AC/DC (120V) Input Module Cat. No. 1771-IAD Series C Installation Instructions

AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Installation Instructions
To The Installer
This document provides information on:
important pre-installation considerations
power supply requirements
initial handling procedures
installing the module
using the indicators for troubleshooting
module specifications
The 1771-IAD Series C module is compatible with all chassis except the
1771-A1, 1771-A2 and 1771-A4 chassis. Make sure no other input module
or single card block transfer module is placed in the same module group
when using 2-slot addressing. Any discrete output module may be used
within the same module group.
Power Requirements
Your module receives its power through the 1771 I/O chassis backplane
from the chassis power supply. The module requires 195mA from the
output of this supply. Add this to the requirements of all other modules in
the I/O chassis to prevent overloading the chassis backplane and/or chassis
power supply.
Initial Handling
The ac/dc input module is shipped in a static-shielded bag to guard against
electrostatic discharge damage. Observe the following precautions when
handling the module.
ATTENTION: This module is equipped with a plastic cover
that is unique to all assembly numbers with the prefix 961440.
(This part number is located near the backplane edge connector
pins on the component-side of the circuit board.) Do not use this
plastic cover on any other module.
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Electrostatic Discharge Damage
ATTENTION: Under some conditions, electrostatic discharge
can degrade performance or damage the module. Observe the
following precautions to guard against electrostatic damage.
Wear an approved wrist strap grounding device, or touch a grounded
object to discharge yourself before handling the module.
Do not touch the backplane connector or connector pins.
If you configure or replace internal components, do not touch other circuit
components inside the module. If available, use a static-free work station.
When not in use, keep the module in its static-shielded bag.
Installing Your Module
In this section, we tell you how to:
change the delay time jumper
key your I/O chassis
install your module
make your wiring connections
Changing the Delay Time Jumper
Your module is equipped with an adjustable delay time jumper. Use the
jumper to select between two input channel delay times. The delay time
you choose applies to all sixteen of the module’s channels.
Use this delay time:
If you want:
to detect typical input readings
to prevent detection of false inputs in high-noise environments
The module is shipped with the delay time jumper preset to 5ms. To
change the delay time jumper to 20ms, do the following:
Locate the delay time jumper selection plug at the top-right edge of
the module circuit board, as shown in the following figure.
Use your finger to slide the jumper off the 5ms position (the middle
post and the right post).
Carefully reposition the jumper by sliding it onto the 20ms position
(the middle post and the left post).
Top-right edge of circuit board
Delay Time Jumper
(shown in preset 5ms
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Keying Your I/O Chassis
Use the plastic keying bands, shipped with each I/O chassis, to key the I/O
slots to accept only this type of module.
The module circuit board is slotted in two places on the rear edge. The
position of the keying bands on the backplane connector must correspond
to these slots to allow insertion of the module. You can key any connector
in an I/O chassis to receive this module except for the left-most connector
reserved for adapter or processor modules. Place keying bands between the
following numbers labeled on the backplane connector:
Between 10 and 12
Between 14 and 16
You can change the position of these keys if system redesign and rewiring
makes insertion of a different module necessary.
Installing Your Input Module
To install the ac/dc input module in your 1771 I/O chassis, follow the steps
listed below.
ATTENTION: Remove power from the 1771 I/O chassis
backplane and field wiring arm before removing or installing an
I/O module.
Failure to remove power from the backplane or field wiring
arm could cause module damage, degradation of
performance, or injury.
Failure to remove power from the backplane could cause
injury or equipment damage due to possible unexpected
Turn off power to the I/O chassis.
Place the module in the plastic tracks on the top and bottom of the
slot that guides the module into position.
Do not force the module into its backplane connector. Apply firm,
even pressure on the module to seat it properly.
Snap the chassis latch over the top of the module to secure its
Connect the field wiring arm to the module.
Make wiring connections to the field wiring arm as indicated in
Figure 1.
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Connecting Wiring to the Input Module
Connections to the input module are made to the field wiring arm (cat. no.
1771-WH) shipped with the module. Attach the field wiring arm to the
pivot bar on the bottom of the I/O chassis. The field wiring arm pivots
upward and connects with the module so you can install or remove the
module without disconnecting the wires.
Figure 1
Connection Diagram
ac/dc High
Terminal A
Terminal B
Terminal C
Terminal D
Input 00
Input 01
Input 02
Input 03
Input 04
Input 05
Input 06
Input 07
Input 10
Input 11
Input 12
Input 13
Input 14
Input 15
Input 16
Input 17
Terminal E
ac/dc Low
Field Wiring Arm
Cat. No. 1771-WH
(Actual wiring runs in this direction.)
Connect one terminal of your 2-wire input device to terminals 00 thru 17
(Figure 1). Connect L1 (high) ac/dc line to the other terminal of your input
devices. Connect terminal E to the L2 (low) ac/dc return. Terminals A thru
D are not used. Use stranded 14 or 16 gauge wire to minimize the voltage
drop over long cable distances.
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Important: You can use an AC (120V) Output Module (cat. no.
1771-OAD) to directly drive terminals on an AC/DC (120V) Input Module
(cat. no. 1771-IAD) (Figure 2).
Figure 2
Driving a 1771-IAD Module with a 1771-OAD Module
AC (12-120V)
Output Module
(Cat. No. 1771-OAD)
AC/DC (120V)
Input Module
(Cat. No. 1771-IAD)
120V ac High
Note: 1771-OAD output voltage
range is 12-138V ac. However,
the on-state voltage range of the
1771-IAD is 79-138V ac.
ac Low
You can also use a 1771-OA Output module to drive an AC/DC (120V)
Input Module (cat. no. 1771-IAD) but you must connect one of the
following between the output terminal and L2 (common) (Figure 3).
2500 ohm, 10W resistor
RG-1676-1 Electrocube (San Gabriel, California)
Use the same ac power source to power both modules to ensure proper
phasing and prevent module damage.
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Figure 3
Driving a 1771-IAD Module with a 1771-OA Module
AC (120V)
Output Module
(Cat. No. 1771-OA)
AC/DC (120V)
Input Module
(Cat. No. 1771-IAD)
ac High
2500 ohm 10W
Note: 1771-OA output voltage
range is 92-138V ac. However, the
on-state voltage range of the
1771-IAD is 79-138V ac.
Interpreting the Status
ac Low
The front panel of your module contains one green module active
indicator, and 16 red status indicators (figure 4).
When the green module active indicator lights, the rack power supply has
properly established 5Vdc. To properly interpret the red status indicators,
the module active indicator must be lit.
The red status indicators are provided for system logic side indication of
individual inputs. When a red indicator lights, voltage is present on the
terminal. The module transfers this information to the backplane for the
processor to read. See ‘‘Troubleshooting” for a description, probable cause,
and recommended action to take for common faults based on
indicator responses.
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Figure 4
Status Indicators
Module Active Indicator (green)
00 10
01 11
02 12
03 13
04 14
05 15
06 16
07 17
00 to 17 Status Indicators (red)
Use this table to help you interpret the 1771-IAD status indicators and to
troubleshoot module and system faults.
Indicator Status (color)
Description of Fault or System Status
Action to Take
Module active ON (green)
Normal Indication
Module active ON (green) and
Input status ON (red)
Check for voltage on terminal.
If voltage is present, take no action. If no
voltage is present, replace the module.
Module active ON (green) and
Input status OFF
Input devices not functioning properly or
faulty input circuitry on module.
1. Check input devices.
2. If input devices are OK, replace module.
No voltage on terminal.
Not valid unless module active indicator is
on; when active is off, indicators do not
represent processor status.
1. Check chassis power supply and module
input power.
2. If power supplies are OK, replace module.
Module active OFF and
Input status ON (red) or OFF
Installation Instructions
AC/DC (120V) Input Module
Cat. No. 1771-IAD Series C
Inputs per Module
Module Location
1771 Series B or later I/O chassis, 1771-AM1, -AM2 chassis
Nominal Input Voltage
120V ac @ 50/60Hz; 125V dc
Nominal Input Current
9.9mA @ 120V ac 60Hz; 8.7mA @ 120V ac 50Hz; 2.56mA @ 125V dc
On-state Voltage Range
79V to 138V ac or dc
Minimum On-state Current
5.95mA @ 79V ac 60Hz; 1.5mA @ 79V dc
Maximum Off-state Voltage
43V ac or dc
Maximum Off-state Current
Input Impedance
3.0mA @ 43V ac 60Hz; 0.8mA @ 43V dc
11.2K ohms @ 60Hz (0.18 microfarad in parallel with 47K ohms, in series with 820 ohms)
Peak Inrush Current
Input Signal Delay Off to On
On to Off
Power Dissipation
Inrush = VPS/820 ohm, where VPS = customer supply peak voltage
5ms (+3ms) or 20ms (+5ms) @ 120V ac 60Hz selectable
3ms (+.1ms) or 10ms (+1ms) @ 120V dc selectable
25ms (+5ms) @ 120V ac or dc
8.8 Watts (max.), 1.0 Watts (min.)
Thermal Dissipation
30.1 BTU/hr (max.), 3.42 BTU/hr (min.)
Backplane Current
195mA @ 5V
Isolation Voltage
Environmental Conditions
Operational Temperature
Storage Temperature
Relative Humidity
Wire Size
Field Wiring Arm
Wiring Arm Screw Torque
Tested at 2500V dc for 1 second per UL508 & CSA C22.2 #142
0o to 60oC (32o to 140oF)
-40o to 85oC (-40o to 185oF)
5 to 95% (without condensation)
14 gauge stranded maximum
3/64 inch insulation maximum
Between 10 and 12
Between 14 and 16
Catalog Number 1771-WH
7-9 inch-pounds
1 Refer to publication 1770-4.1, Programmable Controller Wiring and Grounding Guidelines.
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Supersedes Publication 1771-2.73 September 1992
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