OVERVIEW

Official designation: Allen-Bradley 1753-L28BBBM (GuardPLC 1600 Series, Safety Controller)

Role/Application: A compact safety controller for robust industrial automation and functional safety applications, featuring integrated digital inputs and outputs for local control.

KEY SPECS SUMMARY

Power: 24V DC nominal, 8 Amps max current

Interfaces / Ports: 4 Ethernet, 2 RS-485, 1 Comm port

Indicators: Status, diagnostic, and I/O LEDs

Operating Temp: Refer to the latest manufacturer manual.

Platform / Compatibility: GuardPLC 1600 System, RSLogix Guard PLUS!

Limit: 20 Safety Inputs, 8 Safety Outputs

Lifecycle: Current Product (varies by series/revision)

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What are the total available user memory resources in the 1753-L28BBBM safety controller?

A: The controller provides 250 KB for program memory and an additional 250 KB for application data memory.

Wiring & Installation:

Q: What are the minimum clearance requirements for proper cooling when mounting the controller?

A: A minimum gap of 100 millimeters (3.94 inches) must be provided above and below the controller.

Troubleshooting & Compatibility:

Q: What specific communication protocols are supported on the 9-pin D-shell RS-485 ports?

A: The RS-485 ports support Modbus RTU Slave and GuardPLC ASCII protocol for communication.

Replacement & Upgrades:

Q: Does the 1753-L28BBBM model support connecting to standard PLCs or HMI devices?

A: Yes, it supports communication to standard PLCs and HMI devices using Modbus RTU Slave or PROFIBUS DP Slave options.