximum and minimum
specified analog input values for a device.

input data scaling – Data scaling that depends on the data format
selected for a channel configuration word. Scaling is selected to fit the
temperature or voltage resolution for your application.

input image – The input from the module to the controller. The input
image contains the module data words and status bits.

linearity error – Any deviation of the converted input or actual output
from a straight line of values representing the ideal analog input. An
analog input is composed of a series of input values corresponding to
digital codes. For an ideal analog input, the values lie in a straight line
spaced by inputs corresponding to 1 LSB. Linearity is expressed in percent
full-scale input. See the variation from the straight line due to linearity
error (exaggerated) in the example below.

Actual Transfer
Function

Ideal Transfer

43262

LSB – Least significant bit. The LSB represents the smallest value within a
string of bits. For analog modules, 16-bit, two’s complement binary codes
are used in the I/O image. For analog inputs, the LSB is defined as the
rightmost bit of the 16-bit field (bit 0). The weight of the LSB value is
defined as the full-scale range divided by the resolution.

Publication 1790-UM002A-EN-P

module scan time – same as module update time

G-3

module update time – The time required for the module to sample and
convert the input signals of all enabled input channels and make the
resulting data values available to the processor.

multiplexer – An switching system that allows several signals to share a
common A/D converter.

normal mode rejection – (differential mode rejection) A logarithmic
measure, in dB, of a device’s ability to reject noise signals between or
among circuit signal conductors. The measurement does not apply to
noise signals between the equipment grounding conductor or signal
reference structure and the signal conductors.

number of significant bits – The power of two that represents the total
number of completely different digital codes to which an analog signal
can be converted or from which it can be generated.

overall accuracy – The worst-case deviation of the digital representation
of the input signal from the ideal over the full input range is the overall
accuracy. Overall accuracy is expressed in percent of full scale.

repeatability – The closeness of agreement among repeated
measurements of the same variable under the same conditions.

resolution – The smallest detectable change in a measurement, typically
expressed in engineering units (e.g. 1°C) or as a number of bits. For
example a 12-bit system has 4096 possible output states. It can therefore
measure 1 part in 4096.

RTD – Resistance temperature detector. A temperature-sensing device that
consists of a temperature-sensing element connected by two, three, or
four lead wires that provide input to the module. The RTD uses the basic
concept that the electrical resistances of metals increase with temperature.
When a small current is applied to the RTD, it creates voltage that varies
with temperature. The module processes and converts this voltage into a
temperature value.

sampling time – The time required by the A/D converter to sample an
input channel.

step response time – The time required for the channel data word signal
to reach a specified percentage of its expected final value, given a
full-scale step change in the input signal.

update time – see “module update time”

Publication 1790-UM002A-EN-P

G-4

Notes:

Publication 1790-UM002A-EN-P

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Pub. Title/Type CompactBlock LDX RTD/Resistance Input Module

Cat. No. 1790D-(T)4R0,

1790P-T4R0

Pub. No. 1790-UM002A-EN-P Pub. Date May 2002 Part No. 957657-66

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Index

Numbers

1790D-4R0

general description 1-1
hardware features 1-3
power requirements 2-2

1790D-T4R0

general description 1-1
hardware features 1-3
power requirements 2-2

1790P-T4R0

connecting power 2-11
general description 1-1
hardware features 1-4
power requirements 2-2

A

A/D

definition G-1

A/D converter 1-5
abbreviations G-1
activating devices when

troubleshooting 4-1
addressing 3-1
attenuation 3-6

definition G-1

B

base block

mounting 2-7

broken input

detection 4-4

bus interface 1-4

C

channel 1-5

definition G-1

channel configuration for DeviceNet 3-1
channel cutoff frequency 3-4, 3-6
channel diagnostics 4-3

module error definition table 4-4
open-wire detection 4-4
out-of-range detection 4-4

channel LED indicator operation 4-5
channel status LED 1-4

channel step response 3-4, 3-5
channel update time 3-6

definition G-1

circuit board

protecting 2-6

CMRR. See common mode rejection ratio
comments about manual 3
common mode 3-5
common mode rejection

definition G-1

common mode rejection ratio

definition G-1

common mode voltage

definition G-1

common mode voltage range

definition G-1

configuration 3-1
configuration for PROFIBUS

RTD/resistance modules C-1

using SST tool C-1

configure

channel cutoff frequency 3-6
channel step response 3-5
data format 3-3
determining module update time 3-9
DeviceNet RTD/resistance module 3-9
effective resolution 3-8
filter frequency 3-4
input data file 3-2
input image file data 3-1
module memory map 3-1

connecting

DeviceNet cable 2-9
power to PROFIBUS block 2-11
PROFIBUS DP connector 2-10

connections

excitation 1-5
return 1-5
sense 1-5

cut-off frequency

definition G-1

D

data configuration for DeviceNet 3-1
data format 3-3

Publication 1790-UM002A-EN-P - May 2002

2 Index

data word

definition G-1

dB

definition G-1

decibel. See dB.
definition of terms G-1
determining module update time 3-9
DeviceNet cable

connecting 2-9

DeviceNet RTD resistance module 3-9

configure using RSNetWorx 3-10

DeviceNet specifications A-2
diagnostic features

general 1-4

diagnostics and troubleshooting 4-1

channel diagnostics 4-3
module operation vs channel operation

4-2
power-up diagnostics 4-3
safety considerations 4-1

diagnostics and troubleshootings

channel LED indicator operation 4-5

differential mode rejection. See normal

mode rejection.

digital filter

definition G-1

DIN rail mounting 2-8

E

effective resolution 3-8

definition G-2
number of significant bits 3-8

electrical noise 2-5
EMC Directive 2-1
environmental specifications A-1
excitation connections 1-5
excitation current 1-5

definition G-2

F

fault condition

at power-up 1-4

field wiring connections 2-12
filter

definition G-2

filter frequency 3-4, 3-6, 3-8

and channel cutoff frequency 3-6
and channel step response 3-5

and noise rejection 3-4
definition G-2

frequency response graphs 3-7
frequency. See filter frequency.
full-scale

definition G-2

full-scale range

definition G-2

G

general diagnostic features 1-4
general specifications A-3
grounding

installation

grounding 2-12

H

hardware features 1-3

general diagnostic features 1-4

hazardous location considerations 2-3
heat considerations 2-5

I

important user information 2
imput image file data

accessing 3-1

indicator lights 4-1
input data file 3-2

input data values 3-2
over-range flag bits 3-3
under-range flag bits 3-2

input data scaling

definition G-2

input data values 3-2
input image

definition G-2

installation

getting started 2-1
heat and noise considerations 2-5

installation and wiring 2-1

before you begin 2-1
field wiring connections 2-12

RTD wiring 2-13
system wiring guidelines 2-12
wiring resistance devices (potenti-

ometers) 2-16
wiring RTDs 2-15
wiring terminal blocks 2-18

Publication 1790-UM002A-EN-P - May 2002

Index 3

wiring the modules 2-14

general considerations 2-2

set station address (PROFIBUS) 2-7
hazardous location considerations

2-3
installing CompactBlock LDX I/O 2-6
protecting circuit board 2-6
selecting a location 2-5
set node address (DeviceNet) 2-6

mounting 2-7

base block 2-7
connecting DeviceNet cable 2-9
connecting power to PROFIBUS block

2-11
connecting PROFIBUS DP connector

2-10
DIN rail mounting 2-8
panel mounting 2-7

power requirements 2-2

installing CompactBlock LDX I/O 2-6

L

LED 4-1
linearity error

definition G-2

low voltage directive 2-1
LSB

definition G-2

M

module error definition table 4-4
module memory map 3-1
module operation

DeviceNet Example 1-5

module operation vs channel operation

4-2

module scan time

definition G-2

module status 4-3
module update time 3-9

definition G-3

mounting

DIN rail 2-8
panel 2-7

multiplexer

definition G-3

multiplexing 1-5

N

negative decimal values B-2
network status 4-3
noise 3-5
noise rejection 3-4
normal mode rejection

definition G-3

number of significant bits 3-8

definition G-3

O

open-wire detection 4-4
operation

system 1-4

out-of range detection 4-4
overall accuracy

definition G-3

over-range flag bits 3-3
overview 1-1

general description 1-1

resister device compatibility 1-3
RTD compatibility 1-2

P

panel mounting 2-7
positive decimal values B-1
potentiometers

wiring 2-16

power requirements 2-2

1790D-4R0 2-2
1790D-T4R0 2-2
1790P-T4R0 2-2

power-up diagnostics 4-3

module status 4-3
network status 4-3

power-up sequence 1-4
PROFIBUS configuration C-1

downloading C-6
RTD/resistance module C-1
saving C-6
using SST configuration tool C-1

PROFIBUS DP connector

connecting 2-10

PROFIBUS DP specifications A-2
PROFIBUS RTD/resistance module

configuration C-1
program alteration 4-2
programming software 3-1

Publication 1790-UM002A-EN-P - May 2002

4 Index

protecting circuit board 2-6

R

register

configuration 3-1

resistance devices

wiring 2-16

resister device compatibility 1-3
resolution

definition G-3

return connections 1-5
Rockwell Automation support 3
RTD

definition G-3
specifications 1-2

RTD compatibility 1-2
RTD wiring 2-13
RTD/Resistance specifications A-4

S

safety circuits 4-2
safety considerations 4-1

activating devices when troubleshooting

4-1
indicator lights 4-1
program alteration 4-2
safety circuits 4-2
stand clear of equipment 4-2

sampling time

definition G-3

scan time G-2
selecting a location 2-5
sense connections 1-5
set node address (1790D-4R0/T4R0) 2-6
set station address (PROFIBUS) 2-7
specifications 1-2, A-1

DeviceNet A-2
environmental A-1
general A-3
PROFIBUS DP A-2
RTD/resistance A-4

SST PROFIBUS configuration tool C-1
start-up instructions 2-1
status configuration for DeviceNet 3-1
step response time

definition G-3

support 3

contacting Rockwell Automation 4-5

system operation 1-4
system overview 1-4

module operation

DeviceNet Example 1-5

system operation 1-4

system wiring guidelines 2-12

T

terminal blocks

wiring 2-18

terminal screw torque 2-14
troubleshooting

safety considerations 4-1

two’s complement binary numbers B-1

negative decimal values B-2
positive decimal values B-1

U

under-range flag bits 3-2
update time. See channel update time.
update time. See module update time.

W

wire size 2-14
wiring 2-1

guidelines 2-12
module 2-14
modules 2-14
resistance devices (potentiometers) 2-16
routing considerations 2-5
RTD considerations 2-13
RTDs 2-15
terminal blocks 2-18

Publication 1790-UM002A-EN-P - May 2002

Publication 1790-UM002A-EN-P - May 2002 11 PN 957657-66

Copyright © 2002 Rockwell Automation. A ll rights reserved. Printed in the U.S.A.