Maximum Required Delay negotiation not working with any predictability (Symmetra RM, AP9631, PCNS)

[ben_m]

I have 3 x Symmetra RM w/ AP9631 NMC (firmware v6.2.1)

I am trying to set up automatic shutdown and startup using PCNS 5.1.0

Although I have a redundant setup in production, right now I am testing with just one UPS and one PCNS host, not in redundant mode.  Everything communicates fine, the shutdown sequence sort of works (all the things that are supposed to happen, do happen), but the timing isn't right at all.

When On Battery occurs, I want to wait 3 minutes, run a script for 5 minutes, shut down the PCNS machine (allowing 30 seconds for that), shut down load power, then shut down the UPS.

UPS should remain shut down for 60 seconds minimum even if power has returned, remain shut down until input power is on and fuel >= 50%, and then come back up and turn the load on.

THE PROBLEM: When I "Force Negotiation", I expect Maximum Required Delay to indicate 6 minutes. because in PCNS "On Battery Event" I have a command script time of 600 and a Shutdown Delay of 30.  This is 5:30, rounded up to the nearest minute == 6.

This does not happen, the Maximum Required Delay remains stubbornly at 2 minutes.

However, I noticed that if I increase Low Battery Duration, it increases Maximum Required Delay to the same value, eg 12 Minutes == 12 Minutes.  But my understanding is that low battery duration is the amount of (calculated) runtime remaining before shutdown occurs, so I don't understand why these settings interact?

I don't want my shutdown based on the calculated runtime, but just straightforwardly shut down based on the time elapsed since power failed.  I have done runtime calibration, and I have around 30 minutes of runtime.. whereas I will only be on battery for 10 minutes before shutting down...

MY SETTINGS ARE BELOW

My Settings in PCNS "On Battery" Event:

Enable Command File: Checked, Delay: 300 (max seconds script requires to run), Path to Command File is correct and works...

Enable Shutdown: Checked, Delay: 30,

NMC Shutdown Config

Low Battery Duration: 02 Minutes (the minimum)

Shutdown Delay: 120 Seconds (but I expect the PCNS config to override this)

Maximum Required Delay: 2 Minutes (But I expected this to be negotiated to at least 6 minutes)

Basic Signalling Shutdown: Unchecked

Controlled Early Shutdown, Nothing checked right now, since I am expecting PCNS to do this.

Sleep Time: 0.0

Minimum Battery Capacity: 50%

Return Delay: 060 Seconds

Maximum Required Delay:  2 Minutes (I expect this to be at least 6)

On-Battery Shutdown Behavior: Restart when power is restored

I should mention that the shutdown DOES run, and the UPS shuts down.  But I can't set the timings to what I want.  If I muck about with the delay settings in PCNS I can cause the Maximum Required Delay to change in the NMC, but not in a way I can replicate or predict, some settings work, others do nothing...

Please help, thanks!  I have been working at this for quite a while....