Description:The Allen-Bradley 1784-PKTX is a PCI-bus network interface card (NIC) that enables a standard industrial or office PC to connect directly to legacy Allen-Bradley Data Highway Plus (DH+), Remote I/O (RIO), and DH-485 networks. It serves as a critical bridge for programming, monitoring, and data acquisition with older controllers like the PLC-5 and SLC 500 series, translating PCI bus commands into industrial protocol traffic. Note: This product was officially discontinued by Rockwell Automation on March 31, 2022, and is now primarily sourced through the secondary/refurbished market for legacy system maintenance.Application Scenarios:In a steel mill’s aging melt shop, the central Windows XP-based HMI server running FactoryTalk View needed to poll data from six PLC-5/60 controllers scattered across the facility. The existing 1784-PKTX card installed in the server’s PCI slot provided a single, reliable DH+ connection (configured for 57.6 kbps) that daisy-chained all the PLCs. This allowed operators to monitor furnace temperatures and conveyor statuses in real-time without requiring a costly and disruptive migration to Ethernet/IP.
Parameter:
| Main Parameters | Value/Description |
|---|---|
| Product Model | 1784-PKTX |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Product Category | PCI Network Interface Card (NIC) |
| Host Bus Interface | PCI 2.3 (5V, 32-bit) – Not PCI Express (PCIe) |
| Supported Protocols | Data Highway Plus (DH+), Remote I/O (RIO), DH-485 |
| Communication Ports | 1A: 3-pin Phoenix (DH+/RIO) 1C: 6-pin Phoenix (DH-485) |
| DH+ Baud Rates | 57.6 kbps, 115.2 kbps, 230.4 kbps |
| Max DH+ Distance | 10,000 ft (3048 m) @ 57.6 kbps |
| Power Consumption | ~5V @ 350-500 mA (via PCI slot) |
| Operating Temperature | 0 to 60 °C |
| Compatibility | PLC-5, SLC 5/04, MicroLogix (via DH-485) |
Technical Principles and Innovative Values:The 1784-PKTX functions as a specialized modem, offloading the complex token-passing protocol of DH+ from the PC’s CPU to its onboard processor.
- Innovation Point 1: Multi-Protocol Flexibility on a Single Channel: Unlike fixed-function cards, the 1784-PKTX can be reconfigured in RSLinx Classic to operate as a DH+ adapter, a Remote I/O Scanner, or a DH-485 interface. This “three-in-one” design drastically reduced the variety of spare parts maintenance teams needed to stock for different legacy networks.
- Innovation Point 2: PCI Plug-and-Play Architecture: As a successor to the older ISA-bus 1784-KTX, the PKTX leveraged the PCI standard’s Plug-and-Play (PnP) capabilities. It automatically configures its IRQ and base memory address, eliminating the manual jumper settings and hardware conflicts that plagued earlier industrial PC cards.
- Innovation Point 3: Deterministic RIO Scanning: When configured for Remote I/O, the card operates at the hardware level to poll remote I/O racks with high determinism. This allows a PC-based control system (e.g., using SoftLogix) to function as a master scanner, ensuring timely I/O updates independent of the Windows operating system’s non-real-time latency.
