The Allen-Bradley 1785-L11B standard processor acts as the central controller for your automation system.
It integrates both local and remote I/O modules into one unified control environment.
This processor efficiently connects devices across various communication interfaces for superior process management.
The 1785-L11B processor supports up to 512 total I/O points in any combination.
This allows for 512 analog I/O or a mix of discrete signals for flexible system design.
With 8 Kilowords of user memory, it handles complex logic for mid-sized applications.
Theme A: Product Procurement and Buyer Guide
Procurement teams require a processor that offers reliability and proven technology for legacy systems.
The 1785-L11B delivers this with its robust PLC-5 architecture and standard processor designation.
It features battery-backed static RAM to protect your program during power outages.
This processor also accepts EEPROM backup modules like the 1785-ME16 for secure program storage.
The unit dissipates only 12 Watts of power during normal operation.
This low heat output reduces thermal stress inside the control cabinet.
The backplane current load is just 2.3 Amps at 5 Volts.
This ensures compatibility with standard power supplies in your chassis.
For project planning, the 1785-L11B scans a single rack in only 10 ms at 57.6 kbits/s.
This speed increases to just 3 ms at 230.4 kbits/s for faster data throughput.
Engineers can configure the single RS-232-C port for ASCII or DF1 protocols.
This provides flexible connectivity for programming terminals or older equipment.
The processor also includes a control coprocessor expansion port for added functionality.
This makes the 1785-L11B a smart choice for extending the life of existing PLC-5 installations.
Theme B: Step-by-Step User and Installation Guide
Deploying the 1785-L11B requires careful attention to the chassis and communication setup.
Start by inserting the processor into the left-most slot of a 1771 series chassis.
Ensure the backplane connectors align correctly to avoid pin damage.
The processor works with a maximum of five I/O chassis in a complete system.
You can use up to four of those chassis as universal remote I/O units.
Next, connect your programming terminal to Channel 1A using an 8-pin mini DIN cable.
This channel supports Data Highway Plus (DH+) for remote programming and monitoring.
Configure all DH+ devices to run at the same transmission rate for stable communication.
Use a maximum cable length of 3048 meters at 57.6 kbits/s for long-distance links.
For higher speed, reduce the cable length to 762 meters at 230.4 kbits/s.
Use the front panel key-switch to select the correct operating mode for your task.
Select RUN mode to enable outputs and execute your control program.
Select PROG mode to disable outputs and create or modify ladder logic files.
Select REM mode to allow remote control over run, program, or test states.
The COMM indicator lights green when Channel 0 is actively communicating.
Monitor the PROC indicator for a red fault signal during startup troubleshooting.
Logistics & Standard Packaging Details
Express delivery shipping is available via FedEx, UPS, and DHL for fast deployment.
