Allen-Bradley 1747-L551 – SLC 5/05 Processor Module

The Allen-Bradley 1747-L551 is an SLC 5/05 processor module. Specifically, this module belongs to the SLC 500 series from Rockwell Automation. It is a high-performance controller with integrated Ethernet communication. Furthermore, it supports both online and offline programming including runtime editing. In addition, this processor offers channel-to-channel pass-thru capabilities. Consequently, this processor suits demanding control applications requiring network connectivity.

Ordering Configuration and Product Identification

• Manufacturer: Rockwell Automation.

• Brand: Allen-Bradley.

• Part Number: 1747-L551.

• Series: SLC 500.

• Module Type: SLC 5/05 Processor.

• Chassis Location: Slot 0 only (exclusive).

• Backup Memory Module: 1747-M13 (up to 64KB).

• Battery Backup: 1747-BA supported.

• UPC: 10662072745622.

• UNSPSC: 32151705.

• Therefore, the Allen-Bradley 1747-L551 installs exclusively in the first chassis slot.

Memory Specifications

• User Memory: 16,000 words (16 KB).

• Memory Type: Battery-backed CMOS RAM.

• Backup Memory Capacity: Up to 64KB with 1747-M13 module.

• Battery Backup Support: Yes, using 1747-BA battery.

• Program Scan Time: 0.9 milliseconds per K-word.

• I/O Scan Time: 0.225 milliseconds typical.

• Programming Support: Online and offline programming.

• Runtime Editing: Yes, fully supported.

• Indirect Addressing: Supported for flexible programming.

• Advanced Math Instructions: Included for complex calculations.

• Thus, the 1747-L551 provides fast program execution for complex control logic.

I/O Capacity and Chassis Configuration

• Discrete Inputs: 4096 maximum.

• Discrete Outputs: 4096 maximum.

• Analog I/O: 480 maximum.

• I/O Chassis Supported: 3 total.

• Chassis Module Slots: 30 slots total across 3 chassis.

• Remote I/O Support: Yes, with communication adapter.

• Distributed I/O: Supported via remote chassis.

• Local Chassis: Processor treats remote modules as local.

• I/O Scanning: Handles both local and remote I/O seamlessly.

• Consequently, the Allen-Bradley 1747-L551 scales to large I/O configurations.

Communication Ports and Protocols

• Integrated Ethernet Port: 10/100 Base-T channel.

• Ethernet Protocols: SNMP, BOOTP, extended messaging.

• Ethernet Function: High-speed communication and networking.

• RS-232 Port: For peer-to-peer communication.

• RS-232 Protocols: DF1 full duplex, DF1 half-duplex master, DF1 radio modem.

• Channel-to-Channel Pass-thru: Supported for flexible routing.

• Remote I/O (RIO) Pass-thru: Supported for remote access.

• DeviceNet Pass-thru: Supported for device networks.

• DH485 Protocol: Supported for legacy networks.

• Data Highway Plus (DH+): Supported for high-speed peer networks.

• Note: RIO (Remote I/O) is a proprietary Allen-Bradley protocol.

• Remote I/O Technology: Allows I/O modules away from processor.

• Distributed Processing: Remote chassis operate independently.

• Therefore, the 1747-L551 offers versatile connectivity for industrial networks.

Real-Time Clock and Calendar

• Built-in Real-Time Clock: Yes, integrated.

• Built-in Calendar: Yes, included.

• Function: Time-stamping and scheduled events.

• Battery Backup: Maintains clock during power loss.

• Application: Data logging and time-based control.

• Accuracy: Standard industrial RTC precision.

• Scheduling: Enables time-of-day program execution.

• Thus, the Allen-Bradley 1747-L551 supports time-sensitive applications without external hardware.

LED Status Indicators

• RUN LED: Indicates processor is running.

• CPU Fault LED: Indicates processor fault condition.

• Battery Low LED: Warns when battery needs replacement.

• Force LED: Indicates I/O forces are active.

• Ethernet Active LED: Shows Ethernet port activity.

• RS-232 Active LED: Shows serial port activity.

• Troubleshooting: Visual diagnostics without additional tools.

• Power-Up: LEDs confirm proper operation.

• Fault Identification: Quick diagnosis of common issues.

• Consequently, operators can quickly identify processor status.

Temperature and Environmental Ratings

• Operating Temperature: 0°C to 60°C (32°F to 140°F).

• Storage Temperature: -40°C to 85°C (-40°F to 185°F).

• Relative Humidity: 5% to 95% non-condensing.

• Operating Shock: 30G (3 pulses, 11 milliseconds).

• Non-operating Shock: 50G (3 pulses, 11 milliseconds).

• Operating Vibration: 2.5G at 5 to 2000 Hz.

• Non-operating Vibration: 5G at 5 to 2000 Hz.

• Dielectric Withstand (UL 508/CSA C22.2): 150 Volts AC.

• Isolation (Communication Circuits): 500 Volts DC.

• Isolation (Backplane to I/O): 1500 Volts AC.

• Chemical Resistance: Avoid direct chemical exposure.

• Therefore, the Allen-Bradley 1747-L551 withstands typical industrial conditions.

HMI and SCADA Compatibility

• HMI Integration: Supported via Ethernet or RS-232.

• SCADA Integration: Supported via Ethernet or RS-232.

• DF1 Protocol: Common for HMI connections.

• Ethernet Messaging: Extended capabilities for data exchange.

• Computer-Based Control Systems: Fully compatible.

• Data Access: Read/write to processor memory tables.

• Remote Monitoring: Supported across network connections.

• Alarm Handling: Enables remote alert management.

• Data Logging: Supports historical data collection.

• Thus, the 1747-L551 integrates seamlessly with visualization and supervisory systems.

Installation Guide

First, verify that all system power sources are completely disconnected. Then, locate slot 0 in your SLC 500 chassis. The Allen-Bradley 1747-L551 must be installed in this specific slot only. After that, slide the processor module into slot 0. Push firmly until the backplane connector is fully seated. Next, install the 1747-BA battery for memory backup. For expanded backup memory, insert the 1747-M13 memory module. Then, connect your Ethernet network to the 10/100 Base-T port. Subsequently, connect your RS-232 device to the serial port if needed. After that, apply power to the SLC 500 chassis. The processor will begin its power-up sequence. Observe the RUN LED to confirm normal operation. Then, download your control program using appropriate programming software. Configure the Ethernet port for your network (SNMP, BOOTP, or fixed IP). Set up DF1 parameters for RS-232 communication if used. Finally, test all I/O connections and communication paths. As a result, the Allen-Bradley 1747-L551 will provide reliable control and network connectivity.

Packaging List

• One Allen-Bradley 1747-L551 SLC 5/05 processor module

• One 1747-BA battery (installed or included)

• One product identification label

• One installation and configuration guide

• One communication port pinout sheet

Common FAQs

Q1: How much user memory does the Allen-Bradley 1747-L551 provide?
A: This processor provides 16,000 words (16 KB) of user memory. Specifically, it uses battery-backed CMOS RAM. Additionally, the 1747-M13 memory module provides up to 64KB of backup memory.

Q2: What communication ports are on the 1747-L551?
A: This processor has an integrated Ethernet port (10/100 Base-T). It also has an RS-232 port for peer-to-peer communication. Therefore, it supports Ethernet, DF1, DH485, and Data Highway Plus protocols.

Q3: What is the program scan time for the Allen-Bradley 1747-L551?
A: The typical program scan time is 0.9 milliseconds per K-word. Furthermore, the I/O scan time is 0.225 milliseconds. Consequently, it suits high-speed control applications.

Q4: Can the 1747-L551 support remote I/O chassis?
A: Yes, remote I/O implementation is supported. A communication adapter installs in the chassis with the CPU. Additionally, scanner modules install in remote chassis with I/O modules.

Q5: What do the LED indicators show on the Allen-Bradley 1747-L551?
A: The RUN LED shows processor operation status. The CPU FAULT LED indicates a processor fault. The BATTERY LOW LED warns of low battery. Furthermore, the FORCE LED shows active I/O forces. Finally, Ethernet and RS-232 LEDs show port activity.