Digital I/O Conversion Module
(Cat 1492-CM1771-LD008F)
I. Description
This Digital I/O Conversion system provides for the conversion of (1) 1771, 16 point I/O modules to be converted
to (2) 1756, 8 point I/O module and consists of the following:
(1) 1771 Modules (16pt) to (2) 1756 Module (8pt)
(1) Conversion Modules: 1492-CM1771-LD008F
(1) Cable: 1492-CONCAB005S1 (Table 2)
(1) Conversion Mounting Assembly: 1492-MUA… (Table 1)
This conversion is accomplished without the removal of any field wires from the existing 1771 Swing Arm. The
existing 1771 Swing Arm fits directly onto the edge connector of the 1492 Conversion Module. On one end of the
1492 Cable is (1) connector for the Conversion Module. On the other end are (2) Removable Terminal Blocks
(RTBs) for the (2) 1756 I/O modules, as shown in the photo below. The I/O signals are routed through the 1492
Conversion Module and the 1492 Cable to the appropriate terminals on the (2) 1756 I/O modules per the Wiring
Diagrams in Section VI. As standard, both portions of the 1492 Cables are 0.5M long, but we also offer a 1.0M
cable length. Refer to the footnotes in Table 2, Section III for further details.
Cable
1492-CONCAB005S1
Conversion Compatibility
and Product I.D. Label
37-Pin Connector for cable
1492-CONCAB005S1
1492-CM1771-LD008F Conversion Module
WARNING
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
Printed in U.S.A.
De-energize and lockout any and all power to all I/O field devices connected to the A-B 1771 I/O
chassis, and the power to the 1771 I/O chassis itself. Ensure all power is de-energized and locked out
to any device in the control cabinet where the conversion is to be performed. Ensure work is
performed by qualified personnel.
II. Installation
The 1492 Conversion Modules must be installed in a 1492 Conversion Mounting Assembly (see Table 1 below). A
complete System Installation Manual ships with the 1492 Conversion Mounting Assembly.
1) Determine the quantity of each type of 1771 I/O modules used in the 1771 I/O Chassis to be converted.
2) Select the applicable 1492 Conversion Modules from Table 2, Section III.
3) Review the Max Slots for I/O and Chassis Width data from the Table 1 below.
4) Select a 1756 I/O Chassis which has enough I/O Slots.
NOTE: (2) I/O slots are required in the 1756 Chassis for conversions where (1) 1771 I/O module converts to (2) 1756 I/O
modules.
5) Select the 1492 Conversion Mounting Assembly which has enough Conversion Module slots.
NOTE: (2) Conversion Module slots are required in the 1492 Conversion Mounting Assembly for conversions where (2)
1771 I/O module convert to (1) 1756 I/O modules.
NOTE: The 1492 Conversion Mounting Assembly has the same Height & Width foot-print as the 1771 Chassis and is
designed to use the same mounting hardware. The combined Depth of the 1492 Conversion Mounting Assembly with the
1756 Chassis mounted on top is 10.25 inches (Controller w/key) or 10.0 inches (Controller w/o key). Dimension drawings
are included in the System Installation Manual that ships with the 1492 Conversion Mounting Assembly.
Table 1: Bulletin 1771 to 1756 Chassis Conversion
1771 Chassis
Cat. No.
Max
Slots
for
I/O
1771-A1B
4
1756 Chassis
Chassis Width
without
Power
Supply
with
Power
Supply
9.01
12.61
14.01
17.61
Conversion Mounting Assembly
Cat. No.
Max
Slots
for
I/O
Chassis
Width
Cat. No.
Max Slots
for
Conversion
Modules
Chassis
Width
1492-MUA1B-A4-A7
4
9.01
1756-A4
3
10.35
1756-A7
6
14.49
1756-A7
1756-A10
6
9
14.49
19.02
1492-MUA2B-A7-A10
8
14.01
1771-A2B
8
1771-A3B1
12
19.01
1756-A10
1756-A13
9
12
19.02
23.15
1492-MUA3-A10-A13
12
19.01
1771-A4B
16
24.01
1756-A13
1756-A17
12
16
23.15
29.06
1492-MUA4-A13-A17
16
24.01
Foot Notes:
1771-A3B is not listed as it is used for 19 inch wide instrumentation panels.
Notice that the 1756 Chassis Width sometimes exceeds the 1771 Chassis Width, with or without the Power Supply. The
Cover-Plate of the 1492 Conversion Mounting Assembly allows the 1756 Chassis to be Left justified, Right justified or
Centered. A complete System Installation Manual ships with the 1492 Conversion Mounting Assembly.
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
(2)
III. Compatibility
1771
Digital I/O Module
1756
Digital I/O Module
1771-OBD
1756-OC8 (Qty 2)
1492
Conversion Module
1492-CM1771-LD008F
1492
Cable
1492-CONCAB005S1
Foot Notes:
To understand any issues concerning I/O module compatibility, refer to the Installation Manuals for the specific 1771
and 1756 I/O modules involved. The (2) 1756 modules must be located directly next to each other in the 1756
chassis.
The 3 numbers indicate the cable length of the 1492 Cable. Recommended cable length of 0.5M is shown.
Alternative cable lengths are as follows:
1.0M = 1492-CONCAB010S1
The "F" at the end of the 1492 I/O Conversion Module Catalog Number indicates it is fused to match the functionality
of the 1771 module being replaced.
IV. Conversion Module Specifications
(Operating specifications are when installed in the Conversion System base / cover-plate assembly)
Specification
Value
Dimensions
11.81 in. (height) x 4.38 in. (depth) x 1.5 in. (width)
300 mm. (height) x 111.25 mm (depth) x 38.1 mm (width)
Approximate Shipping Weight
265.4 g (0.58 lbs) (includes carton)
-40 to +85°C (-40 to +185°F)
0 to 60°C (32 to 140°F)
5 to 95% at 60°C (non-condensing)
Storage Temperature
Operating Temperature
Operating Humidity
Shock
Non operating
Operating
Operating Vibration
Maximum Operating Voltage
Max. Module Operating Current
Per Point:
Per Module:
50g
30g
2g at 10 to 500Hz (Agrees with 1756 I/O module specifications)
60 Vdc
2 Amps
8 Amps
NOTICE
Refer to the Wiring Diagram(s) for
current limits for a specific configuration.
Fusing
One, 10 Amps (maximum current based on conversion components)
Agency Certifications
UL Classified: Under UL File Number E113724
CSA
CE: compliant for all applicable directives
Pollution Degree
2
Environmental Rating
IP20
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
(3)
V. Fuse Installation and Replacement
The 1492-CM1771-LD008F conversion module has one mechanical fuse holder with the fuse located on the circuit
board inside the modules plastic case. The following explains how to replace the fuse:
1) Remove the 4 screws that hold both halves of the conversion module case together (refer to the following
Figure A).
Figure A
2) Disassemble both case halves so you can access the module’s circuit board. Remove and replace the fuse
(refer to the below Figure B).
Fuse holder and Fuse
Figure B
3) Reassemble the two case halves to the circuit board and replace the four screws that hold the case together
(Do NOT over torque the screws (Maximum torque is 5.0 in-lbs.)
NOTES:
1) For module operation a fuse must be inserted into the fuse holder
2) Physical Fuse Size: 2AG
3) Possible Fuse Supplier: LittelFuse (Part Number: 225010P)
4) Maximum Fuse Current rating based on Conversion System Components: 10.0 Amps
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
(4)
Conversion: 1771-OBD (1) to 1756-OC8 (2)
VI. Wiring Diagrams
There are several key application considerations and system specifications (bottom of drawing) when
using these components (conversion module, cable and input module). Read and understand these
considerations before installation.
+
-
LOAD
DC(+)
DC(+)
DC(+)
DC(+)
Output 00
Output 01
Output 02
Output 03
Output 04
Output 05
Output 06
Output 07
Output 10
Output 11
Output 12
Output 13
Output 14
Output 15
Output 16
Output 17
A
B
C
D
00
01
02
03
04
05
06
07
10
11
12
13
14
15
16
17
DC(-)
E
Cable
1492-CONCAB005S1
1756-OC8
1
Black
2
DC-0(+)
2
White
1
OUT-0
3
Red
3
OUT-1
4
Green
5
OUT-2
5
Orange
7
OUT-3
9
4
6
8
10
12
14
16
18
11
13
15
17
19
20
RTN OUT-0
DC-0(+)
DC-0(+)
DC-0(+)
RTN OUT-0
DC-1(+)
DC-1(+)
DC-1(+)
DC-1(+)
OUT-4
OUT-5
OUT-6
OUT-7
RTN OUT-1
RTN OUT-1
6
7
8
9
10
11
12
13
14
15
16
17
Blue
18
Orange/Red
19
20
21
22
23
Blue/Red
White/Black
Red/Black
Green/Black
Orange/Black
Blue/Black
Black/White
Red/White
Green/White
Blue/White
Black/Red
White/Red
MODULE A
Conversion Module
1492-CM1771-LD008F
1756-OC8
24
25
26
27
28
29
30
31
32
33
34
35
36
37
1771-WH, WHF, WHFB Swing Arm
From 1771-OBD
Red/Green
Orange/Green
Black/White/Red
White/Black/Red
Red/Black/White
Green/Black/White
Orange/Black/White
Blue/Black/White
Black/Red/Green
White/Red/Green
Red/Black/Green
Green/Black/Orange
Orange/Black/Green
Blue/White/Orange
Black/White/Orange
White/Red/Orange
White/Red/Blue
2
1
3
5
7
9
4
6
8
10
12
14
16
18
11
13
15
17
19
20
DC-0(+)
OUT-0
OUT-1
OUT-2
OUT-3
RTN OUT-0
DC-0(+)
DC-0(+)
DC-0(+)
RTN OUT-0
DC-1(+)
DC-1(+)
DC-1(+)
DC-1(+)
OUT-4
OUT-5
OUT-6
OUT-7
RTN OUT-1
RTN OUT-1
MODULE B
WARNING
Conversion Module Installation and Application Considerations
This Bul. 1492 cable consists of a cable wired to two 1756-OC8 RTB. Recommended cable lengths of 0.5M or 1.0M (005=0.5M,
010=1.0M). See table 2 for other lengths.
The 1771-OBD module output current limits versus 1756-OC8 limits are as follows:
a) Current/Point
b) Current /Module
c) Surge Current /Point
1771-OBD
2A
8A
4A for 10ms
1756-OC8 w/ 1492-CONCAB005S1
2A
8A
4A for 10ms
The 1771-OBD has a single 10A, 250V rectifier fuse (1/4 x 1 1/4 inch ). The 1756-OC8 is NOT fused ,as such a
2AG fuse clip and 10A fuse is provided on the 1492-CM1771-LD008F conversion module.
The 1771-OBD is rated 10V to 60V DC. The 1756-OC8 is rated 30V to 60V DC. If the load source voltages is less
than 30V DC, then use 1756-OB16E with the 1492-CM1771-LD006 conversion module.
This configuration uses two(2) 1756-OC8 output modules to replace a single 1771-OBD output module. This may require
the use of a larger 1756 I/O chassis and conversion mounting assembly. Ensure there is sufficient panel space to allow for
this possibility.
Refer to your 1771-OBD and 1756-OC8 Installation Manual wiring schematics and diagrams for more details. Ensure
1756 output module ratings are not exceeded.
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
[Reference Doc: 41170-937 (Version 01)]
(5)
PN-114280
DIR 10000060091 (Version 01)
Publication 1492-IN038B-EN-E
Printed in U.S.A.
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