PLCs, Power Supplies & Others

Seamless Connectivity for DSI and Modbus Devices

The Allen-Bradley 1769-SM2 bridges CompactLogix controllers with DSI and Modbus networks. This communication module belongs to the 1769 Compact I/O family from Rockwell Automation. It connects AC drives, motor starters, and other serial devices to the control system. Engineers select this unit for drive integration without additional network infrastructure.

Detailed Technical Specifications

This section presents the complete technical parameters of the Allen-Bradley 1769-SM2. We emphasize precise communication characteristics and electrical ratings for accurate system integration. The design prioritizes protocol flexibility and reliable connectivity.

Physical Dimensions & Weight

Accurate physical data supports proper cabinet layout and DIN rail configuration. The Allen-Bradley 1769-SM2 features a compact form factor for efficient space utilization.

• Dimensions (H x W x D): 118 mm x 35 mm x 87 mm

• Weight: 0.19 kg

• Origin: Made in USA (Rockwell Automation Manufacturing Facilities)

Protocol Architecture and Compatibility

The module supports both DSI (Drive Serial Interface) and Modbus RTU protocols. DSI provides native connectivity to PowerFlex drive families. Modbus RTU enables communication with third-party devices and instruments. This dual-protocol capability reduces the need for multiple communication modules.

Serial Communication Interface

A single RS-485 port provides multi-drop connectivity for up to 31 devices with repeaters. Users select baud rates from 9600 bps to 115200 bps for network optimization. The interface supports both 2-wire and 4-wire configurations. This flexibility accommodates various installation requirements and device types.

Drive Integration Capabilities

The 1769-SM2 connects directly to PowerFlex 4, 40, 400, 40P, 70, and 700 series drives. Users can read drive parameters, monitor status, and issue control commands. The module handles start, stop, speed reference, and fault reset functions. Consequently, drives integrate seamlessly without separate communication adapters.

Modbus RTU Connectivity

The module operates as a Modbus RTU master on the serial network. It reads and writes data to Modbus slave devices such as instruments and sensors. Users configure Modbus mapping through the programming software. This capability extends system connectivity beyond Rockwell Automation devices.

Component Layout and Status Indication

The Allen-Bradley 1769-SM2 contains a single PCB assembly with communication processor and isolation circuits. Three front-panel LEDs provide comprehensive status information. A green Power LED confirms proper supply voltage. A Network Status LED indicates active communication. A Module Status LED shows operational condition.

Installation and System Integration

Mounting this module requires a standard 35 mm DIN rail or panel mounting. It connects to CompactLogix and MicroLogix 1500 systems through the 1769 bus. Users can place the module anywhere within the I/O bank. This modular approach allows flexible system expansion.

Configuration and Programming

Configuration occurs through RSLogix 5000 or RSLogix 500 software. Users set protocol selection, baud rate, and node addressing during setup. The module creates tag-based data structures for drive parameters. This integration simplifies programming and reduces development time.

Power Requirements and Energy Efficiency

The module draws 50 mA from the 5 VDC backplane and requires external 24 VDC for the serial port. This low power consumption minimizes impact on system power budgets. Users can power the module from existing 24 VDC supplies. Efficient operation reduces thermal load in control cabinets.

Manufacturer Quality Standards

Allen-Bradley manufactures the 1769-SM2 under strict quality control protocols. Each unit undergoes comprehensive testing for communication integrity and isolation. Therefore, users receive a product ready for immediate deployment. This commitment to quality aligns with Rockwell Automation reliability expectations.

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