Allen-Bradley MicroLogix 1200 RTD/Resistance User manual

Publication 1762-IN014B-EN-P - July 2013
Installation Instructions
MicroLogix 1200 RTD/Resistance Input Module
Catalog Number 1762-IR4
Topic Page
Module Overview 2
Description 2
Module Installation 3
System Assembly 4
Mounting 4
Field Wiring Connections 7
I/O Memory Mapping 15
Specifications 19
North American Hazardous Location Approval 22
Additional Resources 23

2MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
Module Overview
The 1762-IR4 module receives and stores digitally converted analog data from RTDs or other
resistance inputs, such as potentiometers. The module supports connections from any
combination of up to 4 RTDs or other resistance inputs. See the input specifications on page 20
for supported RTD and resistance types, their associated temperature ranges, and the analog
input signal ranges that each channel supports. Each of the 4 input channels is individually
configurable for a specific input device and provides open- or short-circuit and over- or
under-range indication.
Description
Item Description Item Description
1a upper panel mounting tab 5bus connector cover
1b lower panel mounting tab 6flat ribbon cable with bus connector (female)
2power diagnostic LED 7terminal block
3module door with terminal identification
label 8DIN rail latch
4bus connector with male pins 9pull loop
9
3
5
2
1b
1a
7
6
4
8
6
1a
1b
2

MicroLogix 1200 RTD/Resistance Input Module 3
Publication 1762-IN014B-EN-P - July 2013
Module Installation
1762 I/O is suitable for use in an industrial environment when installed in accordance with these
instructions. Specifically, this equipment is intended for use in clean, dry environments
(Pollution degree 2(1)) and to circuits not exceeding Over Voltage Category II(2) (IEC
60664-1).(3)
Prevent Electrostatic Discharge
Remove Power
(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.
ATTENTION
Electrostatic discharge can damage integrated circuits or semiconductors
if you touch bus connector pins. Follow these guidelines when you handle
the module:
•Touch a grounded object to discharge static potential.
•Wear an approved wrist-strap grounding device.
•Do not touch the bus connector or connector pins.
•Do not touch circuit components inside the module.
•If available, use a static-safe work station.
•When not in use, keep the module in its static-shield box.
ATTENTION
Remove power before removing or installing this module. When you
remove or install a module with power applied, an electrical arc may occur.
An electrical arc can cause personal injury or property damage by:
•sending an erroneous signal to your system’s field devices, causing
unintended machine motion
•causing an explosion in a hazardous environment
•causing permanent damage to the module’s circuitry
Electrical arcing causes excessive wear to contacts on both the module and
its mating connector. Worn contacts may create electrical resistance.

4MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
System Assembly
The expansion I/O module is attached to the controller or another I/O module by means of a
ribbon cable after mounting as shown below.
Mounting
TIP
Use the pull loop on the connector to disconnect modules. Do not pull
on the ribbon cable.
WARNING
EXPLOSION HAZARD
•In Class I, Division 2 applications, the bus connector must be fully
seated and the bus connector cover must be snapped in place.
•In Class I, Division 2 applications, all modules must be mounted in
direct contact with each other as shown on page 5. If DIN rail
mounting is used, an end stop must be installed ahead of the
controller and after the last 1762 I/O module.
ATTENTION
Do not remove protective debris strip until after the module and all other
equipment near the module is mounted and wiring is complete. Once
wiring is complete and the module is free of debris, carefully the remove
protective debris strip. Failure to remove the strip before operating can
cause overheating.

MicroLogix 1200 RTD/Resistance Input Module 5
Publication 1762-IN014B-EN-P - July 2013
Minimum Spacing
Maintain spacing from enclosure
walls, wireways, adjacent
equipment, etc. Allow 50.8 mm
(2 in.) of space on all sides for
adequate ventilation, as shown:
DIN Rail Mounting
The module can be mounted using the following DIN rails: 35 x 7.5 mm
(EN 50 022 - 35 x 7.5) or 35 x 15 mm (EN 50 022 - 35 x 15).
Before mounting the module on a DIN rail, close the DIN rail latch. Press the DIN rail
mounting area of the module against the DIN rail. The latch will momentarily open and lock
into place.
TIP
The 1762 expansion I/O may be mounted horizontally only.
ATTENTION
During panel or DIN rail mounting of all devices, be sure that all debris
(metal chips, wire strands, etc.) is kept from falling into the module.
Debris that falls into the module could cause damage when power is
applied to the module.
Side Side
Top
Bottom
MicroLogix 1200
1762 I/O 1762 I/O 1762 I/O

6MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
Use DIN rail end anchors (Allen-Bradley part number 1492-EA35 or 1492-EAH35) for
environments with vibration or shock concerns.
Panel Mounting
Use the dimensional template shown below to mount the module. The preferred mounting
method is to use two M4 or #8 panhead screws per module. M3.5 or #6 panhead screws may also
be used, but a washer may be needed to ensure a good ground contact. Mounting screws are
required on every module.
TIP
For environments with extreme vibration and shock concerns, use the
panel mounting method described below, instead of DIN rail
mounting.
End Anchor
End Anchor
90
(3.54)
100
(3.94)
40.4
(1.59)
40.4
(1.59)
14.5
(0.57)
For more than two modules: (number of modules - 1) x 40.4 mm (1.59 in.)
NOTE:
Hole spacing tolerance: ±0.4 mm (0.016 in.).
1762 I/O
1762 I/O
1762 I/O
MicroLogix 1200

MicroLogix 1200 RTD/Resistance Input Module 7
Publication 1762-IN014B-EN-P - July 2013
Field Wiring Connections
Grounding the Module
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. Refer to Industrial
Automation Wiring and Grounding Guidelines, Allen-Bradley publication 1770-4.1, for
additional information.
System Wiring Guidelines
Consider the following when wiring your system:
•Do not use the module’s NC terminals as connection points.
•Use Belden shielded, twisted-pair wire to ensure proper operation and high immunity to
electrical noise. See “RTD Wiring Considerations”.
•To limit noise, locate RTD and resistance device signal wires as far away as possible from
power lines, load lines, and other sources of electrical noise, such as hard-contact
switches, relays, and AC motor drives.
•Locate RTD modules away from other modules which generate a significant amount of
heat.
•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 1762-IR4 module end.
•Keep shield connection to ground as short as possible.
•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. See the table on the following page.
Terminal Block Layout
EXC 2
SENSE 2
RTN 2
EXC 3
SENSE 3
RTN 3
EXC 0
SENSE 0
RTN 0
EXC 1
SENSE 1
RTN 1
NC
NC
NC
NC
NC
NC
NC terminals are not intended for
use as connection points.
Do not connect any wires to the NC
terminals.

8MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
RTD Wiring Considerations
Since 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.
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 is eliminated.
To insure that the lead values match as closely as possible:
•Keep lead resistance as small as possible and less than 25Ω .
•Use quality cable that has a small tolerance impedance rating.
•Use a heavy-gauge lead wire which has less resistance per foot.
Configuration Recommended Cable
2-wire Belden™ 9501 or equivalent
3-wire — less than 30.48 m (100ft.) Belden™ 9533 or equivalent
3-wire — greater than 30.48 m (100 ft.) or high humidity conditions Belden™ 83503 or equivalent
IMPORTANT
The RTD module requires three wires to compensate for lead resistance
error. We recommend that you do not 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.
IMPORTANT
To ensure temperature or resistance value accuracy, the resistance
difference of the cable lead wires must be equal to or less than 0.01Ω .

MicroLogix 1200 RTD/Resistance Input Module 9
Publication 1762-IN014B-EN-P - July 2013
RTD Wiring Configurations
For a 3-wire configuration, the module can compensate for a maximum cable length associated
with an overall cable impedance of 25 ohms.
Three configurations of RTDs can be connected to the 1762-IR4 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 of a 4-wire RTD is left open.
2-Wire RTD Configuration
IMPORTANT
Using 2-wire configurations does not permit the module to compensate for
resistance error to do lead wire length. The resulting analog data includes
the effect of this uncompensated lead wire resistance. The module
continues to place the uncompensated analog data in the input data file, but
the open-circuit status bit (OCx) is set in word 4 of the input data file for
any enabled channel using a 2-wire configuration. These status bits may be
used in the control program to indicate that the analog data includes error
due to uncompensated lead wires. See page 16 for a detailed discussion of
the open-circuit status bits.
EXC 2
SENSE 2
RTN 2
NC
Belden 9501 Shielded Cable
Cable Shield (to Ground)
RTD EXC
Return
RTD EXC
Return

10 MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
3-Wire RTD Configuration
4-Wire RTD Configuration
Wiring Resistance Devices (Potentiometers)
Potentiometer wiring requires the same type of cable as that for the RTD described on page 8.
Potentiometers can be connected to the module as a 2-wire or 3-wire connection as shown on
page 11.
EXC 2
SENSE 2
RTN 2
NC
Belden 83503 or 9533 Shielded Cable
Cable Shield (to Ground)
RTD EXC
Sense
RTD EXC
Return
Sense
Return
EXC 2
SENSE 2
RTN 2
NC
Belden 83503 or 9533 Shielded Cable
Leave one sensor wire open.
Cable Shield (to Ground)
RTD EXC
Return
RTD EXC
Return
Sense Sense

MicroLogix 1200 RTD/Resistance Input Module 11
Publication 1762-IN014B-EN-P - July 2013
2-Wire Potentiometer Interconnection
IMPORTANT
Using 2-wire configurations does not permit the module to compensate for
resistance error to do lead wire length. The resulting analog data includes
the effect of this uncompensated lead wire resistance. The module
continues to place the uncompensated analog data in the input data file, but
the open-circuit status bit (OCx) is set in word 4 of the input data file for
any enabled channel using a 2-wire configuration. These status bits may be
used in the control program to indicate that the analog data includes error
due to uncompensated lead wires. See page 16 for a detailed discussion of
the open-circuit status bits.
EXC 2
SENSE 2
RTN 2
NC
EXC 2
SENSE 2
RTN 2
NC
Cable Shield (to Ground) Potentiometer
RTD EXC
Return
Cable Shield (to Ground)
Potentiometer
RTD EXC
Return
Belden 9501 Shielded Cable
Belden 9501 Shielded Cable
TIP
The potentiometer wiper arm can be connected to either the EXC or
return terminal, depending on whether you want increasing or decreasing
resistance.

12 MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
3-Wire Potentiometer Interconnection
EXC 2
SENSE 2
RTN 2
NC
EXC 2
SENSE 2
RTN 2
NC
Cable Shield (to Ground) Potentiometer
RTD EXC
Return
Sense
Run RTD EXC and sense wires from the module to potentiometer
terminal and tie terminal to one point.
Cable Shield (to Ground) Potentiometer
RTD EXC
Return
Sense
Run RTD EXC and sense wires from the module to potentiometer
terminal and tie terminal to one point.
TIP
The potentiometer wiper arm can be connected to either the EXC or
return terminal depending on whether you want increasing or decreasing
resistance.
Belden 83503 or 9533 Shielded Cable
Belden 83503 or 9533 Shielded Cable

MicroLogix 1200 RTD/Resistance Input Module 13
Publication 1762-IN014B-EN-P - July 2013
Labeling the Terminals
A write-on label is provided with the module. Mark the identification of each terminal with
permanent ink, and slide the label back into the door.
Wiring the Finger-Safe Terminal Block
When wiring the terminal block, keep the finger-safe cover in place.
1. Route the wire under the terminal pressure plate. You can use the stripped end of the
wire or a spade lug. The terminals will accept a 6.35 mm (0.25 in.) spade lug.
2. Tighten the terminal screw making sure the pressure plate secures the wire.
Recommended torque when tightening terminal screws is 0.904 Nm (8 lb-in.).
3. After wiring is complete, remove the debris shield.
ATTENTION
Be careful when stripping wires. Wire fragments that fall into a module
could cause damage when power is applied. Once wiring is complete,
ensure the module is free of all metal fragments.
TIP
If you need to remove the finger-safe cover, insert a screw driver into one
of the square wiring holes and gently pry the cover off. If you wire the
terminal block with the finger-safe cover removed, you will not be able
to put it back on the terminal block because the wires will be in the way.

14 MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
Wire Size and Terminal Screw Torque
Each terminal accepts up to two wires with the following restrictions:
Wiring Input Devices to the 1762-IR4
After the module is properly installed, follow the wiring procedure below, using Belden 83503 or
9533 shielded cable.
Wire Type Wire Size Terminal Screw Torque
Solid Cu-90 °C (194°F) #14…22 AWG 0.904 Nm (8 lb-in.)
Stranded Cu-90 °C (194°F) #16…22 AWG 0.904 Nm (8 lb-in.)
ATTENTION
Be careful when stripping wires. Wire fragments that fall into a module
could cause damage at power up. Once wiring is complete, ensure the
module is free of all metal fragments.
cable
signal wire (3)
drain wire
foil shield
signal wires (2)
Cut foil shield and
drain wire
signal wire
signal wire
drain wire foil shield
cable
signal wires (3)
Cut foil shield and
drain wire

MicroLogix 1200 RTD/Resistance Input Module 15
Publication 1762-IN014B-EN-P - July 2013
To wire your sensor to the 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 lengths. Strip about 3/16 inch (5 mm) of insulation away
to expose the end of the wire.
3. At one 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 at the preferred location based
on the type of sensor you are using.
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 module terminal block and input.
6. Repeat steps 1 through 5 for each channel on the module.
I/O Memory Mapping
A ddressing
The addressing scheme for 1762 Expansion I/O is shown below.
(1) I/O located on the controller (embedded I/O) is slot 0. I/O added to the controller (expansion I/O) begins with slot 1.
I1:x.0/0
File Type = Input
Data File
Slot Number (1)
Word
Bit
Bit Delimiter
Word Delimiter
Slot Delimiter

16 MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
Input Data File
For each module, slot x, words 0 through 3 contain the analog values of the inputs. Words 4 and
5 provide sensor/channel status feedback. The input data file for each configuration is shown
below.
The bits are defined as follows:
•Sx = General status bits for input channels 0…3. This bit is set (1) when an error (over-
or under-range, open-circuit or input data not valid condition) exists for that channel, or
there is a general module hardware error. An input data not valid condition is
determined by the user program. See the MicroLogix™ 1200 RTD/Resistance Input
Module User Manual, publication number 1762-UM003, for details.
•OCx = Open-circuit indication for channels 0…3, using either RTD or resistance inputs.
Short-circuit detection for RTD inputs only. Short-circuit detection for resistance
inputs is not indicated because 0 is a valid number.
•Ox = Over-range flag bits for input channels 0…3, using either RTD or resistance inputs.
These bits can be used in the control program for error detection.
•Ux = Under-range flag bits for channels 0…3, using RTD inputs only.
These bits can be used in the control program for error detection. Under-range detection
for direct resistance inputs is not indicated because 0 is a valid number.
Configuration Data File
The configuration of the format for analog inputs and outputs is made at going to run (GTR).
Changes made to the configuration file while in run mode have no effect. Words 0…3 of the
configuration file allow you to change the parameters of each channel independently. Word 0
corresponds to Channel 0, Word 1 to Channel 1, etc. The functional arrangement of the bits is
shown below for a single word/channel.
Word/
Bit 15 14 13 12 11 10 9876543210
0RTD/Resistance Input Data Channel 0
1RTD/Resistance Input Data Channel 1
2RTD/Resistance Input Data Channel 2
3RTD/Resistance Input Data Channel 3
4Reserved OC3 OC2 OC1 OC0 Reserved S3 S2 S1 S0
5U0 O0 U1 O1 U2 O2 U3 O3 Reserved

MicroLogix 1200 RTD/Resistance Input Module 17
Publication 1762-IN014B-EN-P - July 2013
To Select Make these bit settings
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Filter Frequency
10 Hz 1 1 0
60 Hz 0 0 0
50 Hz 0 0 1
250Hz 0 1 1
500 Hz 1 0 0
1 kHz 1 0 1
Excitation
Current
1.0 mA 0
0.5 mA 1
Cyclic Lead
Compensation
Enable 0
Disable 1
Open-circuit/
Broken Input
Upscale 0 0
Downscale 0 1
Last State 1 0
Zero 1 1
Temperature
Units Mode
°C 0
°F 1
Input/Sensor Type
100ΩPt 385 0 0 0 0
200ΩPt 385 0 0 0 1
500ΩPt 385 0 0 1 0
1000ΩPt 385 0 0 1 1
100ΩPt 3916 0 1 0 0
200ΩPt 3916 0 1 0 1
500ΩPt 3916 0 1 1 0
1000ΩPt 3916 0 1 1 1
10ΩCu 426 1 0 0 0
120ΩNi 618 1 0 0 1
120ΩNi 672 1 0 1 0
604ΩNiFe 518 1 0 1 1
150Ω1 1 0 0
500Ω1 1 0 1
1000Ω1 1 1 0
3000Ω1 1 1 1

18 MicroLogix 1200 RTD/Resistance Input Module
Publication 1762-IN014B-EN-P - July 2013
Module Configuration Word
Word 4 of the configuration data file contains the Enable/Disable Cyclic Calibration bit, as
shown in the table below.
Data Format
Raw/Proportional 000
Engineering Units 001
Engr. Units X 10 100
Scaled-for-PID 010
Percent Range 011
Enable
Channel
Enable 1
Disable 0
To Select Make these bit settings
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Cyclic
Calibration Enabled(1)
(1) When enabled, an autocalibration cycle is performed on all enabled channels every 5 minutes.
0
Disabled 1
To Select Make these bit settings
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

MicroLogix 1200 RTD/Resistance Input Module 19
Publication 1762-IN014B-EN-P - July 2013
Specifications
General Specifications
Specification Value
Dimensions, HxWxD 90 x 40 x 87 mm (3.54 x1.58 x 3.43 in.)
height including mounting tabs is 110 mm (4.33 in.)
Approximate Shipping Weight
(with carton) 260 g (0.57 lbs.)
Storage Temperature -40…85 °C (-40…185 °F)
Operating Temperature 0…55 °C (+32…131 °F)
Operating Humidity 5…95% non-condensing
Operating Altitude 2000 m (6561 ft)
Vibration Operating: 10…500 Hz, 5 g, 0.030 in. max. peak-to-peak
Shock Operating: 30 g
Bus Current Draw (max.) 40 mA @ 5V DC
50 mA @ 24V DC
Heat Dissipation 1.5 Watts
Input Group to System Isolation 30V AC/30V DC rated working voltage(1)
(N.E.C. Class 2 required)
(IEC Class 2 reinforced insulation)
type test: 500V AC or 707V DC for 1 minute
(1) Rated working voltage is the maximum continuous voltage that can be applied at the terminals with respect to earth ground.
Module Power LED On: indicates power is applied.
Vendor I.D. Code 1
Product Type Code 10
Product Code 65
Hazardous Environment Class Class I, Division 2, Hazardous Location, Groups A, B, C, D
ISA/ANSI 12.12.01
(C-UL under CSA C22.2 No. 213)
Radiated and Conducted Emissions EN50081-2 Class A
ESD Immunity (EN61000-4-2) 4 kV contact, 8 kV air, 4 kV indirect
Radiated Immunity (EN61000-4-3) 10 V/m, 80…1000 MHz, 80% amplitude modulation, +900 MHz
keyed carrier
Fast Transient Burst (EN61000-4-4) 2 kV, 5 kHz
Surge Immunity (EN61000-4-5) 1 kV galvanic gun
Conducted Immunity (EN61000-4-6) 10V, 0.15…80 MHz(2)
(2) Conducted Immunity frequency range may be 150 kHz to 30 MHz if the Radiated Immunity frequency range is 30 MHz to
1000 MHz.