Product Overview
When a water treatment skid in West Texas lost its legacy controller, the maintenance team faced a hard deadline: restore 24 discrete inputs and 16 relay outputs without redesigning the panel. The Allen-Bradley 1762-L40AWAR MicroLogix 1200 PLC solved that problem. It packs embedded I/O, serial communication, and a compact footprint into one controller that fits existing enclosures and wiring schemes.
This Rockwell Automation controller runs on 120 to 240V AC input power and draws 82 VA. Its 24 inputs accept 120V AC signals with sink or source wiring, while 16 relay outputs handle volt-free switching. The 1762-L40AWAR also includes one 8-pin mini-DIN serial port and one programming port, supporting DF1, DH-485, ASCII, and MODBUS protocols.
Technical Specifications
I/O and Power
The 24 discrete inputs support both sink and source configurations, giving panel builders flexibility during retrofit. Inputs 0 through 3 have an ON state range of 14 to 24 VDC, while inputs 4 and higher switch ON between 10 and 24 VDC. The OFF state stays between 0 and 5 VDC, with minimum OFF state leakage of 1.5 mA.
The 16 relay outputs are contact type, rated for 24-125 VDC or 120-240 VAC. They carry a minimum 10A load and deliver 20,000,000 mechanical cycles. The controller can manage loads up to 1440 VA.
Physical and Environmental
The unit measures 90 mm high (104 mm with the DIN latch open), 160 mm wide, and 87 mm deep. It weighs 2.4 pounds and operates between 0 and 55 degrees Celsius. Power supply inrush current reaches 25A for 8 ms at 120V AC and 40A for 4 ms at 240V AC.
Communication
Both ports use an 8-pin mini-DIN circular interface. The communication port supports DF1 full and half duplex, DH-485, ASCII, and MODBUS master/slave. With MODBUS, direct integration to power meters, smart relays, and switches happens without a converter or gateway.
Industry Applications
Water and Wastewater Treatment
Aging control panels often need a drop-in PLC that matches existing 120V AC field devices. The 1762-L40AWAR’s 24 AC inputs and 16 relay outputs map directly to pump starters, valve actuators, and level switches without signal converters.
Manufacturing and Production Lines
The ASCII protocol interfaces barcode scanners commonly used in production tracking. Combined with MODBUS support, the controller connects to smart relays and power meters on the same serial network.
Oil and Gas Skids
Remote wellhead panels benefit from the wide 120-240V AC power range and 0 to 55 degrees Celsius operating window. The compact 160 mm width fits tight enclosures where panel space is limited.
Installation and Setup
Mount the controller inside an enclosure that provides adequate protection for the installation area. Climate control devices may be needed to maintain the designed operating temperature. Wire inputs for sink or source configuration based on your field device type. The programming port handles configuration and user program downloads exclusively, while the communication port can serve both device communication and programming.
For serial networks, confirm cable and gateway requirements with your supplier before commissioning. The 8-pin mini-DIN interface works with an Allen-Bradley 1761-CBL-PM02 cable or a custom fabricated equivalent.
Integration and Compatibility
The 1762-L40AWAR supports limited expansion, so verify your I/O count before specifying additional modules. Its DF1 and DH-485 protocols follow the RS232 serial standard. MODBUS master/slave capability means the controller talks directly to MODBUS-capable devices without extra hardware.
When wiring into fieldbus networks, you may need an external gateway or connection module. Confirm cables and gateways with Oil AutoTech before ordering.
Selection Guide
Before purchasing, verify your input voltage matches the 120V AC input circuit type and confirm relay output loads stay within the 24-125 VDC or 120-240 VAC contact rating. Check that your panel depth accommodates the 87 mm unit depth. If you need a replacement or spare, Oil AutoTech provides fast-dispatch spares for oil, gas, and industrial automation applications with quick worldwide delivery. Contact Oil AutoTech today for pricing and availability.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
