Overview
The Allen-Bradley 1746-BAS is a single-slot BASIC language module designed for SLC 500 fixed or modular controller chassis. This specialty communication and programming module extends SLC 500 system capabilities by adding BASIC-language programmability, data collection, and advanced serial communication for integration with external devices. It fits standard 1746 backplane slots and communicates seamlessly with all rack-mounted SLC processors including SLC 5/02, 5/03, 5/04, and 5/05.
Key Features
- 24 KB Battery-Backed RAM — Non-volatile storage for user BASIC programs and data sets with capacitive backup during battery replacement
- Dual Serial Ports (PRT1 & PRT2) — RS-232/423, -422, -485 communication ports for connection to modems, printers, Human Machine Interface and other devices
- DH-485 Network Integration — DH-485 port for connecting the module to a DH-485 network using the 1747-AIC link coupler
- DF1 Protocol Support — PRT2 can additionally operate using the DF1 protocol, and when used in DF1 modem mode, the onboard DH-485 port is disabled
- LED Status Indicators — Diagnostic LEDs for module activity, communication, fault status, and battery condition simplify troubleshooting
- BASIC Language Support — Onboard processor supports report generation, string handling, data logging, and machine-level integration tasks not native to standard SLC processors
Technical Specifications
- Memory: 24 KB battery-backed RAM
- Power Supply Loading: 0.150 at 5 Volts DC and 0.040 at 24 Volts DC
- Communication Ports: RS-232/423, RS-422, RS-485 and DH-485 ports with a maximum communication distance of 1230 meters
- Data Transfer: 8 input words and 8 output words for SLC 5/01 processors and higher
- Slot Configuration: Single slot module used in SLC 500 modular or fixed style hardware
- Operating Temperature: 32–140 °F operating temperature range
Typical Applications
This module is widely used for data collection, printer formatting, barcode integration, custom communication drivers, and serial-device interfacing—making it a flexible, powerful addition to any SLC 500 system. Additional uses include:
- Remote data acquisition and monitoring
- Plant-floor integration with external systems
- Operator interface and HMI communication
- Report generation and logging applications
- Legacy DH-485 network connectivity
Compatibility & Replacements
The module communicates with every rack-mounted SLC processor, including the SLC 5/02, 5/03, 5/04, and 5/05. The 1746-BAS is a Basic Language Module that has lower speed capability compared to the 1746-BAS-T. In existing applications, the modules are interchangeable however, a system running with 1746-BAS and replaced with 1746-BAS-T may require program adjustments. The 1746-BAS is programmed using Rockwell Automation’s RSLogix 500 software, the standard programming platform for SLC 500 systems.
