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Allen Bradley ControlLogix Controllers


Several options are available, including standard controllers, GuardLogix safety controllers, and ControlLogix-XT extreme temperature controllers. User memory options range from 2 MB to 32 MB.

You will need to select the appropriate controller with sufficient memory to operate your system. If there is any doubt, always select the next larger memory option. You'll also be choosing optional memory cards as needed. Controllers can be placed in any slot of a ControlLogix chassis, and multiple controllers can be mounted in the same chassis. Multiple controllers communicate with each other but can operate independently. Refer to the following tables for specifications. Controller USB ports are intended for temporary local programming. USB ports are not suited for permanent connections or hazardous locations.

Part NumberDescriptionUser Memory
1756-L71ControlLogix Controller
with 1 built-in USB Port
2 MB
1756-L724 MB
1756-L738 MB
1756-L7416 MB
1756-L7532 MB
1756-L61ControlLogix Controller
with 1 built-in RS-232 Port
2 MB
1756-L624 MB
1756-L638 MB
1756-L6416 MB
1756-L6532 MB
1756-L63XTControlLogix XT Controller for
Extreme Temperatures/Extreme Environments
8 MB
1756-L73XT8 MB
1756-L61SGuardLogix Safety Controllers2 MB Standard/1 MB Safety
1756-L62S4 MB Standard/1 MB Safety
1756-L63S8 MB Standard/3.75 MB Safety
1756-L72S4 MB Standard/2 MB Safety
1756-L73S8 MB Standard/4 MB Safety
1756-LSPGuardLogix Safety Partner/Use with 1756-L6xS GuardLogix Controllers
1756-L7SPGuardLogix Safety Partner/Use with 1756-L7xS GuardLogix Controllers

ControlLogix Controllers Standard Features

Feature1756-L61, L62, L63, L64, L651756-L71, L72, L73, L74, L75
Controller Tasks32 Tasks, 100 Programs/Task, Event Tasks: All Event Triggers
Built-In Communication Ports(1) RS-232 Serial Port(1) USB Port
Communication OptionsEtherNet/IP, ControlNet, DeviceNet, Data Highway Plus, Remote I/O, SynchLink, Third Party Process and Device Networks
Maximum Controller Connections250500
Connections per Network Module100 ControlNet (1756-CN2/A); 40 ControlNet (1756-CNB;
256 EtherNet/IP, 128 TCP (1756-EN2x); 128 EtherNet/IP, 64 TCP (1756-ENBT)
Controller RedundancyFull Support
Integrated MotionEtherNet/IP Connection; SERCOS; Analog Options: Encoder, LDT, SSI
Programming LanguagesRelay Ladder; Structured Text; Function Block; SFC
Optional Memory Cards1784-CF128: 128 MB1784-SD1: 1 GB; 1784-SD2: 2 GB

Redundant ControlLogix Controllers

All ControlLogix controllers support controller redundancy. A redundant controller system requires two 1756 Chassis per redundant system with these identical features:

  1. Total number of slots
  2. Modules in same slots in each chassis
  3. Redundancy firmware in each chassis
  4. Two additional ControlNet Nodes outside the redundant chassis pair
  5. One 1756-RM Redundancy Module per chassis to support one 1756-L64 or L65 controller or one 1756-RM to support two 1756-L71, L72, L73, L74, L75, L61, L62 or L63 controllers
  6. Maximum seven communication modules. Choose from 1756-CN2/B, CN2R/B, EN2T, or EN2F Modules
  7. One 1756-RMCx cable


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