Description
The Allen-Bradley 1766-L32BXB is a 24 V DC-powered, DIN-rail or panel-mounted programmable logic controller (PLC) within the MicroLogix 1400 family. It features a built-in LCD interface, embedded digital and analog I/O channels, and multiple isolated communication ports supporting legacy and modern industrial protocols. This controller executes machine-level control logic utilizing the RSLogix 500 programming platform, serving as an standalone automation solution for manufacturing, water treatment, and infrastructure control systems.
Commercial and Availability Status
- Product Condition: New Original (Factory Sealed) or Refurbished (Fully Bench-Tested / Certified)
- Lifecycle Status: Discontinued / Obsolete by OEM (Active service parts, technical support, and replacement stock are handled through specialized industrial automation distribution channels).
- Warranty: 12-Month Industrial Warranty
- Estimated Lead Time: 1–3 business days (Global express priority shipping)
- Pricing Note: List pricing is indicative due to the obsolete status of the MicroLogix 1400 series. Contact our parts division for a formal, time-sensitive quotation based on current service stock availability.
Technical Specifications
Hardware and Power Configuration
| Parameter | Value |
| Model Number | 1766-L32BXB |
| Product Line | MicroLogix 1400 |
| Input Power Supply | 24 V DC (Acceptable range: 20.4 to 26.4 V DC) |
| User Memory Capacity | 20 KB total (Configurable for user program and data files) |
| Data Backup Profile | Non-volatile flash memory (Requires zero battery backup for long-term retention) |
| Dimensions | 90 mm (H) × 180 mm (W) × 87 mm (D) |
| Net Weight | 0.90 kg (2.00 lbs) |
Embedded I/O Channels
| Parameter | Value |
| Total Embedded I/O | 32 Digital channels, 4 Analog channels |
| Digital Inputs | 20 x 24 V DC Inputs (Includes 12 fast / high-speed 100 kHz inputs) |
| Digital Outputs | 6 x Relay Outputs (2 A maximum per channel, isolated outputs)
6 x 24 V DC FET Transistor Outputs (Includes 3 high-speed 100 kHz PTO/PWM outputs) |
| Analog Inputs | 4 x Single-ended channels voltage-only (0 to 10 V DC, 10-bit resolution) |
| Analog Outputs | 2 x Single-ended channels voltage-only (0 to 10 V DC, 12-bit resolution) |
| Expansion Capability | Supports up to 7 x 1762 MicroLogix expansion I/O modules |
Integrated Communication Interfaces
| Port Profile | Physical Layer | Supported Protocols |
| Port 1 (Isolated) | RJ45 Ethernet (10/100 Mbps) | EtherNet/IP, Modbus TCP/IP, DNP3 over IP |
| Port 0 (Non-Isolated) | 8-pin Mini-DIN RS-232C / RS-485 | DF1 Full/Half Duplex, Modbus RTU Master/Slave, DH-485, ASCII |
| Port 2 (Isolated) | 9-pin D-shell (DB9) RS-232C | DF1 Full/Half Duplex, Modbus RTU, DH-485, ASCII, Radio Modem |
Technical Application and Field Integration Constraints
Hybrid Output Considerations
The 1766-L32BXB utilizes a split output structure combining mechanical relays and solid-state FET transistors.
- Relay Channels (Outputs 0–5): Provide full dry-contact electrical isolation. These are ideal for running external 120/240 V AC interlock contactors or pilot lights up to a maximum inductive limit of 2 A.
- FET Channels (Outputs 6–11): Sourced strictly by 24 V DC. The first three channels (Outputs 6, 7, and 8) route directly through the controller’s internal high-speed Pulse Train Output (PTO) or Pulse Width Modulation (PWM) hardware clocks. Use these paths exclusively for close-coupled servo drive step/direction commands or localized speed regulation.
Grounding and Non-Isolated Interface Safety
Port 0 utilizes a standard 8-pin Mini-DIN socket that shares its ground path directly with the controller’s internal logic reference.
Field Engineering Warning: If Port 0 is connected to a long-distance RS-485 network across multiple control cabinets without an external optical isolator (such as a 1761-NET-AIC module), any common-mode voltage difference between the panels will route back through the controller’s main board. This will cause communication failures or destroy Port 0’s internal serial transceiver IC.
Frequently Asked Questions
Which software packages program the 1766-L32BXB?
Programming and online diagnostics require RSLogix 500 (Standard, Professional, or Starter editions, Version 8.10 or higher). Note that the free RSLogix 500 Micro Starter software does not support the MicroLogix 1400 line; it is restricted to the MicroLogix 1100 series. The system is configured through standard RSLinx Classic utility profiles.
How do I configure the embedded analog inputs to read 4 to 20 mA signals?
The onboard analog blocks are physically restricted to a 0 to 10 V DC voltage spectrum. To capture standard 4 to 20 mA field instrumentation signals, you must place a high-precision 500\ \Omega (0.1\% tolerance, 0.25\ W) resistor across the target channel’s positive and negative input terminals. This drops the incoming current signal into a usable 2 to 10 V DC window, which can then be scaled within the RSLogix SCP (Scale with Parameters) instruction block.
Can this controller operate directly as a Modbus TCP Master or Slave?
Yes. The integrated RJ45 Ethernet interface supports native Modbus TCP/IP protocol mappings natively alongside standard EtherNet/IP. These settings are toggled under the Channel Configuration tree inside the project file, enabling the module to read or write data to third-party VFDs, power meters, or HMI
