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.ab.com/manuals/gi) 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
IMPORTANT
ATTENTION
WARNING
ATTENTION
Identifies information about practices or circumstances that can cause
an explosion in a hazardous environment, which may lead to personal
injury or death, property damage, or economic loss.
Identifies information that is critical for successful application and
understanding of the product.
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
• recognize the consequence
When 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 I/O is grounded through the DIN rail to chassis ground. Use
zinc plated yellow-chromate steel DIN rail to assure proper
grounding. The use of other DIN rail materials (e.g. aluminum,
plastic, etc.) that can corrode, oxidize, or are poor conductors, can
result in improper or intermittent grounding.
ATTENTION
ATTENTION
Environment and Enclosure
This equipment is intended for use in a Pollution Degree 2
industrial environment, in overvoltage Category II applications
(as defined in IEC publication 60664-1), at altitudes up to 2000
meters without derating.
This equipment is considered Group 1, Class A industrial
equipment according to IEC/CISPR Publication 11. Without
appropriate precautions, there may be potential difficulties
ensuring electromagnetic compatibility in other environments
due to conducted as well as radiated disturbance.
This equipment is supplied as "open type" equipment. It must
be mounted within an enclosure that is suitably designed for
those specific environmental conditions that will be present and
appropriately designed to prevent personal injury resulting from
accessibility to live parts. The interior of the enclosure must be
accessible only by the use of a tool. Subsequent sections of this
publication may contain additional information regarding
specific enclosure type ratings that are required to comply with
certain product safety certifications.
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.
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.
North American Hazardous Location Approval
The following modules are N ort h A m erican Hazardous Location approved:
1794-IM8 and 1794-OM8.
The following information applies when operating this
equipment in hazardous locations:
Products marked “CL I, DIV 2, GP A, B, C, D” are suitable for use
in Class I Division 2 Groups A, B, C, D, Hazardous Locations and
nonhazardous locations only. Each product is supplied with
markings on th e rating nameplate in dicating the hazardou s
location temp erature code. When com bining products within a
system, the most adverse temperature code (lowest “T”
number) may be used to help determine the overall temperat ure
code of the sys tem. Combinations of equipment in your syste m
are subject to in vestigation by the local Autho rity Having
Jurisdiction at the time of installation.
WARNING
EXPLOSION HAZARD
• D o not disconnect equ ipment
unless power has bee n removed or
the area is known to be
nonhazardous.
• Do not disconnect connections to
this equipment unless power has
been removed o r the area is known
to be nonhazardous. Secure any
external con nections that mate to
this equipment by using screws,
sliding latches, th readed
connectors, or other means
provided with this product.
• S ubstitution of components may
impair suitability f or Class I,
Division 2.
• If this product contains batteries,
they must only be changed in an
area known to be nonhazardous.
Informations sur l’utilisation de cet équipement en
environnements dangereux :
Les produits marqués "CL I, DIV 2, GP A, B, C, D" ne convien nent
qu’à une utilisation en environnements de Classe I Division 2
Groupes A, B, C, D dangereux et non dangereux. Chaque produit
est livré avec des marquages sur sa plaque d’identification qui
indiquent le cod e de température pour les environnements
dangereux. Lor sque plusieurs produits s ont combinés dans un
système, le code de t empérature le plus défavorable (cod e de
température le plu s faible) peut être utilis é pour déterminer le
code de température global du système. Les combinaisons
d’équipements dans le système son t sujettes à inspecti on par les
autorités locales qua lifiées au moment de l’insta llation.
AVERTISSEMENT
RISQUE D’EXPLOSION
• C ouper le courant ou s’ass urer que
l’environnement est classé non
dangereux avant de débrancher
l'équipement .
• C ouper le courant ou s'ass urer que
l’environnement est classé non
dangereux avant de débrancher les
connecteurs . Fixer tous les
connecteur s externes reliés à cet
équipement à l'aide de vis, loquets
coulissants, c onnecteurs filetés ou
autres moyens fournis avec ce produit.
• L a substitution de com posants peut
rendre cet éq uipement inadapté à u ne
utilisation en environnement de Classe
I, Division 2.
• S’assurer que l’environnement est
classé non da ngereux avant de
changer les piles.
Publication 1794-IN104A-EN-P - March 2004
2
Even Numbered I/O Terminals 0 thru 14
n)
L
L
U
Installing Your 220V ac Digital Input or Output Module
7
3
4
The module mounts on a 1794 terminal base.
ATTENTION
1. Rotate the keyswitch (1) on the terminal base (2) clockwise to position
8 as required for this type of module.
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.
WARNING
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.
During 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 on
power up.
If you remove or insert the module while the
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.
1
2
6
5
5. If daisychaining L1 power to the next terminal base, connect a jumper
from terminal 51 (220V ac L1) on this base unit to terminal 34 on the
next base unit.
6. If continuing 220V ac common (L2) to the next base unit, connect a
jumper from terminal 33 (220V common L2) on this base unit to
terminal 16 on the next base unit.
Wiring Connections for the 1794-IM8 and -OM8
1794-IM81794-OM8
1794-TBN
1
Input
Input
Ter m in al
Input 0B-0
Input 1B-2
Input 2B-4
Input 3B-6
Input 4B-8
Input 5B-10
Input 6B-12
Input 7B-14
B = Even numbered Input terminals 0-14,
ac common terminals 16 and 33
C = Power terminals C-34 and C-51, and
odd numbered input terminals 1 t hru 15
1 C-1, 3, 5, 7, 9, 11, 13 and 15 on the 1 794-TBN are internally connected in the module to
220V ac L1.
2 C-1, 3, 5, 7, 9, 11, 13 and 15 on the 1 794-TBN are internally connected in the module to
220V ac common L2.
220V ac
Supply
C-1
C-3
C-5
C-7
C-9
C-11
C-13
C-15
Output
1
Output 0 B-0
1
Output 1 B-2
1
Output 2 B-4
1
Output 3 B-6
1
Output 4 B-8
1
Output 5 B-10
1
Output 6 B-12
1
Output 7 B-14
B = Even numbered Output terminal s 0-14, ac
common terminals 16 and 33
C = Power terminals C-34 and C-51, a nd odd
numbered terminals 1-15 on row C.
1794-TBN, -TBNF
Output
Common
Te rm in al
C-1
C-3
C-5
C-7
C-9
C-11
C-13
C-15
2
2
2
2
2
2
2
2
1794-TBN or -TBNF Terminal Base Wiring for 1794-IM8 and
1794-OM8
L2
16
0
34
L1
1 = 220V ac power - Connect to terminal C-34
2 = 220V ac common - Connect to terminal B-16
se B-33 and C-51 for daisychaining to the next terminal base unit
4
2
1
6789101112
3
5
Odd Numbered I/O Terminals 1 thru 15
L2
14
33
13
15
B
51
C
L1
(1794-TBN show
Connecting Wiring for the 1794-IM8 and -OM8
1. Connect individual input or output wiring to numbered terminals on
row (B) as indicated in the table below.
2. 1794-IM8: Connect the associated 220V ac L1 power lead of the input
device to the corresponding odd numbered terminal (C-1, 3, 5, 7, 9,
11, 13, or 15) on row (C) for each input as indicated in the table below.
Configuring Your ac Module
Image Table Memory Map for the 1794-IM8
Dec.15 14 13 12 11 10 9876543210
Oct.17 16 15 14 13 12 11 10 76543210
ReadNot used - set to 0I7 I6 I5 I4 I3 I2 I1 I0
WriteNot used - s et to 0Filter Time FT
Where I = Input stat us
FT = Input filter time.
(The 220V L1 power terminals of row (C) are internally connected
together.)
1794-OM8: Connect the associated 220V ac common L2 lead of the
output device to the corresponding odd numbered terminal (C-1, 3, 5,
7, 9, 11, 13, or 15) on row (C) as indicated in the table below. (The
220V L2 commons of odd numbered terminals on row (C) are
internally connected together.)
Image Table Memory Map for the 1794-OM8
Dec.15 14 13 12 11 10 9876543210
Oct.17 16 15 14 13 12 11 10 76543210
Read Not used - set to 0
WriteNot used - s et to 0O7O6O5O4O3O2O1O
Where O = Output status
0
3. Connect 220V ac power (L1) to terminal 34 on the row (C).
4. Connect 220V ac common (L2) to terminal 16 on the
row (B).
Publication 1794-IN104A-EN-P - March 2004
Setting the 1794-IM8 Input Filter Time
To select your input filter time (FT) for channels 00-07, set the corresponding
bits in the output image table (complementary word) for the module.
15 14 13 12 11 10 9 87 6 5 4 3 2 10
O:010
FT = 0-07
Dec.
Input Filter Time for the 1794-IM8
BitsDescription
02 01 00 Filter Time - inputs 00-07Off to On On to Off
000Filter Time 0 (Default)256µs7.526.5
001Filter Time 1512µs827
010Filter Time 21ms928
011Filter Time 32ms1029
100Filter Time 44ms1231
101Filter Time 58ms1635
110Filter Time 616ms24.544
111Filter Time 732ms4260.5
Selected
Filter
Time
Maximum Filter
Time (ms)
For example, setting bits 00, 01 and 02 as shown below sets the off-to-on filter
time for inputs 00 thru 07 to 12ms. For other settings, refer to the Input Filter
Time table above.
Write filter time on system startup.
I:000
00
1794-IM8
FLL
Fill File
Source
Destination
Length
7654321 0
#O:010
1
1
0
0
Write FT to complement
of input module.
= 4 Octal or 4 Decimal
Specifications
Specifications220V ac Input Module, Cat. No. 1794-IM8
Number of Inputs8, (1 group of 8), nonisolated
Module LocationCat. No. 1794-TBN
Module MountingSee Derating Curve
On-state Voltage159V ac minimum
On-state Current5.27mA minimum @ 159V ac, 47Hz
Off-state Voltage40V ac maximum
Off-state Current2.6mA maximum
Input Impedance22.3K ohm s nominal
Nominal Input Current10mA @ 220V ac, 60Hz
Isolation VoltageTested at 2600V dc for 1s between user and system
Input Filter Time
Flexbus Current30 mA @5V dc
Power Dissipation4.7W m aximum @ 264V ac
Thermal DissipationMaximum 16.2 BTU/hr @ 2 64V ac
220V ac nominal
264V ac maximum
9.88mA nominal @ 220V ac, 60Hz
13.21mA maximum @ 264V ac, 63Hz
No isolation between individual chan nels
No isolation between customer p ower and input channels
1
Refer to Input Filter Time table
3
Specifications220V ac Output Module Cat. No. 1794-O M8
Number of Outputs8, (1 group of 8), nonisolated
Module LocationCat . No. 1794-TBN, -TBNF
Module MountingSee Derating Curve
Output Current Rating4.0A (8 o utputs @ 500mA)
On-state Current50mA p er output minimum
On-state Voltage Dropmaximum 1.5V ac @ 0.5A
Surge Current7A for 40ms, repeatable every 8s
Off-state leakage2.5mA maximum
Isolation VoltageTested at 2600V dc for 1s between us er and system
Output Signal Delay Time
Off to On
On to Off
Flexbus Current60mA @5V dc
Power Dissipation5.0W maximum @ 0.5A
Thermal DissipationMaximum 17.1 BTU/hr @ 0.5A
Fusing (when using the
3
1794-TBNF)
General Specifications
Terminal Base Screw
Torque
Dimensions (with module
installed)
Indicators (field side
indication, custome r
device driven)
External ac power
Supply voltage
Input Frequency
Voltage range
10V/m with 1kHz sine-wave 80%AM f rom 30MHz to 1000MHz
10V/m with 200Hz 50% Pulse 100%A M at 900Mhz
±2kV at 5kHz on signal ports
±2kV at 5kHz on power ports
IEC 61000-4-5:
±1kV line-line(DM) and ±2kV line-earth(CM ) on signal ports
±1kV line-line(DM) and ±2kV line-earth(CM) on power ports
IEC 61000-4-6:
10Vrms with 1kHz sine-wave 80%AM from 150kHz to 80MHz
Publication 1794-IN104A-EN-P - March 2004
Conductors Wire Size
Category
Certifications (when
product is marked)
1 Input off-to-on filt er time is the time from a val id input signal to recognit ion by the module. Input on- to-off filter
time is time from the input signal dropping be low the valid level to recogn ition by the module.
2 Delay time is the time from the mrec eipt of an output on or off command to the out put actually turning on or off.
3 Module output s are not fused. We recom mend that outputs be f used. If not using the 1 794-TBNF, and fusing is
desired, it mus t be provided externall y.
4 You use this category information for plannin g conductor routing as described in Allen- Bradley
publication 1770 -4.1, Industrial Automa tion Wiring and Grounding Guidelines.
5 For the latest up-to-date information, see the Product Certification link at www.ab.com for Declarations of
Conformity, Certific ates and other certifi cation details. For no tification of any add itional release notes, r efer to
www.ab.com/manuals/ .
12 to 22AWG (4 to 0.25mm2) stranded copper wire rated at 60°C o r
higher
3/64 inch (1.2mm) insulation maximum
4
2
UL UL Listed In dustrial Control Equipment
5
CSA CSA certified for Class I, Division 2, Groups A, B, C and D
Hazardous locations
CE5European Union 89/336/EEC EMC D irective,
compliant with:
EN 61000-6-4; Industrial Emis sions
EN 50082-2; Industrial Immu nity
EN 61326; Meas./Control/Lab., Indus trial Requirements
EN 61000-6-2; Industrial Immu nity
European Union 73/23/EEC LVD Directive, com pliant with:
EN 61131-2; Programmable Contro llers
C-Tick5 - Australian Radiocommunication s Act compliant with
AS/NZS CISPR 11, Industrial Emission s
1794-IM8 Derating Curve
264
250
235
Vin
On–state
220
Voltage
(V ac)
205
190
175
150
0
1020304050 55 60
The area within the curve represents the safe operating range for the module under various
conditions of user supplied 220V ac supply voltages and ambient temperatures.
= All mounting positions (including normal horizontal, vertical,
inverted horizontal) safe operating range
Voltage (maximum)Temperature (maximum)
26446
25055
Ambient Temperature
46
o
C
1794-OM8 Derating Curve
264
250
235
Vin
O n–state
220
Voltage
(V ac)
205
190
175
150
0
1020304050 55 60
The area within the curve represents the safe operating range for the module
under various conditions of user supplied 220V ac supply voltages and ambient
temperatures.
= Normal mounting safe operating range. Includes
= Other mounting positions (including inverted horizontal, vertical)
safe operating range
normal horizontal55
Other mounting positions
(including inverted horizontal, vertical)
Ambient Temperature
MountingT emperature (maximum)
49
o
C
49
Publication 1794-IN104A-EN-P - March 2004 4PN 957824-75