Product Overview

The 1785-L46B is a PLC-5 programmable controller from Allen-Bradley. This device uses protected memory to secure critical data and programs. It offers 48,000 words of user memory and handles up to 2048 total I/O points. The controller supports complementary I/O configurations, allowing 2048 inputs plus 2048 outputs. It includes four ports for Data Highway Plus (DH+) or Remote I/O (RIO) networks. A serial port supports RS-232, RS-422, and RS-423 standards. These features make it a versatile choice for complex automation tasks.

Application Scenarios

This controller fits well in manufacturing plants and process industries. Use it for assembly lines, packaging systems, or material handling. It works with 1771 I/O chassis and various remote racks. The DH+ network connects multiple controllers and HMIs. The RIO scanner mode communicates with remote I/O modules. Typical applications include batch control, conveyor systems, and machine control. It also supports intelligent modules like analog and motion control.

Technical Specifications

• User memory: 48 kilowords (protected)
• Max total I/O: 2048 any mix or 2048 in + 2048 out (complementary)
• Communication ports: 4 configurable DH+/RIO, 1 serial (RS-232/422/423)
• Battery-backed static RAM preserves program during power loss
• Program scan time: 0.5 ms per K word for bit logic
• I/O scan time: 10 ms at 57.6 kbps, 7 ms at 115.2 kbps, 3 ms at 230.4 kbps
• Max I/O chassis: 61 total (60 remote + 1 local)
• Max analog I/O: 2048
• Backplane current: 3.0 A at 5V DC
• Power dissipation: 17.3 Watts (59.04 BTU/hr)
• Weight: 1.42 kg (3.1 lbs)
• Operating temperature: 0 to 60°C (32 to 140°F)
• Storage temperature: -40 to 85°C (-40 to 185°F)
• Humidity: 5 to 95% non-condensing
• Shock: 30G; Vibration: 1G at 10-500 Hz
• Certifications: UL, CSA, C-TICK, CE

Installation & Maintenance Guide

Install the 1785-L46B in the left-most slot of a 1771 chassis. Use only compatible chassis models like 1771-A1B, -A2B, -A3B, or -A4B. Ensure the backplane connects correctly via pins 40/42 and 54/56 for keying. Set the I/O addressing mode (2-slot, 1-slot, or 1/2-slot) before powering on. Connect DH+ or RIO cables to the four front ports. Use the serial port for programming or DF1 protocol. When replacing the battery (1770-XYC), follow safety procedures to avoid memory loss. Store the module in an open enclosure with proper ventilation. For firmware updates, use a 1785-ME memory module.

Packing List

Each shipment includes one 1785-L46B PLC-5 controller unit. No additional accessories are included. The product ships in anti-static packaging. Delivery uses trusted carriers such as FedEx, UPS, or DHL. Ensure proper handling to avoid damage during transit. Always verify the part number and condition upon receipt.