Overview
The Allen-Bradley 1785-L30B is a PLC-5/30 processor module designed for mid-sized industrial automation and control applications. This Series C processor delivers reliable performance in manufacturing, process control, and discrete automation environments where DH+ networking and Remote I/O architecture are required. The 1785-L30B supports extensive I/O configurations and integrates seamlessly with existing PLC-5 systems.
Key Features
- 32K words of user program memory with battery-backed RAM
- Two integrated DH+/Remote I/O communication ports plus one configurable serial port (RS-232/422A/423)
- Supports up to 1024 total I/O (mixed discrete and analog) or complementary 1024 input + 1024 output configuration
- Capable of controlling up to 28 Remote I/O racks for distributed control architectures
- Three-position key switch (Run/PROG/REM) and LED status indicators for battery, controller state, and I/O force status
- Backplane-powered operation from standard 1771 chassis (5-slot or larger)
Technical Specifications
- Memory: 32K words user program storage
- Communication Protocols: DH+ (Data Highway Plus), Remote I/O, Serial DF1 (via adapter)
- Communication Ports: 2× DH+/Remote I/O, 1× RS-232/422A/423 configurable
- Maximum I/O: 1024 total (any mix) or 1024 input + 1024 output
- Remote I/O Racks Supported: Up to 28
- Power Supply: 5V DC from backplane (1.75A typical)
- Operating Temperature: 0°C to +60°C
- Battery Backup: Yes, maintains memory 84 days at full charge / 150 days at 50% charge
- Chassis Compatibility: Allen-Bradley 1771 5-slot or larger chassis
- Programming Software: RSLogix 5
- Instruction Set: Bit, timer, counter, math, PID, block transfer, data move
- Certifications: UL, CSA listed
Typical Applications
- Discrete manufacturing and assembly line automation
- Process control with DH+ networked I/O
- Remote I/O-distributed control architectures
- Legacy system upgrades and expansion (PLC-5 family)
- Machine tool control and motion applications
- SCADA-integrated control systems
Compatibility & Replacements
Compatible With
- Allen-Bradley 1771 series I/O modules and chassis (5-slot or larger)
- DH+ (Data Highway Plus) networks and remote I/O scanners
- RSLogix 5 programming software
- Allen-Bradley communication modules (Ethernet gateways, serial adapters)
- PLC-5 family control systems and networks
Replaces / Drop-In Replacement For
- Allen-Bradley 1785-L30B Series A, B, and earlier revisions
- Legacy PLC-5/30 processor modules in original 1771-based systems
Works With
- RSLogix 5 (Rockwell Automation programming environment)
- DH+ communication networks
- Remote I/O architecture (RIO Scanner modules)
- RS-232, RS-422A, RS-423 serial protocols
- DF1 serial protocol (with adapter)
