XYCOM XVME-686 – 6U VMEbus Pentium‑class SBC for stable industrial control and legacy system life extension

The XYCOM XVME-686 is a 6U VMEbus single board computer typically built around a “686-class” x86 processor (Pentium/Pentium MMX generation). It’s the kind of board you use when you need reliable Windows/OS‑9/RT‑Linux performance inside an existing VME rack without redesigning the whole control cabinet. From my experience, it’s a practical fit for test stands, semiconductor tools, and process control lines that still depend on VME timing and interrupt behavior but need PC‑compatible compute.

You might notice that different sub‑revisions exist—some units present IDE storage only, others include SCSI or additional serial ports. That’s pretty normal for Xycom’s VME SBCs of this era. If you’re matching a fielded system, we usually confirm the exact front‑panel I/O and BIOS rev before shipping. One thing I appreciate is how these boards tend to “just slot in” electrically: +5 V from the backplane, standard 6U mechanics, and familiar VME A24/A32 addressing support.

Our Order Process and Guarantees

• Warranty: 365 days
• Lead time: 1 week if in stock; no more than 1 month latest
• Payment: 50% advance; full balance prior to delivery
• Express shipping: FedEx, UPS, DHL
• Pre‑ship testing: basic power‑on and interface checks, anti‑static packaging

Key Features

• 686‑class x86 CPU – Typically Pentium/Pentium MMX performance for deterministic control and HMI tasks.
• 6U VME form factor – Standard Eurocard mechanics; installs into existing 6U VME card guides and backplanes.
• VMEbus A24/A32, D16/D32 – Master/slave support in most configurations; integrates with legacy VME I/O and interrupt schemes.
• On‑board PC‑style I/O – Commonly includes dual serial ports (RS‑232), parallel LPT, VGA, IDE; some variants add 10/100 Ethernet and/or SCSI.
• Boot flexibility – Diskless boot, IDE flash, or HDD depending on revision; useful for systems with limited service access.
• Industrial operating range – Designed for cabinet environments with forced‑air cooling; typical 0–50 °C operation.
• Field‑proven reliability – Many users run these 24/7; we regularly see stable uptimes in test rigs and packaging lines.

Technical Specifications

Related or Supporting Products

• XYCOM XVME-652 Digital I/O Module – Pairs well as a high‑density DI/DO card for machine signals; XVME‑686 handles the application and networking.
• XYCOM XVME-566 Analog Input Module – For process monitoring (temperature, pressure, flow) when you need precise A/D under the same VME chassis.
• XYCOM XVME-690 Series Output – Used in many retrofits for relay/analog output; complements the SBC for closed‑loop control.
• Modern VME SBC alternatives (Pentium‑M/Core era) – If you need more CPU and native Gigabit Ethernet, we can suggest new‑build VME SBCs with OS image migration support.

Installation & Maintenance

• Cabinet & airflow – Use standard 6U VME card guides; ensure forced‑air cooling across the CPU heat sink. In most cases, 1–2 m/s airflow keeps temps in spec.
• Power budget – Verify the +5 V rail headroom on the backplane. Add margin if running a spinning HDD or high‑draw graphics.
• Wiring & I/O – Secure front‑panel connectors and use strain relief. If a rear transition module is used, confirm pinout per the specific XVME‑686 revision.
• OS & storage – For legacy OS images, we typically recommend IDE CF or DOM to reduce vibration issues versus HDDs.
• Routine maintenance – Quarterly dust cleaning, check fan filters, reseat edge connectors annually, and replace the CMOS battery proactively every 3–5 years.
• Firmware – Keep a copy of the exact BIOS/firmware. Where available, apply only tested updates; some older applications are sensitive to BIOS changes.
• ESD & safety – Handle with ESD protection; remove power before insertion/removal; follow VME hot‑swap policy of your chassis (most are not hot‑swap).

Quality & Certifications

• Manufacturer quality systems: typically ISO 9001 at time of production
• CE marking on most original releases; UL recognition where applicable
• RoHS: many XVME‑686 units pre‑date RoHS; non‑RoHS units are common in legacy support
• Warranty from us: 365 days, with advance replacement support when stock allows