Allen-Bradley 1769-L36ERM CompactLogix 5370 Controller

The Allen-Bradley 1769-L36ERM is a high-performance Programmable Automation Controller (PAC) belonging to the CompactLogix 5370 L3 family. Engineered to deliver scalable, integrated control across a wide array of industrial applications, this processor features integrated motion capabilities over EtherNet/IP alongside a 3 MB user memory footprint. It allows standard control, distributed I/O, and multi-axis synchronized motion to run within a unified, rackless system architecture.

Hardware Specifications

Device Level Ring (DLR) and CIP Motion Integration

The dual embedded Ethernet ports on the 1769-L36ERM act as an integrated two-port switch supporting Device Level Ring (DLR) network topologies. This provides physical media redundancy, keeping the controller connected to distributed I/O banks and servo drives even if a single point in the network ring breaks.

Motion control is executed using CIP Motion (Common Industrial Protocol over EtherNet/IP). Instead of relying on proprietary hardware modules, the 1769-L36ERM transmits deterministic time-synchronization data packets using IEEE 1588 CIP Sync. This enables precise positioning, speed, and electronic gearing commands across up to 16 synchronized axes of Kinetix servo drives on standard Ethernet cabling.

Frequently Asked Questions

Q: Does the 1769-L36ERM require an external backup battery to maintain user memory?

A: No. The CompactLogix 5370 series utilizes an embedded energy storage module that generates sufficient internal hold-up power during an unexpected outage to automatically flash the volatile user application memory into non-volatile onboard memory.

Q: What is the maximum distance or configuration limit for local 1769 expansion banks?

A: The 1769-L36ERM can support up to 30 expansion modules across a maximum of three total banks (one local chassis plus two expansion banks). Each expansion bank requires a separate 1769 power supply and communication expansion cables (e.g., 1769-CBL). Ensure the power supply distance rating for individual modules is not exceeded (typically a maximum of 8 slots from the power supply).

Q: Is the embedded USB port intended for continuous HMI runtime communication?

A: No. The integrated front-panel USB 2.0 port is designated strictly for temporary firmware flashing, initial configuration adjustments, and application uploads/downloads using Studio 5000 Logix Designer. It is not rated for permanent network infrastructure or industrial runtime data collection.

Field Installation Guidelines

• System Expansion Power Distribution: When laying out local 1769 I/O modules to the right of the controller, verify that the total backplane current draw does not exceed the capacity of the local power supply. Place higher current-consumption modules closer to the power source.
• Firmware Upgrade Sequencing: Before commissioning, connect via the USB interface and apply the target firmware revision utilizing ControlFLASH or ControlFLASH Plus software to match the major and minor software versions of your Studio 5000 Logix Designer programming project.
• DIN Rail and Panel Grounding: Mount the unit onto an industry-standard 35 mm DIN rail or secure it directly via panel-mount screws. Ensure the zinc-plated steel DIN rail is properly grounded to the industrial enclosure ground plane to minimize electrical noise path interference.