OVERVIEW

Official designation: Allen-Bradley 1746-BAS (SLC 500, BASIC Module)

The 1746-BAS SLC BASIC module extends SLC 500 capabilities by executing user-written BASIC programs, handling complex calculations, and managing serial communication via RS-232, RS-422, RS-485, and DH-485 ports.

KEY SPECS SUMMARY

Power: 5V DC, 750 mA (backplane)

Interfaces / Ports: One 9-pin RS-232, one 3-pin RS-422/485

Indicators: RUN, COM A, COM B, FAULT

Operating Temp: 0 to 60 degrees C

Platform / Compatibility: SLC 500 modular hardware

Limit: 24KB battery-backed RAM

Lifecycle: Discontinued

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the maximum data storage capacity provided by the 1746-BAS for user programs?

A: The module offers 24 kilobytes of Random Access Memory, backed up by battery.

Wiring & Installation:

Q: What is the primary difference between the two communication ports on the 1746-BAS?

A: Port A is typically configured for RS-232/423, while Port B is designed for RS-422/485 and DH-485.

Troubleshooting & Compatibility:

Q: What diagnostics can be determined if the FAULT indicator LED is continuously illuminated?

A: A continuous FAULT light indicates a BASIC program execution error or a hardware failure within the module.

Replacement & Upgrades:

Q: What is the recommended modern platform replacement for the functionality offered by the 1746-BAS?

A: Use newer ControlLogix or CompactLogix communication modules and programming methods.