Allen-Bradley 1747-KFC15 Replacement for SLC 500

Product Overview

Allen-Bradley 1747-KFC15 Replacement for SLC 500: Seamless Migration & Upgrade Solution

The Allen-Bradley 1747-KFC15 is a Serial Communication Interface Module designed for the SLC 500 programmable controller platform. As legacy SLC 500 systems approach end-of-life and original 1747-KFC15 units become increasingly difficult to source, plant engineers and maintenance teams face mounting pressure to maintain uptime without triggering a full control system overhaul. TOPNLMS supplies tested, ready-to-ship 1747-KFC15 modules that enable a smooth, low-risk transition — preserving your existing SLC 500 rack architecture, wiring infrastructure, and RSLogix 500 programming investment while restoring full serial communication capability.

The 1747-KFC15 occupies a standard SLC 500 I/O slot and provides an RS-232C serial port that supports DF1 Full-Duplex, DF1 Half-Duplex Master/Slave, and DH-485 protocol communication. It is fully compatible with the 1746 modular chassis family — including the 1746-A4, 1746-A7, 1746-A10, and 1746-A13 rack sizes — and interfaces directly with SLC 5/03, SLC 5/04, and SLC 5/05 processors. When replacing a failed or end-of-life 1747-KFC15, no re-racking, no chassis modification, and no processor firmware upgrade is required. The module slides into the existing slot, and communication parameters are restored through RSLogix 500 channel configuration — typically within one engineering shift.

For sites running mixed communication architectures, the 1747-KFC15 is commonly deployed alongside the 1747-SDN DeviceNet Scanner Module to bridge legacy serial devices with newer DeviceNet field instruments, allowing a phased migration rather than a disruptive cutover. Similarly, sites that have already upgraded their processor to a SLC 5/05 can retain the 1747-KFC15 for dedicated RS-232 peripheral connections — such as barcode readers, weigh scales, or third-party HMI panels — while the onboard Ethernet port handles supervisory SCADA traffic. This dual-path communication strategy significantly reduces the scope and cost of modernization projects.

Wiring compatibility is a critical concern during any module swap. The 1747-KFC15 uses a standard DB-9 RS-232C connector, which is mechanically and electrically identical across all production revisions of this module. Existing cable assemblies, null-modem adapters, and RS-232-to-RS-485 converters used with the original unit can be reused without modification. For installations where the serial link connects to a Panel View 550 or Panel View 900 HMI terminal, the DF1 Full-Duplex configuration is retained without any HMI-side reconfiguration, minimizing operator retraining and validation effort.

Power consumption of the 1747-KFC15 draws from the SLC 500 chassis backplane — 130 mA at 5 VDC — which is within the power budget of all standard 1746 power supply modules, including the 1746-P1, 1746-P2, and 1746-P4. No external power wiring is required. For sites where the existing power supply is already near capacity due to the addition of analog I/O modules such as the 1746-NI4 or 1746-NO4I, a power budget review is recommended before installation, though in the vast majority of standard rack configurations this is not a constraint.

From a program migration standpoint, the channel configuration data stored in the SLC 500 processor’s data file is preserved when the module is replaced with an identical 1747-KFC15. There is no need to re-enter baud rate, parity, stop bits, or protocol selection parameters if the replacement module is installed in the same slot. RSLogix 500 MSG instructions referencing the channel remain valid. For sites that have archived their ladder logic programs, a simple online upload confirms configuration integrity before returning the system to production.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful 1747-KFC15 replacement rarely happens in isolation. In most SLC 500 retrofit projects, the communication module swap is one step in a broader system stabilization effort. Engineers sourcing the 1747-KFC15 frequently require companion components to complete the upgrade without extending downtime.

For sites where the SLC 500 processor itself is also approaching end-of-life, the 1747-L553 SLC 5/05 processor with onboard Ethernet is a common upgrade path that retains the existing 1746 chassis and I/O wiring while adding modern network connectivity. The 1747-KFC15 can continue to serve dedicated serial peripheral connections on the same rack during and after this processor upgrade, providing a bridge between legacy serial devices and the new Ethernet-enabled architecture.

Discrete I/O modules such as the 1746-IB16 (16-point 24 VDC input) and 1746-OB16 (16-point 24 VDC output) are frequently replaced in the same maintenance window as the communication module, since field wiring is already partially disconnected. Sourcing these alongside the 1747-KFC15 reduces the number of planned outages required. Similarly, analog modules including the 1746-NI4 four-channel analog input and 1746-NO4I four-channel analog output are common co-sourcing items for process control applications where signal integrity must be verified after any rack disturbance.

For installations where the 1747-KFC15 connects to a remote programming terminal or SCADA workstation via RS-232, the 1747-CP3 programming cable is often required to re-establish the RSLogix 500 connection during commissioning. Having this cable on-site before the maintenance window begins eliminates a common source of commissioning delay. Where the serial link bridges to a DH-485 network segment, the 1747-AIC Advanced Interface Converter provides the RS-232-to-DH-485 signal conversion that many multi-drop SLC 500 network topologies depend on.

Power supply integrity is another area that maintenance teams address during a communication module replacement. The 1746-P2 power supply (5 VDC / 24 VDC, 5A) and 1746-P4 (5 VDC / 24 VDC, 10A) are the most common replacement power supplies for mid-size and large SLC 500 racks. Replacing an aging power supply in the same outage window as the 1747-KFC15 is a best practice that reduces the risk of an unplanned outage caused by power supply degradation in the months following the communication module repair.

Retrofit Guidance FAQ

Q: Can I replace the 1747-KFC15 without modifying my RSLogix 500 program?
A: Yes. If the replacement module is installed in the same chassis slot, the channel configuration stored in the processor data file remains valid. No MSG instruction edits or channel reconfiguration are required in the vast majority of installations. A brief online verification after power-up is recommended to confirm communication status bits.

Q: Is the DB-9 wiring from my original 1747-KFC15 reusable?
A: Yes. The RS-232C DB-9 connector pinout is identical across all production revisions of the 1747-KFC15. Existing cable assemblies, including null-modem cables and RS-232-to-RS-485 adapters, can be reconnected without modification.

Q: Does the 1747-KFC15 support both DF1 and DH-485 simultaneously?
A: No. The module’s single RS-232C port operates in one protocol mode at a time, selected via RSLogix 500 channel configuration. The protocol can be changed in software without hardware modification.

Q: Will the 1747-KFC15 fit in any slot of my 1746 chassis?
A: Yes. The module occupies one standard I/O slot and is compatible with all 1746 chassis sizes (A4, A7, A10, A13). It does not need to be installed in a specific slot position.

Q: What baud rates does the 1747-KFC15 support?
A: The module supports 1200, 2400, 4800, 9600, and 19200 bps, configurable via RSLogix 500. The baud rate must match the connected device for reliable communication.

Q: How do I verify the module is communicating correctly after installation?
A: Monitor the module’s status LED indicators and check the channel status bits in the SLC 500 processor data file using RSLogix 500 online monitoring. A successful DF1 link will show the TX and RX LEDs active during message exchange.

Q: Can the 1747-KFC15 be used with a SLC 5/01 or SLC 5/02 processor?
A: The 1747-KFC15 is designed for SLC 5/03, 5/04, and 5/05 processors. SLC 5/01 and 5/02 processors do not support the channel configuration required for this module’s protocol modes.

Warranty Assurance

Every 1747-KFC15 module shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to shipment, each unit undergoes functional verification including backplane communication testing, serial port continuity checks, and visual inspection for component and connector integrity. Units that do not pass inspection are not shipped.

In the event of a warranty claim, TOPNLMS provides a replacement unit or full refund based on the customer’s preference and the nature of the fault. Our technical support team responds to warranty inquiries within one business day. Customers are not required to return the defective unit before a replacement is dispatched for critical production applications — contact us to arrange expedited replacement under our downtime-priority protocol.

All orders are shipped with tracking from our Xiamen warehouse. Standard international shipping typically delivers within 5–12 business days depending on destination. Expedited DHL and FedEx options are available for urgent requirements. Export documentation, including commercial invoice and packing list, is provided with every shipment to facilitate customs clearance.

TOPNLMS maintains stock of the 1747-KFC15 and related SLC 500 components to support both planned maintenance schedules and emergency breakdown sourcing. Bulk order pricing is available for MRO procurement teams managing multi-site SLC 500 fleets.