Purchase now: Allen Bradley 1747-KE Interface Module
Purchase now: Atlantechdrives provides you the 1747-KE, a highly specialized communication interface module engineered by Allen Bradley for the legacy SLC 500 automation platform. This module acts as an intelligent protocol bridge, seamlessly translating data between a local DH-485 (Data Highway 485) network and RS-232C standard serial devices using the DF1 protocol (Full-Duplex or Half-Duplex). The 1747-KE is an essential piece of hardware for remote telemetery applications, allowing you to connect industrial dial-up modems, radio transceivers, third-party SCADA systems, or older programming terminals directly to the SLC backplane. By sitting in the chassis, it enables long-distance data acquisition and remote programming capabilities that standard processor ports cannot natively handle over wide area networks.
Technical Specifications of the 1747-KE
The 1747-KE is a single-slot module that draws its operating power directly from the SLC chassis backplane. It features a robust RS-232C port (configured as DTE) and relies on internal configuration to negotiate baud rates and error-checking protocols.
- Part Number: 1747-KE
- Module Type: Communication Interface Module
- Compatible System: Allen Bradley SLC 500
- Network 1 (Backplane): DH-485 Token Passing
- Network 2 (Front Port): RS-232C (DF1 Protocol)
- Supported Baud Rates: 300 to 19200 bps
- DF1 Modes: Full-Duplex, Half-Duplex Master, Half-Duplex Slave
- Backplane Current Draw: 150 mA at 5V DC, 40 mA at 24V DC
- Configuration: Software-based via internal EEPROM
Expert Installation Advice: Modem Handshaking and Configuration
Integrating a radio or dial-up modem with the 1747-KE requires a deep understanding of serial handshaking. Expert Tip: Unlike modern Ethernet, RS-232 communication over a modem introduces significant latency. If you are configuring the 1747-KE for DF1 Half-Duplex over a radio link, you must accurately configure the «RTS Send Delay» and «RTS Off Delay» parameters inside the module’s setup. If the KE module sends data before the radio transmitter has fully keyed up, the first few bytes of the data packet will be lost, resulting in endless CRC errors and dropped communication. Additionally, ensure you are using a standard Null Modem cable (like the 1747-CP3) if connecting directly to a PC, but a straight-through serial cable if connecting to a standard DCE modem.
Maintenance and Configuration Retention
The 1747-KE stores its critical port configuration parameters (baud rate, node address, parity) in a built-in EEPROM, meaning it will retain its setup even during a power outage without requiring a backup battery. If a 1747-KE fails in the field, simply inserting a new module is not enough; you must use the specialized KF2/KE configuration software (often accessed via RSLinx or legacy DOS tools) to download the specific DF1 and DH-485 parameters into the replacement module before it will successfully bridge the networks.
Frequently Asked Questions (FAQs)
Q: Can I use the 1747-KE to program the PLC if the processor port is broken?
A: Yes. You can connect your laptop to the 1747-KE’s RS-232 port using RSLinx with the DF1 driver. The KE module will route your RSLogix 500 programming commands through the backplane to the processor via the DH-485 network.
Q: Does this module support Ethernet/IP?
A: No. The 1747-KE is strictly for legacy serial RS-232 (DF1) and DH-485 networks. For Ethernet, you must use a 1747-ENET module or upgrade to an SLC 5/05 processor.
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This DH-485 to RS-232 interface module is used to bridge communications for legacy SLC 5/01 controllers.
