1. Product Overview

• Model: MVI56‑BAS

• Manufacturer: ProSoft Technology (inRAx series)

• Platform: Allen‑Bradley ControlLogix (1756 chassis, single‑slot)

• Core Function: BASIC‑52 programmable module; migrates legacy 1771‑DB / 1747‑BAS BASIC programs to ControlLogix.

• Purpose: Custom serial/ASCII/DF1 communications, protocol conversion, and standalone logic offloaded from PLC.

• Integration: High‑speed backplane I/O with ControlLogix tags; CF card for program storage/backup.

2. Key Features

• BASIC‑52 programming: 24,065 bytes RAM for user code; supports math, strings, I/O, serial comms.

• Three onboard ports:

  • CFG: RS‑232 for programming/debug

  • PRT1: RS‑232/422/485 (ASCII / DF1)

  • PRT2: RS‑232/422/485 (ASCII / DF1)

• DF1 support: Full‑duplex or half‑duplex slave (Rockwell protocol).

• DH‑485 port: Connect to legacy SLC 500 / DH‑485 devicesProSoft Technology Inc.

• ASCII device interface: Modems, printers, scanners, scales, serial instruments.

• CF card slot: Store/load BASIC programs; easy backup/restore.

• LEDs: PWR, RUN, BP LINK, PORT ACT (per port).

• Approvals: CE, UL/cUL, CSA, ATEX, RoHS; Class 1 Div 2.

3. Technical Specifications

General

• Slot usage: 1 slot (1756 local/remote rack)

• Backplane current: 800 mA @ 5.1 VDC; 3 mA @ 24 VDCProSoft Technology Inc

• User RAM: 24,065 bytes (BASIC program + data)

• Program storage: CompactFlash (FAT16)

• Configuration: ProSoft Configuration Builder (PCB) + BASIC editor

Communication Ports

• CFG (RS‑232): 9.6–115.2 kbps; programming/debug

• PRT1/PRT2 (RS‑232/422/485): 1.2–115.2 kbps; ASCII/DF1

• DH‑485: 19.2 kbps; SLC 500 / DH‑485 networkProSoft Technology Inc

• Isolation: 500 V optical isolation (ports ↔ backplane)

Environmental

• Operating temp: 0°C to +60°C (32°F to 140°F)ProSoft Technology Inc

• Storage temp: ‑40°C to +85°CProSoft Technology Inc

• Humidity: 5%–95% non‑condensing

• Vibration: 5 g (10–150 Hz)ProSoft Technology Inc

• Shock: 30 g (operational), 50 g (non‑operational)ProSoft Technology Inc

4. LED Indicators

• PWR: On = backplane power OK

• RUN: On = module active; flashing = BASIC program running

• BP LINK: On = backplane I/O exchange active

• PRT1/PRT2/CFG ACT: Flashing = serial data traffic

5. Typical BASIC Applications

• Legacy migration: Reuse 1771‑DB / 1747‑BAS code in ControlLogix.

• Custom serial protocols: Build drivers for non‑standard ASCII devices.

• Data concentrators: Poll multiple serial instruments; pass data to PLC.

• Protocol converters: ASCII ↔ DF1; serial ↔ backplane tags.

• Standalone math/logic: Run complex calculations independent of PLC scan.

• Printer/logger interfaces: Direct serial printing, data logging to CF card.

6. Advantages

• Legacy code reuse: Protects investment in existing BASIC programs.

• Offloads PLC: Runs serial comms & math without slowing ladder logic.

• Highly flexible: BASIC‑52 enables custom logic not possible with standard modules.

• Cost‑effective: Eliminates need for external PCs/gateways for simple serial tasks.

• Seamless Rockwell integration: Native backplane I/O, no custom drivers.