Detailed Product Description of XYCOM XVME-202 I. Product Overview

XVME-202 is a 3U single-height VMEbus PAMUX distributed I/O controller module launched by XYCOM (now part of Acromag/Xembedded). Its core function is to bridge the VME bus and the PAMUX high-speed distributed I/O subsystem, enabling centralized control of remote multi-node I/O by the VME host. This module is specifically designed for long-distance and high-density distributed I/O scenarios. A single card can be expanded to 512 I/O points and is suitable for industrial automation, process control, semiconductor equipment, and large-scale measurement and control systems. Core positioning

As the core VME bus interface of the PAMUX system, XVME-202 assumes the dual roles of "bus protocol conversion + remote I/O scheduling", enabling the extension of VME system control capabilities to the farthest 150 meters (500 feet) of field nodes. This solves the pain points of complex centralized I/O wiring and limited distance in traditional systems. This series focuses on distributed I/O control and has no direct functional equivalent models. It is the only VME bus adapter module for the PAMUX system.

II. Core Function Characteristics

1. Standard VMEbus interface (fully compatible design)

Fully complies with IEEE 1014 VMEbus 2.0/3.0 specifications, compatible with all 3U VME enclosures and backplanes, and operates as a VME slave device. The address space adopts A16 (64KB), fixedly occupying a 1KB address range, the base address can be flexibly configured within the 1KB boundary through module jumpers to avoid system address conflicts. Data width supports D16/D08 (EO), compatible with 8/16-bit data transmission, and compatible with different bit-width VME master controllers. It has VME interrupt capability, supporting IRQ1–IRQ7 interrupt lines, interrupt vectors and priorities can be programmed, capable of responding to remote I/O status changes, fault alarms and other events of the PAMUX subsystem, achieving real-time interaction. The backplane connection only requires P1 connector, without the need for P2 auxiliary interface, simplifying the wiring and adaptation difficulty of the enclosure.

2. PAMUX Distributed I/O System Bridge (core function)

Directly compatible with the XYCOM PAMUX high-speed distributed I/O subsystem. Through a single 50-core flat ribbon cable, connect remote PAMUX intelligent nodes (Brain Boards) to achieve data interaction and control command forwarding between the VME host and remote I/O. A single module can address up to 16 PAMUX units (stations), each PAMUX station supports 32 independent I/O points, a single card can manage up to 512 I/Os, covering the control requirements of large-scale decentralized nodes. PAMUX nodes support daisy chain connection, can flexibly expand different functional sub-modules such as digital I/O, analog input/output, etc., adapting to mixed signal measurement and control scenarios. The remote communication distance can reach up to 150 meters (500 feet), without the need for relay equipment, meeting the long-distance wiring requirements of large factories, assembly lines, outdoor equipment, etc.

3. High-speed Data Transmission and Real-time Control

Using the PAMUX dedicated high-speed communication protocol, the 50-core ribbon cable supports bidirectional parallel data transmission, with fast instruction response speed, ensuring the real-time nature of remote I/O status collection and control command transmission, compatible with high-speed production lines, motion control, etc., which are sensitive to timing. It has built-in hardware data buffering and verification mechanisms, automatically verifying the integrity of transmitted data, reducing data errors caused by electromagnetic interference in industrial sites, improving the stability of remote communication. Supports dual modes of I/O point status polling and event trigger reporting, can actively collect the status of all nodes at regular intervals, or trigger reporting only when I/O status changes or faults occur, reducing the bandwidth occupation of the VME bus.

4. Industrial-grade High Reliability Design

Adopts a wide-temperature design, with a standard working temperature range of 0℃ to +70℃, and a storage temperature range of -40℃ to +85℃, compatible with industrial sites, outdoor equipment, etc., in harsh environments. The anti-vibration and anti-shock capabilities comply with industrial standards and can withstand 1g (10–100Hz) vibration and 15g shock, adapting to the vibration scenarios during equipment operation to prevent module loosening or communication failures. The EMC performance is compliant and has passed CE/FCC Class A certification. The circuit board adopts gold-plated finger contacts and shielding design to reduce electromagnetic interference and enhance the long-term stability of the system. The power consumption is low, with a typical working power consumption of +5V@1.2A (approximately 6W). The heat generation is small, and no additional heat dissipation module is required. It is suitable for enclosed chassis environments.

5. Panel status indicator lights and self-diagnosis

The front cover is equipped with multiple sets of status indicator lights, which visually display the module operation and communication status: the POWER indicator light, which is constantly on when the power is normal, and goes off when the power is off or the voltage is abnormal; the RUN indicator light, which is constantly on when the module is powered on and self-tested passes and is running normally, and goes off or flashes when there is a fault; the PAMUX ACT indicator light, which flashes when communicating with the remote PAMUX node, and goes off or is off when there is no communication; the INT indicator light, which flashes when triggered by a VME interrupt, and goes off when there is no interrupt. The built-in power-on self-diagnosis function automatically detects the module hardware, VME bus interface, and PAMUX communication link status upon power-on. Abnormalities are indicated by the flashing frequency of the indicator lights, simplifying the fault troubleshooting process.

III. Hardware Specifications Details

Bus-related Specifications

The bus protocol is IEEE 1014 VMEbus 2.0/3.0, in slave device mode; address space A16 (64KB), fixedly occupying 1KB, with base address jumpers configured; data width D16/D08 (EO); interrupt support IRQ1–IRQ7, programmable vector and priority; the backplane interface is only the P1 connector.

PAMUX Communication Specifications

The system is compatible with the XYCOM PAMUX distributed I/O subsystem; the connection cable is a 50-core flat ribbon cable; the maximum number of connected PAMUX stations is 16; the number of I/O points per station is 32; the maximum controlled I/O points are 512; the maximum communication distance is 150 meters (500 feet); the communication mode is bidirectional parallel transmission, supporting polling/event triggering.

Electrical and Environmental Specifications

Power supply +5V DC ±5%, typical current 1.2A; operating temperature 0℃～+70℃; storage temperature -40℃～+85℃; anti-vibration 1g (10–100Hz); anti-shock 15g; size 3U (100mm×160mm), single slot; weight approximately 0.4kg.

IV. Typical Application Scenarios

1. Large-scale industrial automation production lines

Suitable for long-distance assembly lines in industries such as automotive manufacturing, electronic assembly, and food processing, where PAMUX nodes are deployed at each workstation, and XVME-202 centrally controls the signals of sensors (proximity switches, photoelectric switches) and actuators (electromagnetic valves, motors), reducing the number of centralized I/O cabinets and simplifying wiring.

2. Distributed measurement and control in process industries

Compatible with industries such as power, chemical engineering, and water treatment. On-site instruments, valves, pumps, etc., are distributed, and XVME-202 uses the PAMUX system to achieve remote I/O data collection and control command issuance, meeting the requirements for long-distance and multi-node monitoring.

3. Semiconductor and precision equipment control

Used for semiconductor wafer processing and detection equipment. The multi-station and multi-axis motion control nodes inside the equipment are scattered, and XVME-202's high-density I/O expansion capability can cover all nodes, while high-speed communication ensures precise timing for motion control and signal acquisition. 4. Distributed Upgrade of Old VME Systems

The traditional VME systems are mostly centralized I/O systems, which have complex wiring and are difficult to maintain. The XVME-202 can be directly inserted into the existing VME chassis without modifying the host hardware and programs. It can upgrade the system to a distributed I/O architecture, extending the service life of old equipment and reducing the upgrade cost.

5. Large Measurement and Control Systems and Data Acquisition Systems

It is suitable for large measurement and control systems in aerospace, military, and research fields. The test points are scattered and the number of I/O is large. The XVME-202 can remotely expand 512 I/Os to achieve synchronous data acquisition and control of multiple nodes, meeting the requirements of complex testing scenarios.

VII. Installation and Programming Key Points Installation steps

Preparations: Ensure that the P1 slot of the VME chassis is intact, the +5V power supply is stable, and there is no short circuit or abnormal voltage; Prepare a 50-pin flat ribbon cable, check the pin definitions of the cable to avoid incorrect connections.

Jumper configuration: According to the system address planning, set the module base address jumper; Configure the interrupt vectors and interrupt priorities as needed to ensure compatibility with the system interrupt management.

Module insertion: Align the XVME-202 with the 3U slot, push it in smoothly, ensure that the gold fingers are in good contact with the backplane, tighten the panel fixing screws to prevent loosening.

Communication wiring: Connect one end of the 50-pin flat ribbon cable to the PAMUX interface on the front panel of the module, and the other end to the first PAMUX node. Connect subsequent nodes in a daisy chain manner to ensure firm wiring and no loose connections.

Power-on self-test: After the chassis is powered on, observe the panel indicator lights. POWER should be constantly on, RUN should be on, and PAMUX ACT should not flash (for unconnected nodes) or flash regularly (for connected nodes), indicating that the module self-test is successful and the system is running normally.

Programming process (simplified)

Address mapping: Configure the A16 base address in the system, map the internal registers of the module to the system memory space, and establish the communication channel between the VME host and XVME-202.

PAMUX node configuration: Configure the PAMUX node address, I/O type (digital / analog), and communication mode (polling / event-triggered) through the module control register.

Data acquisition: Read the input registers of the module to obtain the I/O status data of all PAMUX nodes, upload it to the system for processing, display, or storage.

Control output: Write control data to the module output register, and send it to the designated remote node through the PAMUX system to control the actuator action.

Interrupt configuration: Enable the required interrupt sources (I/O status changes, communication failures), write interrupt service programs, respond to remote events in real time, and perform emergency handling or status updates.

Six. Core advantages

1. High-density remote I/O expansion

A single card supports 512 I/O channels, covering large-scale distributed nodes, without the need for additional expansion modules. A single slot can achieve centralized remote I/O control, reducing chassis occupation and hardware costs.

2. Long-distance stable communication

Supports 150-meter transmission without repeaters, suitable for long-distance wiring scenarios in large factories, assembly lines, etc. Hardware verification and anti-interference design ensure stable data transmission, reducing interference from the site.

3. Flexible distributed architecture

PAMUX nodes are connected in a daisy chain, and digital / analog I/O sub-modules can be expanded as needed. It is suitable for mixed-signal, multi-type measurement and control scenarios. The architecture is flexible and has strong scalability.

4. Industrial-grade reliability, suitable for harsh environments

Wide temperature, vibration, and interference resistance design, gold-plated gold fingers and shielding process. Suitable for industrial sites, outdoors, military, etc., stable long-term operation, low maintenance costs.

5. Strong compatibility, easy integration and upgrade

Standard VMEbus interface, directly compatible with existing VME systems, without modifying the host hardware and program, can achieve distributed I/O upgrade, low replacement cost, and meets the maintenance requirements of outdated systems.

Seven. Precautions

The module is no longer in production. When purchasing, prefer to choose second-hand or refurbished spare parts with complete test reports. Check the model (common order number 70202-001) and version to avoid purchasing faulty or incompatible modules.

Only compatible with the XYCOM PAMUX dedicated I/O subsystem. It cannot be directly connected to other brand distributed I/O devices. When replacing or expanding nodes, confirm compatibility. The 50-core flat ribbon cable is a dedicated communication cable and requires the use of shielded cables to avoid being laid in the same trough as power cables, thereby reducing electromagnetic interference and ensuring stable communication.

Operating temperature: 0℃ to +70℃. During installation, it is necessary to ensure good ventilation of the chassis to avoid heat accumulation around the module. In high-temperature environments, it is recommended to reduce the communication load to extend the service life.

During installation and maintenance, proper static protection must be carried out. Wear anti-static wristbands and operate on an anti-static workbench to avoid static breakdown of the chips, which could cause module damage.