Allen-Bradley 1784-KTX Communication Interface Card

Configured for high-speed data exchange in legacy industrial computing environments, the Allen-Bradley 1784-KTX (1784-KTX Communication Interface Card) provides direct physical execution of DH+ and DH-485 network protocols. This hardware acts as a bridge between ISA-bus equipped host systems and Data Highway networks, facilitating deterministic communication for remote I/O scanning and direct connectivity to PLC-2 and PLC-3 platforms.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks & Firmware Flash Compatibility

The 1784-KTX operates on the legacy ISA bus architecture, which lacks the dynamic plug-and-play resource allocation found in modern PCI systems. Deterministic communication on the DH+ and DH-485 links requires fixed IRQ and memory address mapping to avoid bus contention with other hardware peripherals. Firmware flash compatibility is limited to the legacy drivers supplied for the specific host operating system. When utilized as a remote I/O scanner, the card must maintain consistent scan cycles; any interruption in the host bus communication will trigger a fault state in the connected remote I/O racks, resulting in a loss of deterministic data exchange.

Frequently Asked Questions

Q: Does the 1784-KTX support hot-swapping within the ISA bus?

A: No. The ISA bus architecture does not support live insertion or removal of expansion cards. Power must be removed from the host PC chassis before installing or extracting the 1784-KTX to prevent permanent damage to the card or the motherboard bus interface.

Q: Is it possible to use this card in a PCI-to-ISA bridge slot?

A: Operation in a PCI-to-ISA bridge is not guaranteed. Due to the strict timing requirements of the DH+ protocol, hardware-level bus bridges often introduce latencies that compromise deterministic performance and may lead to communication timeouts with the PLC.

Field Installation Guidelines

• Bus Seating: Ensure the card is fully seated in the ISA slot. Verify that the card bracket is securely screwed into the chassis to provide mechanical stability and a stable earth ground reference.
• Jumper Configuration: Configure the hardware jumpers for the correct IRQ and I/O address range before initialization. Mismatched settings will result in bus conflicts and system boot failures.
• Shielding: Use shielded DH+ or DH-485 cabling to connect the card to the network. The cable shield must be terminated to a clean chassis ground at the entry point of the electrical cabinet to suppress high-frequency noise common in legacy industrial environments.
• Power Supply: Ensure the host PC power supply provides a stable 5 VDC rail. Given the 600 mA draw, avoid overloading the 5 VDC branch with multiple expansion cards, as voltage drops can result in intermittent communication errors on the DH+ link.