Define the Required Time Architecture
The confirmed requirement is to use a VXI IRIG card as the common time reference for instrumentation and one or more Windows PCs. The card manufacturer does not provide an NTP interface, so the missing component is a custom bridge that reads the IRIG-derived time and serves it to the PCs through NTP.
| Item | Evidence status | Engineering decision |
|---|---|---|
| Time reference | VXI IRIG card | Use the card's decoded time as the server reference. |
| PC interface | NTP required | Implement an NTP service that exposes the IRIG-derived time. |
| Card software interface | Not specified | Identify the existing command, driver, or block that returns time. |
| Manufacturer NTP support | Unavailable | Develop and maintain the bridge independently. |
Resolve the Missing Interface Details
Before writing the server, determine exactly how host software reads time from the card. The evidence does not identify a VISA, IVI, serial, or other programming interface, so do not select one by assumption. Inspect the installed card documentation and driver capabilities for an existing time-read operation.
Also define whether the application must only answer NTP requests or must discipline the Windows system clock. These are different implementation scopes. Record the card time representation, update behavior, validity indication, and error reporting before mapping its output into the NTP service.
Implement and Verify the Custom Bridge
- Read the decoded IRIG time through the card's documented software interface.
- Reject or flag readings when the card reports that its time is invalid; the evidence does not specify the available validity mechanism, so confirm it from the card interface.
- Expose the accepted reading through the custom NTP server to the required Windows PCs.
- Configure each PC to query that server, then verify that the PCs and instrumentation reference the same IRIG source.
- Test loss and restoration of the IRIG input. Confirm that the service does not present an unverified timestamp as valid and that normal service resumes only after the card again reports usable time.
Verification must compare the card-reported time, the time returned by the NTP service, and the time observed by each client. Set acceptance limits from the instrumentation application's synchronization requirement because the evidence provides no accuracy, latency, or update-rate values.
FAQ
Can a VXI IRIG card serve NTP directly?
Not in the described installation. The manufacturer stated that no NTP interface is provided, so a custom software bridge is required.
What interface should read time from the VXI IRIG card?
The available evidence does not identify the interface. Use the card's documented command, driver, or block that returns decoded IRIG time rather than assuming VISA, IVI, or serial access.
How do I verify an IRIG-to-NTP server?
Compare the card-reported time with the NTP response and each Windows client's observed time. Also remove and restore the IRIG input to verify that invalid time is detected and not served as verified time.