Allen-Bradley FLEX I/O 1794-OB8EP User manual


  #  $""   & %$ $  %$  '  !" 
   
 

(Cat. No. 1794-OB8EP)







 
This module mounts on a 1794 terminal base unit.
1. Rotate keyswitch (1) on terminal base unit (2) clockwise to position 2
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 that 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.
Installation Instructions
AB Drives

24V dc FLEX I/O Electronically Fused 8 Output Module2
   
!ATTENTION: Remove field-side power before
removing or inserting this module. This module is
designed so you can remove and insert it under
backplane power. When you remove or insert a module
with field-side 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
Repeated electrical arcing causes excessive wear to
contacts on both the module and its mating connector.
Worn contacts may create electrical resistance.
   
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
This product is tested to meet Council Directive 89/336/EEC
Electromagnetic Compatibility (EMC) and the following standards, in
whole or in part, documented in a technical construction file:
•EN 50081-2 EMC – Generic Emission Standard, Part 2 – Industrial
Environment
•EN 50082-2 EMC – Generic Immunity Standard, Part 2 – Industrial
Environment
This product is intended for use in an industrial environment.
Low Voltage Directive
This product is tested to meet Council Directive 73/23/EEC Low Voltage,
by applying the safety requirements of EN 61131–2 Programmable
Controllers, Part 2 – Equipment Requirements and Tests.
For specific information required by EN 61131-2, see the appropriate
sections in this publication, as well as the following Allen-Bradley
publications:
•Industrial Automation Wiring and Grounding Guidelines For Noise
Immunity, publication 1770-4.1
•Automation Systems Catalog, publication B111
This equipment is classified as open equipment and must be mounted in
an enclosure during operation to provide safety protection.

24V dc FLEX I/O Electronically Fused 8 Output Module 3
"! $   
Wiring to a 1794ĆTB3 or ĆTB3S Terminal Base Unit
1. Connect individual output wiring (customer loads) to even-numbered
terminals 0 through 14 on the 0 to 15 row (A).
2. Connect the associated return to the corresponding terminal on the
16–33 row (B) or to the odd-numbered terminals on the 0–15 row (A)
as indicated in the wiring table below. (Returns are internally
connected together.)
3. Connect +24V dc power to terminal 34 on the 34–51 row (C).
4. If continuing power to the next terminal base unit, connect a jumper
from terminal 51 (+24V dc) on this base unit to terminal 34 on the
next base unit.
5. Connect 24V dc return to terminal 16 on the 16–33 row (B).
6. If continuing 24V return to the next terminal base unit, connect a
jumper from terminal 33 (return) on this base unit to terminal 16 on
the next base unit.
                
               

 
                

1794ĆTB3
0 -15
34-51
16-33
A
B
C
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
18 19 20 21 22 23 3324 25 26 27 28 29 30 31 3217
35 36 37 38 47 48 49 5034 51
16
  ! !  #   
# 
# 
# 
# 
# 
# 
39 40 41 42 43 44 45 46
1794ĆTB3S
AB Drives

24V dc FLEX I/O Electronically Fused 8 Output Module4
Publication 1794Ć5.20- April 1999
Output Channel
1794ĆTB3, ĆTB3S
Output Channel
Output Terminal Common Terminal1
0 AĆ0 AĆ11/BĆ17
1 AĆ2 AĆ31/BĆ19
2 AĆ4 AĆ51/BĆ21
3 AĆ6 AĆ71/BĆ23
4 AĆ8 AĆ91/BĆ25
5 AĆ10 AĆ111/BĆ27
6 AĆ12 AĆ131/BĆ29
7 AĆ14 AĆ151/BĆ31
A = output t rminals
B = common t rminals
C = Pow r t rminals (CĆ34 thru 51 for 1794ĆTB3)
1AĆ1, 3, 5, 7, 9, 11, 13 and 15 ar conn ct d tog th r insid th modul to 24V dc common.
ATTENTION: Total current draw through the terminal
base unit is limited to 10A. Separate power connections to
the terminal base unit may be necessary.
Wiring to a 1794ĆTBN Terminal Ba e Unit
1. Connect individual output wiring (customer loads) to even numbered
terminals (0 thru 14) on row (B).
2. Connect customer load returns to odd numbered terminals (1 thru 15)
on row (C) as indicated in the table below.
3. Connect 24V dc return to terminal 16 on row (B).
4. If continuing the dc return bus to the next terminal base unit, connect
a jumper from terminal 33 on this base unit to terminal 16 on the next
base unit.
5. Connect +24V dc power to terminal 34 on row (C).
6. If continuing dc power to the next terminal base unit, connect a
jumper from terminal 51 (+24V dc) to terminal 34 on the next base
unit.
0246810121433
16
13 57 911131551
34
16, 0, 2, 4, 6,
8, 10, 12, 14, 33
34, 1, 3, 5, 7,
9, 11, 13, 15, 51 C
B
1794ĆTBN
16 33Ev n Numb r d T rminals 0 thru 14
34 51Odd Numb r d T rminals 1 thru 15

24V dc FLEX I/O Electronically Fused 8 Output Module 5
/!'&" .&*) 2 +,&' 
1794 TBN
Output Terminal Common Terminal
2 2
2 2
2 2
2 2
2 2
2 2
2 2
2 2
  $0$) )/(!$,$# */.+/. .$,(&) '-  .%,/  #" "*((*) .$,(&) '-  )# 
  *1$, $,(&) '- 2 )# 2 )# *## )/(!$,$# */.+/. "*((*) .$,(&) '-  .%,/ 
Indicators
   

2

B
ACD
      


A= Status Indicators () – yellow – show status of individual outputs.
B= Diagnostic indicators () – red – when lit, indicates fault
C= Insertable label for writing input designations
D= Reset button – press to reset fault
Resetting a Module Fault
Faults can be reset 3 ways:
•press the fault reset button
•toggle the output reset bit (write word 1, bit 08)
•cycle backplane power
The reset function resets all output fault bits simultaneously. Non-faulted
outputs remain unaffected during the reset
AB Drives

24V dc FLEX I/O Electronically Fused 8 Output Module6
Publication 1794Ć5.20- April 1999
Using the Fault Reset Button
When you press the manual reset button:
•the fault indicator for the faulted output turns off for about 1.2s (the
faulted output will not attempt to turn on during this delay)
•after the 1.2s delay, the faulted output attempts to turn on
•if the external condition causing the fault is corrected, the output will
remain on, the fault indicator is off, and the status indicator is on
Image Table Mapping
Decimal Bit
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
IW F7 F6 F5 F4 F3 F2 F1 F0 Reserved (see note)
W Not used FR 7 6 5 4 3 2 1 0
W2 Reserved
Where: IW = input word
W = output word
F = overload fault bits-1=fault present;0=nofault
= output data ( 0 corresponds to output 0, 1 corresponds to output 2, etc.)
FR = fault reset bit-1=reset output;0=nochange.
Note: The unused lower byte in read word 1 floats during operation. Do not use this byte for fault
status. See Programming" below.
Programming
If your program automatically checks for fault bits, bits 8 through 15 of
read word 1 must be masked. This is a sample program for a module at
rack address 1, group 0. Add similar rungs to your program.
MVM
MASKED M VE
Source:
Mask:
Destination:
I:010
FF00
N9:0
CMP
Compare
Expression
N9:0<>0
ut()
:000
This rung masked bits 8 thru 15.
This rung turns on output if a fault occurs.

24V dc FLEX I/O Electronically Fused 8 Output Module 7
Publication 1794Ć5.20- April 1999
          "
Number of utputs 8 (1 group of 8), nonĆisolated, sourcing
Module Location Cat. No. 1794ĆTB3, ĆTB3S, and ĆTBN Terminal Base
NĆstate Voltage Range 19.2V dc minimum
24V dc nominal;
31.2V dc maximum
utput Current Rating Maximum 2.0A per output
10A maximum per module (e.g. 8 outputs @ 1.25A, 5
outputs @ 2.0A, or similar output/ampere combinations
totaling 10A or less)
FFĆstate Voltage 31.2V dc maximum
NĆstate Current 1.0mA minimum per channel
2.0A maximum per channel
Surge Current 4A for 10ms, repeatable every 3 seconds (see chart)
FFĆstate Leakage 0.5mA maximum
NĆstate Voltage Drop 0.2V dc maximum
Isolation Voltage (minimum) 100% tested at 850V dc for 1s between user and system
No isolation between individual channels
utput Signal Delay1
ff to n
nto ff
0.1ms maximum
0.1ms maximum
Flexbus Current (maximum) 73mA
Power Dissipation 5.5W maximum @ 31.2V
Thermal Dissipation 18.8 BTU/hr @ 31.2V dc
Indicators (field side
indication, logic driven)
8 yellow status indicators;
8 red fault indicators
Keyswitch Position 2
 
External dc Power
Supply Voltage
Voltage Range
Supply Current
24V dc nominal
19.2 to 31.2V dc (includes 5% ac ripple)
80mA @ 24V dc
Dimensions Inches
(Millimeters)
1.8H x 3.7W x 2.1D
(45.7 x 94.0 x 53.3)
    ! 
AB Drives

24V dc FLEX I/O Electronically Fused 8 Output Module8
Publication 1794Ć5.20- April 1999
    ! ! !    "
Environmental Conditions
Operational Temperature
Storage Temperature
Relative Humidity
Shock Operating
Nonoperating
Vibration
0to55
oC (32 to 131oF)
-40 to 85oC (-40 to 185oF)
5 to 95% noncondensing
30 g peak acceleration, 11(+1)ms pulse width
50 g peak acceleration, 11(+1)ms pulse width
Tested5g@10-500Hz per IEC 68Ć2Ć6
Conductors Wire Size
Category
12 gauge (4mm2) stranded maximum
3/64 inch (1.2mm) insulation maximum
22
Agency Certification
(when product is marked) •CSA certified
•CSA Class I, Division 2, Groups A, B, C, D certified
•U listed
•CE marked for all applicable directives
1Off/on delay is time from a valid output on" signal to output energization. On/off delay is time from
a valid output off" signal to output deenergization.
2You use this conductor category information for planning conductor routing as
described in the system level installation manual.
0
5
10
15
20
0 1020304050
! ! ! ! !
"
With major offices worldwide.
World Headquarters,
AllenĆBradley,
1201 South Second Street,
Milwaukee, WI 53204 USA,
Tel: [phone]Ć2000 Fax: [phone]Ć4444
Publication 1794Ć5.20 - April 1999
Supersedes publication1794Ć5.20 - August 1996
PN955117-41A
Copyright 1999 AllenĆBradley Company, Inc. Printed in USA