Product Overview
The Allen-Bradley 1764-LSP is the base processor unit of the MicroLogix 1500 brick-style controller. It mounts on a 1764 power-supply/base I/O module to form a compact PLC for small machine and process control. If your line runs on the Bulletin 1764 platform, this processor is the control core that keeps it moving.
Please note: the 1764-LSP was discontinued on June 30, 2017. Rockwell Automation lists a functional replacement path toward MicroLogix 1400 or CompactLogix 5370. For plants still running MicroLogix 1500 hardware, ready-to-ship spares remain the practical way to avoid unplanned downtime. Contact Oil AutoTech today for pricing and availability.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 1764-LSP |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Series | MicroLogix 1500 / Bulletin 1764 |
| Product Type | Processor / Controller (Base Unit) |
| User Memory | 7.6K word (Series B 12K / Series C 14K) |
| Communication Port | RS232 (DH-485, DF1, Modbus, ASCII) |
| Expansion I/O | Up to 512 points |
| Compatible Base Units | 1764-AWA, 1764-BWA, 1764-BXB |
| Memory Modules | 1764-MMx, 1764-RTC |
| Backup | RAM + 1764-BATM battery |
| Bus Current | ~380 mA |
| Trim Pots | 2 built-in |
| Mounting | DIN rail / panel |
| Lifecycle Status | Discontinued (2017-06-30) |
What the Key Specs Mean in Practice
The 7.6K word user memory handles small to mid-size ladder programs — enough for interlocking, timers, counters and basic process logic. Series B and C revisions expand that to 12K and 14K word, so verify your exact revision before matching a spare.
The RS232 port supports DH-485, DF1, Modbus and ASCII. That flexibility lets the processor talk to HMIs, drives and older supervisory systems without extra hardware in many cases.
With support for up to 512 expansion I/O points, the 1764-LSP scales beyond its embedded I/O. The ~380 mA bus current draw matters when sizing the base power supply.
Applications and Integration
Typical deployments include small machine control, packaging lines, water treatment skids and process monitoring. In oil and gas, these controllers often sit on auxiliary skids and remote panels where compact logic control is required.
Integration Note: wiring into DH-485 or Modbus networks may require an external gateway or connection module. Confirm cables and gateways with your supplier before commissioning.
The processor is programmed with RSLogix 500 / RSLogix Micro and shares its instruction set with the SLC 500 family, which shortens migration effort for existing users.
Replacement and Maintenance Guidance
Because the platform is discontinued, treat every installed 1764-LSP as a critical spare. Keep at least one verified unit on the shelf. The 1764-BATM lithium battery backs volatile CMOS RAM; inspect it periodically and follow the manufacturer’s manual for replacement intervals.
For long-term planning, budget a phased migration to MicroLogix 1400 or CompactLogix 5370. Until then, fast dispatch, worldwide sourcing keeps legacy lines running.
Selection Checklist
Before ordering, confirm your base unit model (1764-AWA, 1764-BWA or 1764-BXB), your required memory revision, and whether a 1764-MMx memory module or 1764-RTC is fitted. Oil AutoTech offers hands-on technical selection help to match the right unit to your panel.
