XYCOM XVME-400 Product Specification

1. Product Overview  

The XVME-400 is a 3U single-height VMEbus serial communication module developed by XYCOM (now part of Acromag/Xembedded), featuring four RS-232C serial channels. Designed specifically for industrial control and embedded systems, it enables multi-serial port expansion, data transmission, and device interconnection. Equipped with dual communication controllers and independent baud rate generators, the module is ideal for VME-based measurement and control applications, data acquisition systems, and upgrades to legacy systems. The product has been officially discontinued; currently available on the market are primarily used, refurbished, or surplus units. Its standard order number is 70400-001.

Core Features  

As a VMEbus slave device, the XVME-400 focuses on delivering "four independent RS-232C serial ports, synchronous/asynchronous communication, modem control, and interrupt-driven operation." With high-density integration in a single slot, it effectively addresses common limitations in VME systems—such as insufficient serial ports and limited communication modes—making it well-suited for industrial applications requiring multiple, highly reliable serial communication channels. 

II. Core Functional Features

1. Standard VMEbus Interface (Fully Compatible Design)  

Fully compliant with the IEEE 1014 VMEbus specification, compatible with all 3U VME chassis and backplanes, operating in slave mode. Supports A16 address space (64KB), with a fixed 1KB address window; base address is flexibly configured via onboard jumpers to avoid system address conflicts. Data width supports D08/D16, compatible with 8/16-bit VME master controllers. Backplane connection uses P1 connector, conforming to single-height module standards, supporting VME interrupts (configurable priority and vector), meeting requirements for real-time data transmission and fault alerts.

2. Four Independent RS-232C Serial Channels (Core Function)  

Equipped with two Zilog Z8530 serial communication controllers (SCCs), providing four fully independent RS-232C interfaces. Each channel features an independent baud rate generator, modem control signals, and interrupt capability, ensuring no interference between channels. Up to four serial devices (e.g., terminals, modems, PLCs, sensors) can be connected simultaneously.

Communication Modes: Supports asynchronous (ASCII), single synchronous, double synchronous, HDLC/SDLC protocols, accommodating both industrial standards and custom communication needs.  

Baud Rate Range: Asynchronous up to 57.6 kbps, synchronous up to 500 kbps; each channel independently programmable to match different device speeds.  

Modem Control: Each channel provides RTS, CTS, DCD, DTR hardware handshake signals, enabling standard modem connections and hardware flow control for stable data transmission.  

Electrical Characteristics: RS-232C levels (±12V), sufficient drive capability for standard serial devices, maximum transmission distance of 15 meters.

3. Flexible Interrupt and Data Transfer Control  

Supports multiple event interrupts, including transmit/receive completion, receive errors (parity/frame/overflow), and modem signal state changes. Individual channel interrupts can be masked, and interrupt vectors are configurable, suitable for high-real-time data transfer scenarios. Fast interrupt response, supporting DMA or polling-based data transfer, meeting diverse system architecture requirements.

4. Industrial-Grade High Reliability Design  

Standard operating temperature range: 0°C to +65°C; wide-temperature version covers -20°C to +70°C; storage temperature: -40°C to +85°C; humidity: 5%–95% RH (non-condensing). Designed for harsh environments such as industrial sites, outdoor installations, and test equipment. PCB features multi-layer routing and gold-plated edge connectors; critical circuits include noise suppression. Certified to CE/FCC Class A standards, offering strong ESD and electromagnetic interference resistance, ensuring long-term stable operation.

5. Panel Status Indicators  

Front panel includes POWER, RUN, and CH0–CH3 TX/RX LEDs: POWER stays on when +5V power supply is normal; RUN stays on when self-test passes and module operates normally; TX/RX blink during data transmission/reception on respective channels, facilitating quick field diagnosis of communication status.

III. Hardware Specifications Details

Bus Interface Specifications  

Bus Protocol: IEEE 1014 VMEbus, slave mode;  

Address Space: A16 (64KB), 1KB window, base address set by jumpers;  

Data Width: D08/D16;  

Interrupt Support: VME interrupt, configurable priority and vector;  

Backplane Connector: P1 connector;  

Dimensions: 3U (100mm × 233.4mm), single-slot; Weight: Approximately 0.3 kg.

Serial Channel Specifications  

Number of Channels: 4 independent RS-232C channels;  

Communication Controller: 2× Zilog Z8530 SCC;  

Communication Modes: Asynchronous, single synchronous, double synchronous, HDLC/SDLC;  

Baud Rate: Up to 57.6 kbps asynchronous, up to 500 kbps synchronous;  

Handshake Signals: RTS, CTS, DCD, DTR (per channel);  

Electrical Standard: RS-232C (±12V);  

Transmission Distance: Up to 15 meters;  

Connector: Front panel DB9 or DB25 interface (depending on version).

Electrical and Environmental Specifications  

Power Supply: +5V DC ±5%, typical current 1.1A, maximum 1.3A; +12V DC, typical current 100mA, maximum 110mA;  

Operating Temperature: 0°C to +65°C (standard), -20°C to +70°C (wide temperature);  

Storage Temperature: -40°C to +85°C;  

Vibration Resistance: 5–2000 Hz, 2.5g;  

Shock Resistance: 30g (operating) / 50g (non-operating);  

Humidity: 5%–95% RH (non-condensing);  

Altitude: Maximum operating altitude 3048 meters, maximum non-operating altitude 15240 meters.

IV. Typical Application Scenarios  

1. Serial Port Expansion for Industrial Control Systems  

Suitable for VME-based systems such as PLCs, DCS, and industrial computers, this module expands four RS-232C serial ports to connect operator terminals, printers, barcode scanners, serial sensors, and other devices, enabling data input/output and device interaction to meet multi-peripheral connectivity requirements.

2. Data Acquisition and Transmission Systems  

Used in industrial field data acquisition, it connects serial instruments, flow meters, temperature/humidity sensors, etc., collecting data via asynchronous/synchronous communication protocols and uploading to a VME host controller. Supports HDLC/SDLC protocols, ideal for long-distance, high-reliability data transmission scenarios.

3. Communication Upgrade for Legacy VME Systems  

Directly replaces outdated modules with insufficient serial ports or limited communication modes in legacy systems. No need to modify the chassis architecture or main program—upgrades the system with four RS-232C communication channels. Ideal for maintaining aging VME equipment in military, aerospace, and industrial control applications, extending equipment lifespan.

4. Interconnection in Embedded Systems and Devices  

Used in embedded measurement and control devices and intelligent instruments, enabling communication with external serial devices such as modems, serial servers, and other controllers. Supports hardware flow control and interrupt-driven operation, ensuring real-time and stable data transmission, suitable for industrial automation and test & measurement applications.

5. Building and Infrastructure Communication  

Applied in smart buildings, rail transit, and security systems, connecting serial access control units, alarm hosts, lighting control modules, etc., enabling inter-device data exchange and remote monitoring. Designed for wide temperature range and anti-interference performance, ensuring reliable communication in complex environments.

V. Installation and Programming Guidelines  

Installation Steps  

Preparation: Confirm that the VME chassis P1 slot is intact and that +5V/+12V power supply is stable. Prepare shielded RS-232C cables, clearly identifying TX/RX/GND lines.  

Jumper Configuration: Set the A16 base address jumpers to avoid address conflicts. Configure interrupt priority and vector jumpers if interrupts are required.  

Module Insertion: Align the XVME-400 with the 3U slot and insert smoothly, ensuring proper contact between the gold fingers and backplane. Tighten the front panel mounting screws.  

Wiring Connection: Connect serial devices to the front panel DB9/DB25 interface, linking TX to RX, RX to TX, and GND together. Shield the ground layer with single-ended grounding, and keep it away from strong interference sources such as inverters and motors.  

Power-on self-check: After power-up, the POWER and RUN indicators remain constantly lit, while all TX/RX indicators are off. When data is transmitted, the corresponding TX/RX indicator flashes, indicating normal module operation.

Programming Procedure (Simplified)  

Address Mapping: Configure the A16 base address to map control, data, status, and interrupt registers into system memory, establishing a communication channel between the CPU and the module.  

Channel Configuration: Write configuration words to the control register to set communication mode (asynchronous/synchronous), baud rate, data bits/checksum bits/stop bits, and flow control method.  

Data Transmission and Reception: Send or receive data via the data register, and read the status register to obtain channel status (transmit buffer empty, receive buffer full, error flags). Supports polling-based or interrupt-driven data transfer.  

Interrupt Configuration: Enable interrupts and set trigger conditions (data received, transmission complete, error), then write an interrupt service routine to handle real-time data and fault alerts.  

Reset Operation: During system or software reset, the module clears transmit/receive buffers, disables interrupts, and resets flags to ensure communication safety.

VI. Core Advantages  

1. Four Independent RS-232C Serial Ports with Strong Expansion Capability  

Integrates four fully independent serial ports in a single slot, each supporting independent baud rates and communication modes. No need for multiple modules, saving slot space and cost, meeting requirements for simultaneous connection of multiple devices.  

2. Multi-Protocol Communication with Broad Application Scenarios  

Supports asynchronous, synchronous, HDLC/SDLC, and other protocols, compatible with standard RS-232C devices. Can connect terminals, modems, PLCs, sensors, etc., suitable for industrial control, data acquisition, device networking, and more.  

3. Hardware Flow Control + Interrupt-Driven for Stable Real-Time Transmission  

Each port includes full modem handshake signals, enabling hardware flow control to prevent data loss. Multiple event interrupts support real-time data transmission and fault response, ensuring stable operation in high-real-time systems.  

4. Industrial-Grade Reliability with Robust Environmental Adaptability  

Designed for wide temperature range, vibration resistance, and anti-interference performance; compliant with EMC standards. Suitable for harsh environments including industrial sites, outdoor installations, and test equipment. Ensures long-term stable operation with low maintenance costs.  

5. Standard VME Bus for Easy Integration and Upgrades  

Fully compatible with VMEbus specifications, directly adaptable to existing 3U VME systems. Simple configuration and convenient wiring support both upgrades of legacy systems and new system deployment, offering excellent compatibility.

VII. Precautions  

This module has been discontinued. When purchasing, prioritize used or refurbished spare parts with complete test reports. Verify model number 70400-001 and version to avoid faulty or incompatible modules.  

Serial ports use RS-232C signal levels (±12V). Never connect RS-485/422 or high-voltage signals, which may damage the interface circuitry. For long-distance transmission, use shielded cables and limit distance to within 15 meters.  

Power supply must provide both +5V and +12V simultaneously to ensure voltage stability and prevent communication anomalies due to voltage fluctuations. Never reverse polarity to avoid damaging the module.  

Separate power lines for high and low voltage at site installation. Ground the shield layer unilaterally and keep the module away from strong interference sources to minimize electromagnetic interference affecting serial signals and prevent data transmission errors.  

Operating temperature range is 0°C to +65°C. Ensure proper ventilation around the chassis during installation to prevent heat buildup. In high-temperature environments, reduce baud rate to extend module lifespan.  

Take static protection measures during installation and maintenance—wear an anti-static wristband and work on an anti-static bench. Always disconnect the chassis power before inserting or removing the module to prevent damage to the backplane and module caused by live insertion/removal.