Allen-Bradley 1756-CNB - Page 29

Publication 1756-UM523F-EN-P - December 2006
Design the System 29
ControlLogix Redundancy Requirements and Recommendations (Continued)
1757-SRCx cable is available in
1 m (3 ft), 3 m (9 ft), 10 m (30 ft), 50 m
(150 ft), and 100 m (300 ft) lengths.
L
•
•
•
E
N
B
T
S
R
M
Redundant
Chassis A
Redundant
Chassis B
No Other Modules
1756-CNB/D/E or 1756-CNBR/D/E module or modules:
• 1-5 in each redundant chassis.
•≤ 5 total communication modules (CNBs, ENBTs, and
EWEBs) in each redundant chassis.
• Keep CPU usage ≤ 75%.
• Allocate 2 consecutive node addresses for each set of
partner CNB modules (one in each chassis).
• Assign each partner CNB module to the same node
address.
• Assign the higher node addresses in the system to the
CNB modules in the redundant chassis.
1757-SRM module:
• Only 1 in each redundant chassis
• Uses 2 slots
ControlLogix5555, ControlLogix5561, ControlLogix5562, or
ControlLogix5563 controllers:
• Same type of controller throughout the chassis.
• If ControlLogix5555, then 1 or 2 controllers in each
redundant chassis.
• If ControlLogix5561, ControlLogix5562, or
ControlLogix5563, then only 1 controller in each
redundant chassis.
• Enough memory for 2 copies of all data.
• 7 connections for redundancy.
C
N
B
L
•
•
•
E
N
B
T
S
R
M
No Other Modules
C
N
B
Same Size of Chassis
Identical Modules:
• Same Slot Number
• Same Catalog Number, Series, and Revision
• Same Memory Size (controller)
1756-ENBT or 1756-EWEB modules:
• 1- 2 in each redundant chassis.
•≤ 5 total communication modules (CNBs and ENBTs) in each
redundant chassis.
• For 1756-ENBT modules, catalog revision must be greater than
or equal to E01 (E01, E02, …, F01). See the side of the module
or its box.
• Requires RSLinx software, version 2.50.