1769-L31ER-NSEAllen-Bradley CompactLogix 5370 L3 Controller

Allen-Bradley 1769-L31ER-NSE CompactLogix Processor Module

The Allen-Bradley 1769-L31ER-NSE, also cataloged as the 1769-L31 Programmable Automation Controller, operates as a dedicated hardware component for industrial automation and motion processing execution within CompactLogix network platforms. The hardware implements a specialized No Stored Energy (NSE) architecture that drops residual energy to less than 200 uJ per component upon power disconnection, eliminating spark hazards in gaseous or volatile environments. Featuring dual Ethernet ports configured for Device Level Ring (DLR) topologies, the module coordinates up to 16 motion axes over industrial networks while executing program logic without internal battery backup systems.

Hardware Specifications

EtherNet/IP Deterministic Networks and Firmware Flash Compatibility

The processor regulates data packet delivery across EtherNet/IP deterministic networks by executing synchronous data transmissions through its integrated dual-port switch. System architectures utilize the embedded Device Level Ring (DLR) protocol to maintain network connectivity and uptime if a single physical line break occurs. The processing core matches local I/O modules via standard 1769 backplane bus communication velocity parameters, allowing deterministic I/O density scaling across connected expansion racks. To ensure operational consistency, the module requires strict verification of firmware flash compatibility via ControlFLASH utility software, allowing secure updates over the active EtherNet/IP interface or local USB channels before commissioning the unit.

Frequently Asked Questions

Q: How does the No Stored Energy (NSE) architecture affect data retention when the controller loses main electrical power?

A: Because the NSE design eliminates internal lithium batteries and high-capacity capacitors to prevent sparking, the controller does not maintain long-term internal RAM storage on power loss. It writes active project data directly to the non-volatile 1 GB SD card during a controlled shutdown sequence to preserve the logic application.

Q: Can this processor module be inserted into an active 1769 backplane chassis while power is applied?

A: No. The CompactLogix 5370 L3 framework does not allow hot-swapping or Removal and Insertion Under Power (RIUP). Attempting insertion or removal operations while the backplane power supply rail is active will damage the processing circuits and trigger major system errors.

Field Installation Guidelines

• Chassis Attachment and Mounting Alignment: Mount the processor unit onto an EN 50022 compliant 35 mm DIN rail or secure it to the enclosure panel using the integrated mounting tabs. Verify that all neighboring 1769 Compact I/O modules seat properly via the built-in tongue-and-groove guides before latching the bus connectors.
• Wiring Configurations and Terminations: Connect field interfaces using 90 deg C rated copper wire. Limit solid wire selections to sizes between 22-14 AWG and stranded wire options to 22-16 AWG. Strip insulation back according to the specifications designated for the 1769-RTBN18 replacement terminal block.
• Electrical Grounding and Shield Layouts: Terminate the controller grounding lug directly to a low-impedance functional earth ground bar on the central control panel. Route all EtherNet/IP and communication lines in isolated wireways away from high-voltage AC conductors or variable frequency drive cables to suppress electromagnetic noise cross-talk.