Maximum Required Delay Calculation

[BillP]

This question was originally posted by Joe on APC forums on 5/25/2017

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Research on how the MRD is calculated indicates that the NMC polls connected PCNSs.

What setting does the NMC key off of?

I have a basic test environment with an SU1500 (w/AP9630) and a Win 2008 Server (PCNS 4.2.0).  No matter what changes I make in the PCNS settings the MRD remains the same as the Low Battery Duration set on the NMC.

Not sure if this is related, but the "Force negotiation" radio button does not remain selected under PowerChute Shutdown Parameters.

Thanks >> Joe

[BillP]

This reply was originally posted by Bill on APC forums on 5/26/2017

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Hi,

The Maximum Required Delay is based on the greatest amount of time any registered PCNS client needs to complete the shutdown process. 

Example: there are 2 Windows server registered with AP9630 that is installed in SU model Smart-UPS. Each client is configured to start OS shutdown after the UPS has been on battery for 5 minutes. 1 of the clients is configured to run a command file prior to OS shutdown and that command file needs 4 minutes to complete it process.

When PCNS is restarted or when Force negotiation is selected and apply is clicked Maximum required delay is increased to 6 minutes Note: The changed can take up to 10 minutes when force negotiation is selected. 2 minutes for the default and 4 minutes for the command file delay. 

I recommend increasing the low battery threshold to be greater than the needed maximum required delay which will also increase the maximum required delay to match.

[BillP]

This reply was originally posted by Joe on APC forums on 5/27/2017

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Bill,

Thanks for the detailed answer.

We don't typically use Command Files but on more careful review it appears that is the only place where the PCNS can record a shutdown time requirement. We did try that setting but I thought the instructions indicated that the NMC should be rebooted.  I will go back and check.  We never tried restarting the PCNS.

Our Force Negotiation radio button does not stay selected when we hit apply. Is that normal?

[BillP]

This reply was originally posted by Bill on APC forums on 5/30/2017

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Hi,

On 5/26/2017 8:01 PM, Joe said:

Our Force Negotiation radio button does not stay selected when we hit apply. Is that normal?

Yes. The button reverts to unchecked after you click apply. 

[BillP · Accepted solution]

This reply was originally posted by Joe on APC forums on 5/30/2017

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Thanks