Allen‑Bradley 1762‑L40BXB MicroLogix 1200 Controller

1762‑L40BXB 24V DC PLC – Allen‑Bradley MicroLogix 1200

Product Introduction

The 1762‑L40BXB programmable controller belongs to the Allen‑Bradley MicroLogix 1200 series. This model is designed for small to medium control systems that require a balanced mix of discrete I/O points. It operates on a 24V DC supply and delivers 24 total inputs along with 16 outputs. Its built‑in RS232 port supports several communication protocols, giving you flexible connectivity for programming and monitoring.

Technical Specifications

This controller offers 24 inputs, consisting of 20 standard 24V DC inputs and 4 fast 24V DC inputs. The fast inputs handle frequencies up to 20 kHz, ideal for high‑speed counting or pulse capture. The outputs are arranged as 8 relay outputs, 7 FET outputs at 24V DC, and 1 high‑speed FET output.

The input circuit is configurable as sink or source, which simplifies wiring with various sensors. For inputs 0 to 3, the on‑state voltage is 14‑24V DC, and the off‑state range is 0‑5V DC. For inputs 4 and above, the on‑state voltage spans 10‑24V DC, with a nominal impedance of 2.7 kΩ. The off‑state leakage current is 1.5 mA for all inputs.

Furthermore, the integrated power supply draws 100‑240V AC at 47‑63 Hz and provides 600 mA at 5V DC and 500 mA at 24V DC. The module dissipates 21 watts of heat and has a power supply usage of 82 VA. Inrush current peaks at 25A for 8 ms on 120V AC and 40A for 4 ms on 240V AC.

Mechanical and Environmental Parameters

Physically, the 1762‑L40BXB measures 90 mm in height, 160 mm in width, and 87 mm in depth. With the DIN latch open, the height increases to 104 mm. It operates reliably in ambient temperatures from 0 to 55 °C. The relay contacts are rated for 24‑125V DC and 120‑240V AC, with a minimum load current of 10A. Mechanical endurance reaches 20 million cycles, ensuring long‑term durability.

Communication and Expansion Options

An 8‑pin mini DIN RS232 port supports ASCII, DH485, MODBUS, and DF1 protocols. You can use this port to upload and download programs, as well as to monitor and commission the system.

Additionally, the controller includes a trimmer potentiometer for data adjustment or analog simulation, which you can modify with a small flathead screwdriver. The built‑in memory module can be replaced with the 1762‑MM1 for extended storage, or with the 1762‑RTC if real‑time clock functionality is needed. For combined memory and RTC, choose the 1762‑MM1RTC. A real‑time clock is essential when time‑stamping events or running scheduled processes.

Installation Guidelines

Mount the 1762‑L40BXB on a standard DIN rail or use panel mounting. Ensure the enclosure provides adequate airflow and maintains the ambient temperature within 0‑55 °C. Connect the 24V DC power supply to the dedicated terminals, observing correct polarity. Use shielded cables for the fast input channels to minimise electrical noise. The current per group must not exceed 8A; exceeding this limit may damage the module. Always ground the controller properly to protect against electrostatic discharge.

Packaging List

• 1762‑L40BXB MicroLogix 1200 controller

• Terminal block connectors (removable)

• DIN rail mounting clips

• Product quick‑start guide

• Shipping package with anti‑static protection

Shipping method: FedEx, UPS, or DHL.

Frequently Asked Questions

1. Can I use the 1762‑L40BXB with a 24V AC power source?
No. This controller requires a 24V DC power supply with a tolerance of -15% to +10%. Using AC power will damage the unit.

2. How do I connect a programming terminal to this PLC?
Use the 8‑pin mini DIN RS232 port with a suitable cable. The port supports DF1, DH485, MODBUS, and ASCII protocols for easy connection.

3. What is the difference between the standard and fast inputs?
The fast inputs (0‑3) handle frequencies up to 20 kHz, while standard inputs (4 and above) operate up to 1 kHz. This makes the fast inputs suitable for high‑speed counting or encoder signals.

4. Can I expand the memory of the 1762‑L40BXB?
Yes. You can replace the built‑in memory with the 1762‑MM1 module. For real‑time clock functions, use the 1762‑RTC or the combined 1762‑MM1RTC.

5. What is the maximum current per input group?
The maximum current per group is 8A. Exceeding this limit may cause permanent damage to the controller. Always check your load distribution before wiring.