Allen-Bradley 1761-L16BWA Programmable Logic Controller

The 1761-L16BWA is a compact programmable logic controller in the Allen-Bradley MicroLogix 1000 series engineered for standalone machine control. Operating on an line AC supply of 85–264 VAC, this unit combines 10 discrete 24 VDC inputs with 6 electromagnetic relay outputs in a single integrated housing. It provides a compact footprint and reliable ladder logic processing for small-scale industrial automation applications.

Integrated I/O and Power System

The controller includes 10 embedded 24 VDC digital inputs that accept both sinking and sourcing wiring configurations, including high-speed counter functionality on select channels. Output switching is handled by 6 relay channels capable of driving both AC and DC loads across isolated circuit groups. Powered by an line AC supply (120/240 VAC nominal, 47–63 Hz), the controller also provides an auxiliary 24 VDC output (up to 200 mA) to power external sensors directly from the controller terminals.

Memory Architecture and Retention

Program instructions and data registers reside in 1 K EEPROM non-volatile memory. This architecture retains approximately 737 instruction words and 437 data words permanently without relying on a battery backup. Retentive data and bit registers remain fully intact across long-term power outages, ensuring reliable operational recovery upon restoration.

Serial Interface and Network Integration

An integrated RS-232 mini-DIN port supports the Allen-Bradley DF1 protocol for direct, point-to-point communication. Using standard programming cables (such as 1761-CBL-PM02), the controller connects to PC software, operator terminals, or hand-held programmers. For multi-drop industrial communication, the serial port can be linked to a DH-485 network using an external 1761-NET-AIC Advanced Interface Converter.

Technical Parameters

Frequently Asked Questions

Q: What power supply voltage is required to operate the 1761-L16BWA controller? A: The controller features an internal AC power supply rated for an operating input range of 85 to 264 VAC at 47 to 63 Hz.

Q: Does the 1761-L16BWA require a lithium battery to preserve the ladder program? A: No, the unit utilizes onboard non-volatile EEPROM memory to retain user logic and configuration data indefinitely without battery power.

Q: Can the 1761-L16BWA provide power directly to field sensors? A: Yes, the built-in AC power supply includes an auxiliary 24 VDC output capable of supplying up to 200 mA to field sensors and input switches.