XYCOM XVME-976 Retrofit Power Supply for Legacy VME Systems

XYCOM XVME-976 Retrofit-Compatible Power Supply for Legacy VME Systems

The XYCOM XVME-976 is a ruggedized VMEbus power supply module engineered for continuous operation in harsh industrial environments. Designed to deliver stable, regulated DC power across a full VME backplane, the XVME-976 is a proven solution for facilities managing aging XYCOM-based control architectures that cannot afford unplanned downtime or costly full-system replacements. As original XYCOM production lines have been discontinued, sourcing a verified, tested replacement has become a critical priority for maintenance engineers across process control, defense electronics, and industrial automation sectors.

NINERMAS maintains ready stock of the XVME-976 and compatible XYCOM VMEbus modules, each subject to pre-shipment functional testing and backed by a 12-month warranty. Our supply chain is specifically structured to support long-term spare parts programs for legacy VME platforms, ensuring your retrofit or emergency replacement project is not delayed by procurement lead times.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

Replacing a VMEbus power supply in an operational control system requires careful pre-work to avoid cascading failures across the backplane. Before removing the existing XVME-976 or its equivalent, engineers should document the current power rail voltages under load using a calibrated multimeter, and confirm that all installed VME modules — including CPU boards such as the XYCOM XVME-688 or XVME-540, I/O modules like the XVME-240 digital I/O board, and communication modules such as the XVME-490 — are within the power budget of the replacement unit.

In systems where the XYCOM VME chassis is integrated with a broader DCS or SCADA architecture, the power supply replacement must be coordinated with the control room operator. If the chassis hosts a real-time controller running time-critical process loops — for example, interfacing with Emerson PROVOX or Foxboro I/A Series field devices via serial or Ethernet bridges — a controlled shutdown sequence must be followed to prevent process upsets. Operators should place affected loops in manual mode and confirm that downstream actuators are in a safe state before de-energizing the chassis.

For systems using the XYCOM XVME-500 series single-board computers or XVME-566 Pentium CPU modules, the BIOS and application software reside on onboard flash or a local hard disk. These do not require re-programming after a power supply swap, but it is good practice to verify the boot sequence and confirm that all I/O modules re-initialize correctly after power restoration. If the system includes an XVME-230 analog I/O module or XVME-566 with onboard memory, confirm that battery-backed RAM has retained its configuration data.

Where the VME chassis is housed in a control cabinet alongside other equipment — such as a Siemens SIMATIC S5 or S7 PLC rack, Allen-Bradley SLC 500 I/O modules, or a dedicated signal conditioning rail with Phoenix Contact or Weidmüller terminal blocks — the physical installation space must be confirmed before ordering. Measure the available slot width, card guide spacing, and front-panel clearance. Confirm that the replacement XVME-976 can be inserted and extracted without disturbing adjacent modules or cable harnesses.

Communication links that pass through the VME chassis — including RS-232, RS-485, or MIL-STD-1553 interfaces hosted on co-resident communication modules — should be documented and tested after the power supply is restored. If the system uses a VMEbus-to-Ethernet bridge or a dedicated protocol converter for Modbus RTU or PROFIBUS DP, verify that these links re-establish automatically and that no manual re-initialization of the communication stack is required.

Downtime Control During System Migration

Minimizing downtime during a VMEbus power supply replacement is achievable with disciplined pre-planning. The most effective approach is to pre-stage the replacement XVME-976 unit in the workshop, perform a bench power-on test to confirm all output rails are within specification, and have all tools and documentation ready before the maintenance window begins.

Where a hot-standby chassis is available, the preferred strategy is to transfer control to the redundant system before beginning work on the primary chassis. In single-chassis installations without redundancy, the maintenance window should be scheduled during a planned production shutdown or low-demand period. Coordinate with operations to confirm that all process loops are in manual or safe-state before de-energizing.

During the swap, label all cable connections to the front panel of the outgoing module before disconnection. Photograph the wiring arrangement if the chassis has been modified from its original factory configuration. After installing the replacement XVME-976, restore power incrementally if the chassis design permits, and monitor each power rail with a multimeter before allowing the CPU and I/O modules to initialize. Confirm that the system returns to normal operation — including all communication links, I/O scan cycles, and HMI display updates — before releasing the process back to automatic control.

NINERMAS ships all XVME-976 units with a pre-shipment test report. This documentation confirms that the unit has been powered on, output voltages verified under load, and any fault indicators checked prior to dispatch. This reduces the risk of receiving a non-functional unit and shortens the on-site commissioning time. All units are covered by a 12-month warranty from the date of shipment.

Retrofit Support FAQ

Q1: Is the NINERMAS XVME-976 a direct drop-in replacement for the original XYCOM unit?
Yes. The XVME-976 supplied by NINERMAS is form-fit-function compatible with the original XYCOM XVME-976. It uses the same VMEbus 6U form factor, the same P1/P2 connector configuration, and delivers the same regulated DC output rails. No chassis modification or backplane re-wiring is required for a standard replacement. Customers are advised to confirm the AC input voltage range on the unit label matches their site supply before installation.

Q2: What pre-shipment testing does NINERMAS perform on the XVME-976?
Every XVME-976 unit is powered on in our test facility, output voltages are measured under representative load conditions, and all status LEDs and fault indicators are verified. A test report is included with each shipment. Units that do not meet specification are quarantined and not dispatched. This process is designed to eliminate the risk of receiving a dead-on-arrival unit in a time-critical maintenance situation.

Q3: Can the XVME-976 be used in a chassis that also houses newer VME64 or VME64x modules?
The XVME-976 is designed to the VMEbus (IEEE 1014) standard and is electrically compatible with VME64 backplanes. However, VME64x systems with 2eSST or 2eVME high-speed transfers may have additional power requirements. Customers integrating the XVME-976 into a mixed-generation chassis should perform a full power budget calculation across all installed modules before commissioning. NINERMAS technical support can assist with compatibility assessment on request.

Q4: What is the warranty coverage and what does it include?
All XVME-976 units supplied by NINERMAS are covered by a 12-month warranty from the date of shipment. The warranty covers manufacturing defects and functional failures under normal operating conditions. It does not cover damage caused by incorrect installation, overvoltage events, or physical mishandling. In the event of a warranty claim, NINERMAS will arrange for unit return, inspection, and replacement or repair at no additional charge to the customer. Contact sale@ninermas.com to initiate a warranty claim.