Allen-Bradley 1747-KE/C DH-485 Interface Module

The Allen-Bradley 1747-KE/C, also cataloged as the 1747-KE/C communication interface module, serves as the primary DH-485 and RS-232C protocol bridge utilized to execute serial network interconnection and DF1 translation across Rockwell Automation SLC 500 platforms. The module provides direct electrical and protocol-level conversion between DH-485 token-passing networks and DF1-based serial devices, including modem-connected endpoints.

Suffix Breakdown & Model Matrix

The “/C” suffix denotes the Series C hardware revision of the 1747-KE interface architecture. No further functional segmentation or configurable variant structure is defined within this model identifier.

Hardware Specifications

Serial Protocol Translation and DH-485 Token Passing Network Architecture

Within Rockwell Automation SLC 500 communication layers, the 1747-KE/C implements deterministic protocol bridging between DF1 serial streams and DH-485 token-passing networks. The module performs frame-level conversion without altering application-layer ladder logic execution, ensuring consistent memory image mapping across heterogeneous serial endpoints.

The DH-485 interface operates on a token-passing arbitration mechanism, where node access is governed by sequential token ownership rather than collision-based transmission. The 1747-KE/C maintains synchronized participation in this cycle while simultaneously translating DF1 ASCII/binary frames received via RS-232/RS-485 physical layers.

Backplane integration allows configuration access through ASCII terminal sessions or direct SLC chassis communication, enabling runtime parameter adjustment including baud rate selection and node addressing. Isolation on the CONFIG port (500 V DC) provides separation between external serial equipment and internal backplane logic domain.

Frequently Asked Questions (FAQ)

Q: Does the 1747-KE/C execute PLC logic or modify ladder programs internally?
A: No. The module only performs protocol bridging and does not execute or store control logic.

Q: Can DH-485 and DF1 communications operate simultaneously?
A: Yes. The module supports concurrent handling of DH-485 network traffic and DF1 serial communication through separate ports.

Q: Is the module hot-swappable within the SLC 500 chassis?
A: No. Insertion or removal must be performed with chassis power removed to avoid backplane communication disruption.

Field Installation Guidelines

The module shall be installed in a dedicated SLC 500 chassis slot with system power fully removed prior to insertion. Backplane connector alignment must be verified to ensure correct seating and communication integrity.

Serial cabling must follow RS-232/RS-485 wiring standards depending on selected port configuration. Shielded twisted pair conductors are required for DH-485 segments, with single-point grounding to avoid ground loop formation.

Modem-connected DF1 applications require correct baud rate matching across all endpoints. Cable routing must be separated from high-voltage conductors to minimize induced noise on low-voltage serial lines.