1. Product Overview

• Model: MVI46‑MCM

• Manufacturer: ProSoft Technology (inRAx series)

• Platform: Allen‑Bradley SLC 500 (1746 chassis, single‑slot)

• Function: High‑performance Modbus RTU/ASCII serial communication module enabling SLC 500 PLCs to connect to Modbus networks as master, slave, or mixed mode.

• Data Exchange: 5000‑word shared register space between SLC (M0/M1 files) and Modbus devices.

2. Key Features

• Three serial ports:

  • P1, P2: RS‑232/422/485 (software selectable)

  • CFG: RS‑232 RJ45 for configuration/debug

• Dual‑protocol support: Modbus RTU (default) or ASCII

• Master mode: Up to 100 configurable commands; supports all standard Modbus function codes

• Slave mode: Responds to Modbus read/write requests; configurable slave address

• Independent processor: No impact on SLC CPU load

• Isolated ports: Electrical isolation between channels and backplane

• Diagnostic LEDs: PWR, RUN, BP LINK, P1 ACT, P2 ACT

• Compatible with: SLC 5/02 (M0/M1 capable) or newer processors

3. Technical Specifications

General

• Slot usage: 1 slot (1746 local/extended rack)

• Backplane current: 800 mA @ 5.1 VDC

• Data mapping: M0/M1 files (SLC ↔ Modbus)

• Configuration: RJ45 RS‑232 port (CFG)

Serial Communication (P1/P2)

• Interfaces: RS‑232, RS‑422, RS‑485 (software selectable)

• Baud rate: 1200–115.2 kbps

• Data bits: 7 or 8

• Parity: None, Even, Odd

• Stop bits: 1 or 2

• Protocol: Modbus RTU or ASCII

Environmental

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

• Storage temp: -40°C to +85°C (-40°F to 185°F)

• Humidity: 5%–95% non‑condensing

• Vibration: 5 g (10–150 Hz)

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

4. LED Indicators

• PWR: On = backplane power OK

• RUN: On = module operational; flashing = firmware activity

• BP LINK: On = backplane communication active

• P1 ACT / P2 ACT: Flashing = data traffic on port 1/2

5. Installation & Configuration

1. Power off the SLC 500 chassis.

2. Insert MVI46‑MCM into an empty 1746 slot.

3. Connect Modbus devices to P1/P2; connect PC to CFG port for setup.

4. Power on; verify module recognition in RSLogix 500.

5. Configure ports (baud rate, parity, protocol) and master/slave mode via ProSoft configuration software.

6. Map SLC M0/M1 data to Modbus registers using sample ladder logic.

7. Download configuration and test communication.

6. Applications

• Connect SLC 500 to Modbus RTU/ASCII devices: drives, meters, sensors, HMIs

• Integrate third‑party Modbus equipment into Rockwell systems

• Legacy SLC modernization for serial Modbus networking

• SCADA/MMI data collection via Modbus

• Multi‑drop RS‑485 networks for factory floor devices

7. Advantages

• Dual‑port + multi‑mode flexibility: master/slave/RTU/ASCII in one module

• Large 5000‑word data buffer: handles complex data exchange

• Electrical isolation: protects against ground loops and noise

• No SLC CPU overhead: dedicated communication processor

• Proven compatibility: fully tested with Rockwell SLC 500 systems