Allen-Bradley 1770-KFD PLC-5 DeviceNet RS-232 Communication Interface Module

Description

The Allen-Bradley 1770-KFD is a portable, standalone DeviceNet RS-232 Communication Interface Module designed to provide personal computers and programming workstations direct serial access to a DeviceNet industrial network. Operating as an external communication gateway, the module bridges standard RS-232 serial ports with DeviceNet field networks, enabling system integrators, control engineers, and maintenance personnel to perform online network monitoring, device configuration, node commissioning, and diagnostic procedures across distributed automation architectures.

Functioning within Allen-Bradley PLC-5, SLC 500, and CompactLogix automation environments, the 1770-KFD facilitates communication either in a point-to-point configuration directly connected to a single field device or across a multi-node DeviceNet trunkline. The module executes local network management routines and protocol conversion between RS-232 framing and DeviceNet CAN-based messaging, allowing software applications such as DeviceNet Manager or RSLinx to interface with scanners, I/O blocks, drives, and intelligent sensors across the network.

Built with a compact desktop enclosure and optional DIN rail mounting brackets, the 1770-KFD features dual power sourcing flexibility. It can operate directly from the 24V DC bus provided by the DeviceNet network connection or via an external 9V DC wall adapter. Status LEDs provide continuous visual feedback for module diagnostics and network bus state, streamlining field service, network troubleshooting, and parameter backup operations.

Features

• Serial to DeviceNet Protocol Conversion: Converts standard RS-232 serial data frames into DeviceNet CAN-based messages for PC-based commissioning and parameter management.
• Dual Operation Modes: Supports point-to-point direct configuration with an individual network device as well as full multi-drop access across an active DeviceNet network segment.
• Flexible Sourcing Options: Operates using power drawn directly from the DeviceNet network cable (11 to 25V DC) or through an external 9V DC power supply adapter.
• Selectable Communication Baud Rates: Features RS-232 transmission speeds up to 57,600 baud and DeviceNet network data rates selectable at 125k, 250k, and 500k baud.
• Point-to-Point Power Delivery: Capable of supplying 12V DC power (up to 100 mA) to a connected field device during direct point-to-point setup sessions.
• Diagnostic LED Indicators: Integrated visual indicators provide real-time status monitoring for module power, operational health, and DeviceNet communication activity.
• Portable and DIN-Rail Mountable: Lightweight, compact enclosure suitable for benchtop service work or permanent cabinet mounting using included DIN rail adapters.

Applications

• Field Device Commissioning: Direct point-to-point parameter configuration of DeviceNet smart sensors, motor starters, drives, and remote I/O modules prior to network installation.
• Network Diagnostics and Monitoring: Online bus monitoring, message traffic inspection, and node address verification using PC-based software like DeviceNet Manager.
• PLC System Maintenance: Interface point for servicing DeviceNet scanner networks managed by Allen-Bradley PLC-5 (1771-SDN), SLC 500 (1747-SDN), or CompactLogix (1769-SDN) controllers.
• Parameter Backup and Restore: Uploading and downloading device profiles, node configurations, and operational parameters during field hardware replacements.

Technical Specifications

General

Communication Parameters

Electrical Requirements

Environmental

Connections / Interfaces

Installation Guidelines

1. Safety Precaution: Verify that all electrical power sources are disconnected or de-energized according to industrial safety protocols before modifying control panel wiring.
2. Mounting: Use the module as a portable desktop unit, or install the provided DIN rail mounting brackets using the four mounting screws to attach the module onto a standard 35 mm DIN rail inside a enclosure.
3. Serial Cable Connection: Connect the 9-pin D-shell RS-232 port on the module to an available serial COM port on the host workstation using a standard 9-pin null-modem cable.
4. DeviceNet Bus Connection: Wire the 5-pin unsealed DeviceNet terminal connector to the network drop cable, ensuring proper pin assignment matching for signal (CAN_H, CAN_L), power (V+, V-), and drain/shield lines.
5. Power Source Verification:
   • For network-powered operation, ensure the active DeviceNet bus provides between 11V DC and 25V DC across the V+ and V- terminals. Note that active network power overrides external power input.
   • For standalone benchtop setup, connect the approved 9V DC wall adapter into the DC power jack.
6. Grounding: Ensure proper shielding and signal grounding principles are maintained along the DeviceNet network drop line to prevent noise interference.

Configuration / Commissioning / Replacement

Configuration Guidelines

• Install the appropriate 1770-KFD driver software or serial driver within RSLinx / DeviceNet Manager on the PC host.
• Match the driver serial baud rate setting in software to the physical switch/software selection configured on the 1770-KFD module (up to 57,600 baud).
• Ensure the target DeviceNet network transmission rate (125k, 250k, or 500k baud) matches the operational baud rate of all nodes connected to the bus.

Commissioning & Diagnostics

• Observe the module status LEDs upon powering the unit. Verify stable power illumination and normal communication toggling on both serial and network lines.
• Perform node detection scanning from the workstation software to confirm online visibility of connected DeviceNet field devices or PLC scanner modules (such as 1771-SDN, 1747-SDN, or 1769-SDN).

Replacement Recommendations

• When replacing an existing 1770-KFD interface module, confirm that serial driver configurations and baud rate selections in RSLinx or host software match previous system parameters.
• Disconnect the DeviceNet terminal block from the old module and plug it directly into the replacement unit without altering individual wire terminations.