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DeltaV 13.3.1 mixed operating system inquiry
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LSNB Inquiry

The following observations were logged by our customer, during an FAT which require clarifications, that require detail knowledge of the DeltaV product.

Observation 1: SD to SZ Communication Delay

Both the primary and secondary ACN cables were disconnected followed by reconnection after a suitable Delay. Please can you explain why the delays?

It was observed that the Non-Secure parameter was delayed between and 30 seconds and 1 minute to cascade to CSLS and update following reconnection.

Also both Primary ACN between SZ and SD controllers was disconnected causing communications to be via the secondary ACN, it was observed that if one of the two Secondary ACN Link is disconnected a bad status is generated on the non-secure parameter. Note that one connection remain connected. It was also observed that if both secondary ACN is disconnected and one primary is also disconnected bad status is NOT generated on the non-secure parameter. Please can explain why bad status was generated?

Observation 2: LSN to GSN Communications Failure

When network cables between LSN and GSN is disconnected multiple evet messages were generated that were quite confusing, customer wishes to identify the most critical message that could be used to alert the operator, please can you confirm which message should be used?

Observation 3: Communication Between LSNBs

Our test system includes a setup of two LSNBs, but the target system will have several LSNBs, it was observed during testing that a failure between one LSNB and GSN, both LSNB generates an error message, customer is concerned that for a system with several LSNB if each LSNB generates an error message for a single failure then fault finding would be difficult, please can you explain how the message are being generated and do we expect a message from every LSNB in the system for a single failure?

Observation 4: LSNB Communication Delay

It was observed that there is a 7 seconds delay before a communications failure event is generated following  link disconnection to the LSNB, customer believes this could lead to SOE being misleading when diagnosing a shutdown event, please can you explain why the delay?


Jed Gonzales

2 Replies

  • Andre Dicaire
    I suggest you call the GSC to get to the bottom of these questions. Especially if time is of the essence to get answers.

    I would like to point out that disconnecting both networks at the same time simulates a highly unlikely failure mode, and is considered two separate failures occurring at the same time. Product design for availability is intended to prevent single point failures from negatively impacting the system. It is good to understand these "what if" scenarios as they could be induced during maintenance or fault correction, but you should clearly position loss of both networks is not within the scope of maintaining system availability.

    I think 30 to 60 seconds to recover is long. However, to understand where the delays are, we would have to break down the various component communications, including how the delays is observed. The GSC would have resources to replicate and investigate for any product issues. I have too many questions about your setup before I'd begin to try and explain this end results.

    Andre Dicaire

  • Jed Gonzales
    Thank you Andrei.


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