Description:The Allen-Bradley 1784-PKTX B/A is a PCI-based network interface card (NIC) designed to provide a critical communication bridge between a standard industrial PC and Allen-Bradley’s legacy Data Highway Plus (DH+), Remote I/O, and DH-485 networks. As a core component for maintaining and servicing aging PLC-5 and SLC 500 systems, this card allows engineers to perform programming, monitoring, and diagnostic tasks directly from a Windows-based workstation, extending the operational life of mission-critical legacy control systems.Application Scenarios:In a steel processing plant in Taiyuan, the core rolling mill control relies on a decades-old PLC-5/40 system running on a DH+ network. The plant’s single engineering workstation, equipped with a 1784-PKTX B/A card, is the only tool capable of going online with the processor to troubleshoot a critical logic fault causing motor overloads. The technician uses the card to connect via RSLinx Classic, upload the latest program backup, and force I/O points to isolate a faulty limit switch—all without disrupting the live production run. This card acts as the indispensable “key” to access the plant’s foundational control infrastructure.
Parameter:
| Parameter | Value / Specification |
|---|---|
| Product Model | 1784-PKTX B/A (Series B or A) |
| Manufacturer | Rockwell Automation (Allen-Bradley) |
| Product Category | PCI Network Interface Card (NIC) |
| Host Bus Interface | PCI 2.3 (32-bit, 5V, 33MHz) |
| Communication Channels | 2 (Channel 1A: DH+/RIO; Channel 1C: DH-485) |
| Supported Protocols | Data Highway Plus (DH+), Remote I/O (RIO), DH-485 |
| DH+ Data Rates | 57.6 kbps, 115.2 kbps, 230.4 kbps |
| DH+ Cable Length | Up to 10,000 ft (3,048 m) @ 57.6 kbps |
| DH-485 Data Rates | 1.2 to 19.2 kbps (Up to 4,000 ft) |
| Connectors | 3-pin Phoenix (Ch 1A), 6-pin Phoenix (Ch 1C) |
| Power Consumption | +5V DC @ ~350 mA (via PCI slot) |
| Operating Temperature | 0°C to 60°C (32°F to 140°F) |
| Status Indication | 1 LED per channel (Diagnostics/Activity) |
Technical Principles and Innovative Values:The 1784-PKTX B/A is engineered to solve the specific challenge of PC integration with proprietary industrial networks that predate modern Ethernet.
- Innovation Point 1: Multi-Protocol Legacy Gateway. Unlike generic serial adapters, this card provides a dedicated hardware-level interface for Allen-Bradley’s token-passing DH+ network (a non-standard RS-422/485 variant). It handles the complex timing and framing of the DH+ protocol, offloading this task from the host PC’s CPU and providing a stable, high-level driver interface for Rockwell software like RSLogix 5 and RSLogix 500. This ensures reliable communication where software-based emulation often fails.
- Innovation Point 2: Plug-and-Play PCI Integration. As a successor to the older ISA-bus KTX cards, the 1784-PKTX leverages the PCI bus standard for automatic resource allocation (IRQ, base address). This eliminates the need for manual jumper settings, reducing installation complexity and potential conflicts in multi-card engineering stations. The card draws power directly from the PCI slot, requiring no external power supply.
- Innovation Point 3: Industrial-Grade Reliability. Designed for the control room environment, the card features a conformal-coated PCB for protection against humidity and dust. Its wide operating temperature range (0-60°C) and robust electrical isolation make it suitable for 24/7 operation in harsh industrial settings, far exceeding the reliability of consumer-grade network adapters.
