PN-40377
DIR 10000045373
(Version 00)
Printed in U.S.A.
VI. Appendix A
1771 chassis to 1756 Chassis Conversion System Selection Process
1) Determine the number of 1771 I/O modules used in the 1771 I/O Chassis to be converted to 1756. NOTE: In some
cases two 1756 modules may be required for one 1771 module. Select the applicable 1492 conversion modules from the
Digital and Analog Conversion Selection Table Matrix.
2) Review the Max Slots for I/O and Chassis Width data from the below table, and select a 1756 I/O Chassis which meets
your conversion needs from Step 1. Ensure the information from the I/O Conversion module tables are reviewed first.
3) Once the 1756 Chassis is selected, select the Conversion Assembly. The Conversion Assembly has the same dimen-
sional foot-print as the 1771 chassis and can use the same mounting hardware. The assembly consists of a base-plate
to hold the conversion modules and a cover-plate to protect the modules and to mount the selected 1756 chassis. The
combined depth of the conversion assembly with the 1756 chassis mounted is 10.25 inches (Controller w/key) to
10.0 inches (Controller w/o Key).
Foot Notes:
1771-A3B is not listed as it is used for 19 inch wide instrumentation panels
Two 1771 width dimensions are provided as some PLC-5 processors have integrated power supplies. Dimension w/PS
includes -P1, -P2, etc. Notice that the width dimension of some 1756 chassis exceed the width of the 1771 chassis with
or without the power supply. Cover-plate chassis mounting design allows the excess 1756 chassis width to be evenly
distributed to both sides, or excess to right or left. Carefully consider this in the conversion
1756-A4 may work in a 1771-A1B application if 4 or less I/O slots were used. Conversion cover-plate is capable to
mount -A4 or -A7
1756-A7 may work in a 1771-A2B application if 6 or less I/O slots were used. Conversion cover-plate is capable to
mount -A7 or -A10
1756-A10 may work in a 1771-A3B1 application if 10 or less I/O slots were used. Conversion cover-plate is capable to
mount -A10 or -A13
1756-A13 may work in a 1771-A4B application if 13 or less I/O slots were used. Conversion cover-plate is capable to
mount -A13 or -A17
Max Slots for I/O
4
-A1B w/o
PS
4
-A1B
w/PS
3
6
8
8
6
9
12
-A13
(5)
12
-A3B1
-A10
-A7
(4)
-A2B
w/PS
-A2B w/o
PS
-A7
-A4
(3)
16
-A17
(6)
16
-A4B
Chassis Width
(2)
Conversion Assembly
Chassis Parameter
(1)
1756 Equivalent
Chassis
1756 Equivalent
Chassis
24.01
29.06
23.15
19.01
19.02
9.01
12.61
10.35
14.49
14.49
14.01
17.61
1771 Chassis
1771 Chassis
1771 Chassis
1492-MUA1B-A4-A7
1492-MUA2B-A7-A10
1492-MUA3-A10-A13
1492-MUA4-A13-A17
1771 Chassis
1756 Equivalent
Chassis
1756 Equivalent
Chassis