Description

The Woodhead PCU-DPIO (global Molex part number 1120115024, historically branded under SST or BradCommunications) is a single-channel, high-performance industrial network interface card (NIC) designed for standard Universal PCI bus slots. Equipped with an onboard communications co-processor, it offloads real-time network protocol execution from the host PC’s CPU. This ensures deterministic, high-speed Profibus-DP Master or Slave data exchanges with localized field equipment such as remote I/O, variable frequency drives (VFDs), and process instrumentation.

Commercial Availability & Logistics

Technical Specifications

Core Hardware Architecture & Performance

The PCU-DPIO interface module handles all low-level layer-2 frame packaging, timing constraints, and token rotation management directly on the board, eliminating the OS-level latency bottlenecks common in software-driven network emulation:

Automatic Dual-Port RAM Mapping (ADM)

The card utilizes a proprietary ADM memory allocation scheme. Rather than requiring the field engineer to manually calculate, segment, and assign physical base addresses or memory offsets, the card’s software utility automatically maps the input/output tags directly inside the physical Dual-Port RAM boundaries. This feature mitigates register overlap errors and shortens commissioning times.

Diagnostic & Safety Watchdog Supervision

Beyond standard cyclical I/O data capture, the embedded microcontroller continuously delivers real-time diagnostic parameters to the host application:

• Network Telemetry: Tracks communication error counters, packet retries, and slave presence maps, feeding them directly to the SCADA interface.
• Fail-Safe Watchdog: Features parallel software and hardware watchdogs. If the host PC operating system encounters a “blue screen” or application hang, the card automatically disengages its network connections and signals downstream nodes to enter a designated fail-safe state.

Field Integration & Configuration Best Practices

When deploying or replacing a PCU-DPIO (1120115024) card within an active PC-based industrial controller or panel PC, adhere to standard backplane maintenance protocols:

PCI Slot Keying and Clearance

The Universal PCI interface board features edge-connector notches that make it mechanically compatible with both legacy 5V PCI slots and newer 3.3V PCI-X or standard PCI lanes.

Critical Field Note: Prior to sliding the card into the slot, ensure the industrial PC is completely powered down at the mains isolator. Ground yourself with an ESD wrist strap. When seating the card into the motherboard, verify that the card’s gold edge connector pins align cleanly within the keying blocks before applying downforce. Misaligned pins can bridge power lines, causing electrical overstress that can destroy the motherboard’s southbridge controller.

Driver and Configuration Sync

1. Install the core BradCommunications / Molex console driver utilities and software servers prior to physically seating the hardware board into the slot.
2. Ensure that the identical .GSD network definition databases used by the original network setup are imported into the configuration console utility to preserve device mapping offsets.
3. If the host system fails to discover the card upon boot, access the system BIOS configuration utility and confirm that the slot is not sharing an un-routable Interrupt Request line (IRQ conflict) with an adjacent device like a video card or network interface card.

Frequently Asked Questions

Q: What is the relation between Molex, Woodhead, SST, and the part number 1120115024?

Over time, the product’s branding changed due to corporate acquisitions. Originally engineered by SST (System Technology) and subsequently marketed by Brad Communications and Woodhead Industries, all of these entities were eventually integrated into Molex. The number 1120115024 is the standardized Molex global part number used to track and order this exact PCU-DPIO module across modern supply networks.

Q: Can this card be mounted inside a modern PCI Express (PCIe) slot?

No. The PCU-DPIO is built exclusively for standard parallel PCI architectures (featuring a wider, multi-pin connector pattern). For newer industrial controllers equipped with short, high-speed serial PCI Express expansion paths, you must specify the PCIE-DPIO variant, which features the matching mechanical form-factor and PCIe chip bridge architecture.

Q: Why is the Profibus network dropping packets or failing to communicate at 12 Mbps?

High-speed Profibus runs are highly sensitive to bus capacitance and termination. Verify that the standard DB9 fieldbus connectors at both ends of the segment have their integrated termination resistors switched ON, and that all intermediate nodes have their resistors turned OFF. Additionally, ensure that the network cabling uses shielded twisted-pair (Type A Profibus cable) and that the shield makes solid contact with the metal shell of the 1120115024 card’s DB9 port to bleed off environmental noise.