Description
The 1769-L33ER is an incredibly popular workhorse controller from Allen-Bradley’s (Rockwell Automation) CompactLogix 5370 L3 processor family. It is widely used in mid-sized industrial automation projects, machine control, and process lines.
Unlike the older 1769-L32E/L35E “shoebox” generation that relied on lithium batteries and serial ports, the L33ER brought modern, capless/battery-free energy storage and embedded dual-port Ethernet to the 1769 platform.
Core Technical Specifications
- User Memory: 2 MB (volatile memory used for data tables and control logic).
- Communication Interface: Dual Ethernet ports and 1 integrated USB type-B port (solely for local firmware flashing, programming, and configuration updates).
- Network Capabilities: Built-in Device Level Ring (DLR) topology support. This allows you to chain your devices in a ring network configuration so that if one Ethernet cable is cut, communication continues from the opposite direction without dropping the machinery.
- Network Node Limit: Supports a maximum of 32 EtherNet/IP nodes.
- Local I/O Capacity: Can control up to 16 local 1769 Compact I/O modules directly on its right side, spanning up to 3 physical expansion banks.
- Task Architecture: Can run 32 separate periodic or continuous application tasks, with up to 100 executable programs per task.
- Programming Environment: Requires RSLogix 5000 (v20) or Studio 5000 Logix Designer (v21 and higher).
Crucial Hardware Facts (The “Gotchas”)
🔋 Battery-Free Backup: The 1769-L33ER does not use a lithium battery. Instead, it utilizes an internal supercapacitor to hold back system data temporarily during an unexpected power drop while it writes the active memory payload onto its non-volatile memory (it ships standard with a 1 GB 1784-SD1 Secure Digital card inserted under the front door flap).
🚫 No Integrated Motion: Note the exact part number. The standard L33ER handles standard discrete logic and process control loops. If your machine requires coordinated CIP motion over Ethernet (for controlling Kinetix servo drives directly via logic profiles), you would need the 1769-L33ERM variant.
Lifecycle Status Warning
Rockwell Automation classifies the 1769-L33ER as an Active Mature product. This means that while units are still supported and available, the product family has been succeeded by the faster, more secure CompactLogix 5380 platform (which uses the 5069 I/O footprint). If you are specifying a brand-new control system today, it is highly recommended to shift over to a 5380 controller to ensure maximum lifespan for your hardware.
