Introduction
For decades, the factory floor relied on compact, rugged controllers that could run a production line without a server rack or a climate-controlled cabinet. The Allen-Bradley MicroLogix 1500 answered that call, and the 1764-24BWA became a familiar sight in panels across oil fields, water treatment plants, and packaging lines. Rockwell Automation has since retired the platform, but thousands of these base units still run critical processes every day. When one fails, downtime is not an option. This guide explains exactly what the 1764-24BWA offers, where it fits, and how to plan a practical replacement path.
What Is the 1764-24BWA?
The 1764-24BWA is a processor and controller base unit from the Allen-Bradley MicroLogix 1500 series, also known as Bulletin 1764. It combines the CPU and embedded I/O in one compact package that mounts on a standard DIN rail or panel. The unit ships with 12 sinking or sourcing-configurable 24V DC inputs and 12 relay Form A outputs. Power comes from a 120/240V AC supply, which suits many legacy panels that never had a 24V DC bus. If you need to add 1769 Compact I/O as right-side expansion, the 1764-ECR end cap resistor is required. That single accessory detail matters because missing it stops the expansion bus from working.
Technical Specifications at a Glance
The table below lists the key parameters for this exact model. Every value comes from the manufacturer’s data for the 1764-24BWA.
| Specification | Value |
|---|---|
| Part Number | 1764-24BWA |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Series | MicroLogix 1500 / Bulletin 1764 |
| Product Type | Processor / Controller (Base Unit) |
| Inputs | 12 x 24V DC, sinking/sourcing configurable |
| Outputs | 12 x relay (Form A) |
| Power Supply | 120/240V AC |
| Expansion Requirement | 1764-ECR end cap resistor for 1769 Compact I/O |
| Lifecycle Status | Discontinued (2017-05-04) |
| Replacement Options | MicroLogix 1400 (1766-L32xxxx) or CompactLogix L1/L2 |
Inputs and Outputs
The 12 DC inputs accept 24V signals and let you configure each point as sinking or sourcing. That flexibility simplifies wiring when different field devices share one panel. The 12 relay outputs are Form A dry contacts, so they can switch AC or DC loads directly without an external interposing relay in many cases. For a discontinued unit, this I/O count still covers small conveyors, pump controls, and valve banks.
Power and Mounting
The 120/240V AC power input removes the need for a separate DC supply in older cabinets. The compact housing mounts on standard DIN rail and panel, which keeps retrofit work straightforward. Because the platform is end-of-life, verify the physical dimensions against your existing panel before you commit to a drop-in replacement.
Where the 1764-24BWA Still Fits
Oil and gas operations often keep legacy MicroLogix panels running because the process works and the upgrade budget is tight. A 1764-24BWA might control a tank farm valve sequence, a small pump station, or a water treatment dosing skid. In packaging, the same base unit handles simple start-stop logic and safety interlocks for a conveyor section. When a board fails, the fastest path back to production is a like-for-like spare, not a full controls redesign. That is where fast-dispatch spares for oil, gas and industrial automation make the difference between a short stop and a long outage.
Installation and Setup Notes
Mount the base unit on a standard DIN rail or panel and follow the manufacturer’s wiring diagrams for the 120/240V AC supply. Keep AC power wiring separated from low-level DC input wiring to reduce electrical noise. If you plan to attach 1769 Compact I/O, install the 1764-ECR end cap resistor on the right side as required by the system design. Program the unit with RSLogix 500 or RSLogix Micro software, which shares the SLC 500 instruction set. Always confirm terminal torque and grounding practices against the official installation instructions before energizing the panel.
Maintenance and Reliability
These controllers have no moving parts, so reliability depends mostly on the panel environment. Inspect the unit periodically for dust buildup, loose terminals, and signs of heat stress. Relay outputs are the main wear point because they carry mechanical contacts; if a relay drives a high-cycle load, consider an external interposing relay to extend contact life. Keep the cabinet within its rated ambient conditions and check that ventilation paths stay clear. For a discontinued platform, maintaining a known-good spare on the shelf is the most practical reliability measure you can take.
Compatibility and Integration
The 1764-24BWA communicates through serial interfaces common to the MicroLogix family, including RS-232, RS-485, and DH-485. It programs with RSLogix 500 and RSLogix Micro, and it shares the SLC 500 instruction set, so existing ladder logic often transfers with minimal edits. When you connect this controller to a plant network, you may need an external gateway or connection module. Confirm the correct cables and gateway for your architecture with your supplier before you order.
Replacement and Upgrade Path
Rockwell discontinued the MicroLogix 1500 platform, with this model’s official discontinuation date of 2017-05-04. The recommended replacements are the MicroLogix 1400 (1766-L32xxxx) or CompactLogix L1/L2 controllers. The MicroLogix 1400 keeps a similar compact form factor and adds embedded Ethernet on later models, which can simplify plant connectivity. CompactLogix L1/L2 moves you to a modern platform with better long-term support. Either path requires a review of your I/O count, power arrangement, and panel space. If you need hands-on technical selection help, the team at Oil AutoTech can match your existing wiring and program needs to the right replacement.
Frequently Asked Questions
Is the 1764-24BWA still in production?
No. Rockwell Automation lists the MicroLogix 1500 platform as end-of-life, and this model was discontinued on 2017-05-04. Availability now depends on remaining stock and the secondary market.
What replaces the 1764-24BWA?
The manufacturer points to the MicroLogix 1400 (1766-L32xxxx) or CompactLogix L1/L2 controllers as replacement options. The best choice depends on your I/O count and network requirements.
How many I/O points does this base unit have?
It provides 12 sinking or sourcing-configurable 24V DC inputs and 12 relay Form A outputs, all embedded in the base unit.
What do I need for 1769 Compact I/O expansion?
You must install the 1764-ECR end cap resistor to attach 1769 Compact I/O as right-side expansion. Without it, the expansion bus will not function correctly.
Can I still get a 1764-24BWA today?
Availability varies. Contact Oil AutoTech today for pricing and availability, and ask about ready-to-ship options for your panel.
Sourcing the 1764-24BWA
Legacy controllers keep plants running long after the catalog closes. When you need a 1764-24BWA, work with a supplier who understands oil, gas, and industrial automation panels and can confirm the exact configuration before shipping. Oil AutoTech offers fast dispatch, worldwide, with practical technical support to help you choose between a direct spare and a planned upgrade. Contact Oil AutoTech today for pricing and availability.
