Allen-Bradley FLEX Ex 1797-IRT8 User manual

Publication 1797-IN004G-EN-P - August 2017
Installation Instructions
FLEX Ex Thermocouple/RTD Input Module
Catalog Number 1797-IRT8
Contents
For Information About See Page
Important User Information 2
Module Installation 3
Installation in Zone 1 5
Installation in Zone 22 5
European Communities (EC) Directive Compliance 6
Inputs 8
Indicators 14
Output Map 15
Fault Mode - Write Word 0 16
Add-on Filter Selections - Write Word 0 16
Reference Junction Selection - Write Word 0 16
RTD Offset Select - Write Word 2 17
Sensor Type Select - Write Word 1 18
Specifications 19
Entity Parameters 23

2FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Important User Information
Solid state equipment has operational characteristics differing from those of electromechanical
equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls
(Publication SGI-1.1 available from your local Rockwell Automation sales office or online at
http://www.literature.rockwellautomation.com) describes some important differences between solid
state equipment and hard-wired electromechanical devices. Because of this difference, and also because
of the wide variety of uses for solid state equipment, all persons responsible for applying this equipment
must satisfy themselves that each intended application of this equipment is acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages
resulting from the use or application of this equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of the
many variables and requirements associated with any particular installation, Rockwell Automation, Inc.
cannot assume responsibility or liability for actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits,
equipment, or software described in this manual.
Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell
Automation, Inc., is prohibited.
Throughout this manual we use notes to make you aware of safety considerations.
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.
IMPORTANT
Identifies information that is critical for successful application and understanding of the
product.
ATTENTION
Identifies information about practices or circumstances that can lead to personal injury or
death, property damage, or economic loss. Attentions help you identify a hazard, avoid a
hazard, and recognize the consequence
SHOCK HAZARD
Labels may be located on or inside the product to alert people that dangerous voltage
may be present.
BURN HAZARD
Labels may be located on or inside the product to alert people that surfaces may be
dangerous temperatures.

FLEX Ex Thermocouple/RTD Input Module 3
Publication 1797-IN004G-EN-P - August 2017
Module Installation
This module must be used with a 1797-TB3 or 1797-TB3S intrinsically safe
terminal base unit.
Component Identification
1 Keyswitch 5 Alignment Bar
2 Terminal Base Unit 6 Alignment Groove
3 Flexbus Connector 7 Latching Mechanism
4 Module 8 Cap Plug
1
2
3
45
6
7
Label Here or
Under Here
8
40231

4FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
1. Rotate keyswitch (1) on terminal base unit (2) clockwise to position 2 as
required for this type of module.
Do not change the position of the keyswitch after wiring the
terminal base unit.
2. Make certain the flexbus connector (3) is pushed all the way to the left to
connect with the neighboring terminal base/adapter.
You cannot install the module unless the connector is fully extended.
3. Make sure the pins on the bottom of the module are straight so they will
align properly with the connector in the terminal base unit.
4. Position the module (4) with its alignment bar (5) aligned with the groove
(6) on the terminal base.
5. Press firmly and evenly to seat the module in the terminal base unit.
The module is seated when the latching mechanism (7) is locked into
the module.
6. Make certain that you only connect terminal base units to other intrinsi-
cally safe system modules or adapters to maintain the integrity of the
intrinsically-safe backplane.
ATTENTION
This equipment is considered Group 1, Class A industrial
equipment according to IEC/CISPR Publication 11. Without
appropriate precautions, there may be potential difficulties
ensuring electromagnetic compatibility in other environments
due to conducted as well as radiated disturbance.
This equipment is supplied as open-type equipment. It must be
mounted within an enclosure that is suitably designed for those
specific environmental conditions that will be present and
appropriately designed to prevent personal injury resulting from
accessibility to live parts. The interior of the enclosure must be
accessible only by the use of a tool. Subsequent sections of this
publication may contain additional information regarding
specific enclosure type ratings that are required to comply with
certain product safety certifications.
20128M

FLEX Ex Thermocouple/RTD Input Module 5
Publication 1797-IN004G-EN-P - August 2017
7. Remove cap plug (8) and attach another intrinsically safe terminal base
unit to the right of this terminal base unit if required.
Installation in Zone 1
This module must not be exposed to the environment. Provide a suitable
metal enclosure. This module has a protection factor of IP20.
Installation in Zone 22
When the module is installed in Zone 22, the following cabinets must be used:
IVK-ISRPI-V16LC; IVK-ISRPI-V8HYW; or IVK-ISRPI-V8LC. These
cabinets can be purchased from Pepperl+Fuchs GmbH, Lilienthalstrasse 200
68307 Mannheim, Germany. Information available at
www.pepperl-fuchs.com.
The IS-RPI cabinets (type IVK2-ISRPI-V8LC, IVK2-ISRPI-V8HYW, or
IVK2-ISPRI-V16LC) ensures the basic protection for the intrinsically safe
apparatus of the FLEX Ex I/O system for use in Zone 22. It corresponds
with category 3D according to RL 94/9 EG and with the type label marked
with the following information:
Pepperl+Fuchs GmbH
68307 Mannheim
IVK2-ISRPI-V8LC (or IVK2-ISRPI-V8HYW or IVK2-ISRPI-V16LC)
EX II 3 D Ex tD A22 IP54 T70 °C
CE
Serial (manufacturing) number
Model
Electrostatic Charge
Protect the system against electrostatic charge. Post a sign near this module:
WARNING Avoid electrostatic charging.
ADVERTÊNCIA! PREVENIR CONTRA O ACÚMULO DE CARGA
ELETROSTÁTICA.
For your convenience, a sign that can be cut out and posted is included in this
installation instruction.
ATTENTION
This module cannot be used in an intrinsically safe
environment after it has been exposed to nonintrinsically
safe signals.

6FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Removal and Insertion Under Power
European Communities (EC) Directive Compliance
If this product has the CE mark it is approved for installation within the
European Union and EEA regions. It has been designed and tested to meet
the following directives.
EMC Directive
These products are tested to meet the Council Directive 2014/30/EU by
applying the following standards:
•EN 61000-6-4:2007, Electromagnetic Compatibility (EMC) - Part 6-4:
Generic Standard for Industrial Environments (Class A)
•EN 61000-6-2:2005, Electromagnetic Compatibility (EMC) - Part 6-2:
Generic Standards - Immunity for Industrial Environments
•EN 61326-1:2013 (Industrial), Electrical Equipment For
Measurement, Control, and Laboratory Use - Industrial EMC
Requirements
WARNING
These modules are designed so you can remove and insert
them under power. However, take special care when removing
or inserting modules in an active process. I/O attached to any
module being removed or inserted can change states due to its
input or output signal changing conditions.
If you insert or remove the module while backplane 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.

FLEX Ex Thermocouple/RTD Input Module 7
Publication 1797-IN004G-EN-P - August 2017
European Hazardous Location Approval
The following applies to products marked II (1)2 G and
II (1) D
•Are Equipment Group II, Equipment Category (1) 2, and comply
with the Essential Health and Safety Requirements relating to the
design and construction of such equipment given in Annex II to
Directive 2014/34/EU. See the EC Declaration of Conformity at
http://www.rockwellautomation.com/products/certification
for details.
•The type of protection is “Ex ib[ia] IIC T4” and “[Ex iaD]” according
to EN 60079-11.
•Comply to Standards EN 60079-0:2006, EN60079-11:2007,
EN 60079-26:2004, EN 61241-0:2006, and EN 61241-11:2006,
reference certificate number DMT 98 ATEX E 023 X.
•Are intended for use in areas in which explosive atmospheres caused
by gases, vapors, mists, or air are likely to occur occasionally. Such
locations correspond to Zone 1 or 2 classification according to ATEX
directive 2014/34/EU.
IEC Hazardous Location Approval
The following applies to products with the IECEx certification:
•Are intended for use in areas in which explosive atmospheres caused
by gases, vapors, mists, or air are likely to occur only infrequently and
for short periods. Such locations correspond to Zone 1 or 2
classification to IEC 60079-0.
•The type of protection is “[Zone 0] Ex ib[ia] IIC T4” according to
IEC 60079-11 and “[Ex iaD]” according to IEC 60079-11.
•Comply to Standards IEC 60079-0:2004, IEC 60079-11:2006,
IEC 60079-26:2004, IEC 61241-0:2004, and IEC 61241-11:2005,
reference IECEx certificate number IECEx BVS 09.0029X.

8FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Special Conditions for Safe Use:
The module may only be used with the terminal base type 1797-TB3/* or
type 1797-TB3S/* (DMT 98 ATEX E012U)
A warning label shall be installed in immediate proximity of these apparatus:
ATTENTION! Avoid electrostatic charging.
Inputs
Each input can be operated from a thermocouple (TC) or resistance
temperature detector (RTD). Do not apply any nonintrinsically safe
signals to this module.
When using an intrinsically safe electrical apparatus according to EN50020,
the European directives and regulations must be followed.
The channels in this module are electrically connected to each other and have
a common plus-line.
IMPORTANT
When interconnecting several lines, you must consider the
total accumulated power and check for intrinsic safety.
Thermocouple
Flexbus Bus
uC
+V Power
Supply
-V
L
H
-
+
+
mV
-
2W RTD 3W RTD 4W RTD
CJC
+
-
GND
irt8custconxn

FLEX Ex Thermocouple/RTD Input Module 9
Publication 1797-IN004G-EN-P - August 2017
Wire to a 1797-TB3 or 1797-TB3S Terminal Base Unit
Connect wiring to the terminal base as shown below.
Wiring
1. For RTD inputs:
a. connect the individual source current input wiring to (+) terminals for
each individual channel (0, 4, 8, and 12) on the 0 to 15 row (A) and
terminals 17, 21, 25, and 29 on the 16 to 33 row (B) as indicated in the
table below.
b. connect the associated signal return (-) to the corresponding (-)
terminals (3, 7, 11, and 15) on the 0 to 15 row (A), and terminals 20, 24,
28, and 32 on the 16 to 33 row (B).
2. For thermocouple inputs:
a. connect the individual high signal input wiring to (L) terminals for
each individual channel (2, 6, 10, and 14) on the 0 to 15 row (A) and
terminals 19, 23, 27, and 31 on the 16 to 33 row (B) as indicated in the
table below.
b. connect the associated low signal (-) to the corresponding (-)
terminals (3, 7, 11, and 15) on the 0 to 15 row (A), and terminals 20, 24,
28, and 32 on the 16 to 33 row (B).
c. connect cold junction compensation wiring to terminals 37, 38, and
39, and terminals 46, 47, and 48.
+-
Ch 0 Ch 1 Ch 2 Ch 3
+V -V +V -V
01 234567891011121314 15
16 17 1819 20 21 22 2324 25 26 27 2829 30313233
3435363738 394041424344 45 46 47 4849 50 51
LH +- LH +- LH +-
LH
+-
Ch 4 Ch 5 Ch 6 Ch 7
LH +-
LH +- LH +- LH
CJC
0+ 0- CJC
1+ 1-
Chassis
GND
for shield
Row A
Row B
Row C
Chassis
GND
for shield
No connection allowed to terminals36, and 49
41505

10 FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
d. Connect the tail of the CJC as follows:
• when using inputs 0 to 3 (row A) only for thermocouple inputs:
connect the tail of CJC1 to terminal 5 and CJC2 to terminal 12 on row
A.
• when using inputs 4 to 7 (row B) only for thermocouple inputs:
connect the tail of CJC1 to terminal 22 and CJC2 to terminal 29 on
row B.
• when using thermocouple inputs 0 to 7: connect the tail of CJC1 to
terminal 5 on row A, and CJC2 to terminal 29 on row B.
3. Connect +V to terminal 34 on the 34 to 51 row (C).
4. Connect -V to terminal 35 on the 34 to 51 row (C).
5. If continuing power to the next terminal base unit, connect a jumper from
terminal 50 (+V) on this base unit to terminal 34 on the next base unit.
6. If continuing common to the next terminal base unit, connect a jumper
from terminal 51 (-V) on this base unit to terminal 35 on the next base
unit.
IMPORTANT
Whenever you use thermocouple inputs, you must use both
cold junction compensators
WARNING
Make certain that you power this module with an intrinsically
safe power supply. Do not exceed the values listed in the
specifications for this module.
If you connect or disconnect wiring while the field-side 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.

FLEX Ex Thermocouple/RTD Input Module 11
Publication 1797-IN004G-EN-P - August 2017
Type of Input Connect the Following
+ H L - Shield1
RTD - 2-wire 1 2
RTD - 3-wire 1 3 2
RTD - 4-wire 11a 2a 2
Thermocouple 1 2
Millivolt 1 2
1Terminals 16, 33, 40…45 are chassis ground.
RTD or
Thermocouple
Channel
RTD Source
Current
(+)
High Signal
Terminal
(H)
Low Signal
Terminal
(L)
Signal
Return
(-)
0 0 1 2 3
1 4 5 6 7
2 8 9 10 11
312 13 14 15
417 18 19 20
521 22 23 24
625 26 27 28
729 30 31 32
+V Terminals 34 and 50
-V Terminals 35 and 51
1 Terminals 37, 38, and 39, and 46, 47, and 48 are for cold junction
compensation (with 38, and 47 chassis ground). Connect CJC1 to
terminal 5 or 22, CJC2 to terminal 12 or 29
2 Terminals 16, 33, and 40…45, are chassis ground.
ATTENTION
Do not use the unused terminals on this terminal base unit.
Using these terminals as supporting terminals can result in
damage to the module and/or unintended operation of your
system.
1
2
3
1a
2a
1
2
1
2
1
2
1
2
2-wire RTD
3-wire RTD
4-wire RTD
Thermocouple
Millivolt

12 FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Example of 2-, 3-, and 4-wire RTD and Thermocouple Wiring to a 1797-TB3
Terminal Base Unit
16
34
120 3 4 5 6 7 8 9 10 11 12 13 14 15
A
B
C
Thermocouple Channel 4
2-Wire RTD Channel 1
3-Wire RTD Channel 2
4-Wire RTD Channel 3
1797-TB3
CJC = cold-junction compensation thermistor
Attention: Keep exposed area of inner conductor as short as possible.
0 to 15
16 to 33
34 to 51
CJC
CJC
Bus Bar Ground
or Shield
Terminating
Feedthrough
40621gm

FLEX Ex Thermocouple/RTD Input Module 13
Publication 1797-IN004G-EN-P - August 2017
Example of Millivolt Wiring to a 1797-TB3 Terminal Base Unit
Grounding
All I/O wiring must use shielded wire. Shields must be terminated external to
the module, such as bus bars and shield-terminating feed throughs.
0 to 15
16 to 33
34 to 51
A
B
C
Millivolt
Source Millivolt
Source Millivolt
Source Millivolt
Source
+-
+-
+-
-
+
-
-
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16
34
Attention: Keep exposed area of inner conductor as short as possible. 40622gm
Bus Bar Ground
or Shield
Terminating
Feedthrough
30820-M

14 FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Indicators
A= Status Indicators -
Flashing red - channel fault - Channel 0 indicator will
turn red while power-up check is running.
(Channel 0 solid red - module did not pass power-up test.)
B= Insertable labels for writing individual I/O designations
C= Power Indicator - green - indicates power applied to module
Input Map
Bit15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
WordRead
0Channel 0 Input Data
1Channel 1 Input Data
2Channel 2 Input Data
3Channel 3 Input Data
4Channel 4 Input Data
5Channel 5 Input Data
6Channel 6 Input Data
7Channel 7 Input Data
8Overrange Alarm Bits (channel 0 = bit 08, ch 1 = bit 09,
and so on)
Underrange Alarm Bits (ch 0 = bit 00, ch 1 = bit01,
and so on)
9Flt
Alm
ch
7
Flt
Alm
ch
6
Flt
Alm
ch
5
Flt
Alm
ch
4
Flt
Alm
ch
3
Flt
Alm
ch
2
Flt
Alm
ch
1
Flt
Alm
ch
0
CJC
2
Alm
CJC
1
Alm
Diagnostic Status
10 Module command response Module response data
Ex
1797-IRT8
PWR
ABC

FLEX Ex Thermocouple/RTD Input Module 15
Publication 1797-IN004G-EN-P - August 2017
Output Map
Data Format for All Channels - Write Word 0
Bit15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
WordWrite
0Data Format Flt
Mode
ch
4…7
Flt
Mode
ch
0…3
Reference
Junction
Filter Cutoff
1TC/RTD
Ch 4…7
Sensor
Mode
ch 4…7
Sensor Type
Ch 4…7
TC/RTD
Ch 0…3
Sensor
Mode
Ch 0…3
Sensor Type
Ch 0…3
2RTD
Offset
ch 7
RTD
Offset
ch 6
RTD
Offset
ch 5
RTD
Offset
ch 4
RTD Offset
ch 3
RTD Offset
ch 2
RTD
Offset
ch 1
RTD
Offset
ch 0
3Module command Module command data
Bit 11 10 09 08 Data type for channels 0…7
0 0 0 0 °C (see note)
0 0 0 1 °F (see note)
0 0 1 0 °K (see note)
0 0 1 1 -32767…+32767
0 1 0 0 0…65535
0101 to 1111 not used
Note: Module defaults to -4000…10,000 in Millivolt mode, and 0…5000 in Ohms mode.

16 FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Fault Mode - Write Word 0
Add-on Filter Selections - Write Word 0
Reference Junction Selection - Write Word 0
Bit 06 Fault enable for channels 0…3
07 Fault enable for channels 4…7
0 = disabled
1 = enable wire-off detection
Bit 02 01 00 Definition
0 0 0 Hardware filtering only (default filtering)
0 0 1 40 Hz (25 ms)
0 1 0 10 Hz (100 ms)
0 1 1 4 Hz (250 ms)
1 0 0 2 Hz (500 ms)
1 0 1 1 Hz (1 s)
1 1 0 0.5 Hz (2 s)
1 1 1 0.2 Hz (5 s)
Bits
03…05
Reference Junction - used when sensor is set to thermocouple
and sensor mode is set to internal compensation. Sets a fixed
reference junction to compensate all thermocouple channels.
Bit 05 04 03 Reference Junction
0000 °C
00120 °C
01025 °C
01130 °C
10040 °C
10150 °C
11060 °C
11170 °C

FLEX Ex Thermocouple/RTD Input Module 17
Publication 1797-IN004G-EN-P - August 2017
Sensor Mode Select - Write Word 1
RTD Offset Select - Write Word 2
Bit 05 04 Sensor mode for channels 0…3
13 12 Sensor mode for channels 4…7
Thermocouple Mode
0 0 External compensation - uses cold junction sensor
0 1 Internal compensation - Uses the value selected for
reference junction
1 0 No compensation (Data is referenced to 0 °C)
1 1 Differential measurement between 2 channels
RTD Mode
0 0 2-wire RTD - no compensation
0 1 2-wire RTD with user compensation
1 0 3-wire RTD
1 1 4-wire RTD
Bit 01 00 RTD Offset Select Bits - Channel 0
03 02 RTD Offset Select Bits - Channel 1
05 04 RTD Offset Select Bits - Channel 2
07 06 RTD Offset Select Bits - Channel 3
09 08 RTD Offset Select Bits - Channel 4
11 10 RTD Offset Select Bits - Channel 5
13 12 RTD Offset Select Bits - Channel 6
15 14 RTD Offset Select Bits - Channel 7
0 0 Use channel loop compensation value stored during
calibration procedure for 2-wire RTD (default = 0 Ω)
0 1 5 Ω
1 0 10 Ω
1 1 15 Ω
Note: This parameter not applicable for Cu 10 Ω, which defaults to 0 Ω.

18 FLEX Ex Thermocouple/RTD Input Module
Publication 1797-IN004G-EN-P - August 2017
Sensor Type Select - Write Word 1
RTD Type
Bit 03 02 01 00 Sensor type for channels 0…3
Bit 11 10 09 08 Sensor type for channels 4…7
0 0 0 0 Resistance (default)
0 0 0 1 100 ΩPt α= 0.00385 Euro (-200…+870 °C)
0 0 1 0 200 ΩPt α_ = 0.00385 Euro (-200…+380 °C)
0 0 1 1 100 ΩPt α= 0.003916 U.S. (-200…+630 °C)
0 1 0 0 200 ΩPt α= 0.003916 U.S. (-200…+377 °C)
0 1 0 1 100 ΩNickel α = 0.00618 U.S. (-60…+250 °C)
0 1 1 0 200 Ω Nickel α = 0.00618 U.S. (-60…+200 °C)
0 1 1 1 120 ΩNickel α = 0.00672 U.S. (-80…+320 °C)
1 0 0 0 10 ΩCopper α = 0.00427 U.S. (-200…+260 °C)
1001…1111 not used
Thermocouple Type
Bit 03 02 01 00 Sensor type for channels 0…3
Bit 11 10 09 08 Sensor type for channels 4…7
0 0 0 0 mV (default)
0 0 0 1 B 300…1800 °C (572…3272 °F)
0 0 1 0 E -270…1000 °C (-454…1832 °F)
0 0 1 1 J -210…1200 °C (-346…2192 °F)
0 1 0 0 K -270…1372 °C (-454…2502 °F)
0 1 0 1 TXK/XK(L) -200…800 °C (-328…1472 °F)
0 1 1 0 N -270…1300 °C (-454…2372 °F)
0 1 1 1 R -50…1768 °C (-58…3214 °F)
1 0 0 0 S -50…1768 °C (-58…3214 °F)
1 0 0 1 T -270…400 °C (-454…752 °F)
1010…1111 not used

FLEX Ex Thermocouple/RTD Input Module 19
Publication 1797-IN004G-EN-P - August 2017
Repair
This module is not field-repairable. Any attempt to open this module will void
the warranty and IS certification. If repair is necessary, return this module to
the factory.
Specifications
Specifications - 1797-IRT8 Thermocouple/RTD Module
Number of Inputs 8 channels
IS input type Ex ia IIB/IIC T4
AEx ia IIC T4
Class I, II, III, Division 1 Group A-G T4
IS module type Ex ib IIB/IIC T4
AEx ib IIC T4
Class I, Division 1 Group A-G T4
Input Type Suitable for Pt 100, Pt 200, Ni 100, Ni 120, Ni 200, 10 Cu RTD,
thermocouple Type B, E, J, K, N, R, S, T, TXK/XK (L)
Configuration via internal bus
Signal Input Range 0…485 Ω; -40…100 mV
Settling Time to 99% of Final
Value
8 ms (mV mode, °F thermocouple)
Open RTD Detection Out of range upscale reading
Lead Resistance
Compensation
< 15 W total
Transfer Characteristics
Accuracy
Temperature Effect
RTDs: 0.1% of span @ 20 °C, filter cutoff < 1 Hz
Thermocouples: 0.1% of span @ 20 °C,
filter cutoff < 1 Hz
Cold junction compensation = +1 oC
150 ppm/oC (primary range)
Indicators 8 red fault indicators
1 green module power indicator
Specifications continued on next page