Allen-Bradley 1756-L62 ControlLogix 5562 Controller (4MB Memory)

Description

Key Technical Specifications

Product Introduction & Supply Chain Strategy

This product is a Brand New Surplus unit. It is not used, not pulled from a decommissioned plant, and not refurbished. All modules undergo rigorous quality verification to ensure OEM-level reliability. The Allen-Bradley 1756-L62 is a mid-to-high capacity controller in the ControlLogix 5560 family, featuring 4 MB of integrated onboard memory. Unlike its predecessor (the 1756-L55), the 1756-L62 features built-in onboard RAM memory without requiring external RAM daughtercards, and utilizes convenient CompactFlash cards for non-volatile program backup.

With Rockwell Automation transitioning the 5560 family (L6x series) to active-discontinued status, upgrading to ControlLogix 5570 (L7x) or 5580 (L8x) controllers often forces expensive system overhauls—including software version migrations, firmware flashing, and re-qualification testing in validated environments. Sourcing a factory-fresh surplus 1756-L62 provides an immediate 1:1 drop-in replacement that eliminates engineering overhead, preserves your existing RSLogix 5000 project code, and keeps production lines operating reliably.

Installation & Configuration Guide

1.Stage 1: Pre-Installation (Prep & Safety):Perform software backup, isolate rack power, and attach ESD wrist strap.

• Upload and save a complete project backup (.ACD file) using RSLogix 5000 before removing the target controller.
• Enforce strict Lock-Out/Tag-Out (LOTO) protocols on the ControlLogix chassis power supply.
• Wear a grounded Electrostatic Discharge (ESD) wrist strap attached to an unpainted metal surface on the cabinet panel.
• Verify that a fresh 1756-BA2 battery (and optional 1756-M12/M13 CompactFlash card) is properly installed in the controller’s front-access slot.

2.Stage 2: Removal:Set keyswitch to PROG, disconnect serial cabling, and unlatch CPU.

• Turn the physical front-panel keyswitch to the PROG position.
• Disconnect any 1756-CP3 serial cable connected to the 9-pin D-shell RS-232 port.
• Depress the upper and lower module retention clips on the 1756-L62 housing.
• Slide the controller horizontally straight out of the chassis slot to protect the backplane pins.

3.Stage 3: Installation (Clone & Seat):Align guide rails, seat controller, and secure retainers.

• Align the top and bottom circuit board edges of the replacement 1756-L62 with the guide rails in the designated chassis slot.
• Push the controller firmly into the rack until both retention latches snap securely onto the chassis frame.
• Re-connect the RS-232 serial cable or verify communication through adjacent EtherNet/IP or ControlNet bridge cards.

4.Stage 4: Power-On & Testing:Power up chassis, check status LEDs, and download RSLogix 5000 project.

• Re-apply power to the ControlLogix chassis power supply.
• Observe the front LED indicators: verify RUN is OFF, FORCE is OFF, BAT is OFF (healthy battery), and OK turns solid GREEN after initial self-test.
• Open RSLogix 5000 (v12 through v20), connect to the processor, match the target firmware revision, and download your project file.
• Switch the keyswitch to REM or RUN and verify that all I/O modules and network adapters go online without connection faults.

1756-L62

1756-L62

Firmware/Software Versions & Upgrade Notes

• Software Compatibility: Programmed using RSLogix 5000 (supported from Version 12 up to Version 20). Note that ControlLogix 5560 controllers (L6x) cannot be programmed with Studio 5000 Logix Designer (v21+).
• Firmware Flashing: Firmware major/minor revisions (e.g., v16, v19, v20) can be flashed to the unit using ControlFLASH or ControlFLASH Plus over the front RS-232 port or across the backplane through a 1756-ENBT/EN2T module.
• Non-Volatile Memory (CompactFlash): The 1756-L62 supports 1756-M12 (64MB), 1756-M13 (128MB), and 1756-M15 (512MB) CompactFlash cards. You can configure the module in RSLogix 5000 to automatically load the project from CompactFlash upon power-up on corrupt memory, safeguarding operations against prolonged battery failure.

Frequently Asked Questions (FAQ)

What is the main difference between the 1756-L61, 1756-L62, and 1756-L63 controllers?

All three controllers belong to the ControlLogix 5560 family and share identical processing architecture. The key difference is user memory capacity:

• 1756-L61: 2 MB User Memory
• 1756-L62: 4 MB User Memory
• 1756-L63: 8 MB User Memory

Can I upgrade a 1756-L61 to a 1756-L62 without modifying my code logic?

Yes. Because the 1756-L62 belongs to the same 5560 hardware series, you can simply change the controller type in the RSLogix 5000 project properties from 1756-L61 to 1756-L62 and re-download. All code logic, I/O tags, and task structures remain completely identical.

Why is the BAT LED solid red on my 1756-L62 module?

A solid red BAT LED indicates that the onboard lithium battery (1756-BA2) voltage is low. If chassis power is turned off while the BAT LED is red, the active RAM memory will be wiped unless a non-volatile CompactFlash card is configured. Replace the battery while chassis power is ON to avoid program loss.

What does a solid red OK LED mean on the 1756-L62 front panel?

A solid red OK LED signifies a non-recoverable major fault (CPU hardware failure or severe memory corruption). Try cycling power or re-flashing the firmware via ControlFLASH. If the light remains solid red after power cycling, the processor hardware has suffered internal failure and must be replaced.

What warranty is included with this New Surplus controller?

We back this unit with a comprehensive 1-Year hardware replacement warranty (depending on your service agreement tier). If any hardware defect occurs during normal operation, an immediate replacement unit is dispatched directly from our buffer stock.