Shutdown and Restart Events

[cwsturt3606]

I am hoping to develop a reporting tool for shutdown and start ups of units.

I am able to build capsules for RPM < 10 (unit down) and RPM >10 (unit running).

There is also a shutdown code that accompanies a shutdown (a number 1 - 54). The shutdown code does not latch, if the unit is left down the shutdown code eventually goes to zero.

 

My ultimate goal is to easily identify the shutdown event and code, duration of downtime (I already have this much) and date/time at startup. The hardest part is identifying when a unit goes from its operating speed to zero, and going from zero to operating speed.

 

[Siti Tay]

Hello,

Based on your question, there are 2 conditions that define your down time periods. 

1.  Speed RPM < 10 
   •  
2. Code = 0
   • 

Next, to identify period when the unit down ends to the starts of code down period, you can use composite condition (Join) which result in red condition below.

Then repeat the same composite condition to identify period when the  code down ends to the starts of unit down period, which result in yellow condition below.

• You can choose to include or exclude A or B condition if needed. 
• Adjust the maximum capsule duration depending on the gap between A to B condition. 

 

Let me know if this helps.

Edited July 20, 2023 by Siti Tay

[cwsturt3606]

I have tried join without success, and same as yours without "inclusive of A" nor "inclusive of B".

 

It also appears your RPM has a slope down. My data comes in and it appears the unit goes from 1100RPM to zero.

 

[Siti Tay]

I understand that the example didn't suit your case. Please try these two methods and see which one better suits your data.

Method 1 : 

1. Calculate the derivative for the speed data.

2. Apply value search when the derivative is not equal to 0 (you might need to adjust this value search criteria depending on your derivative signal).

This result in red conditions before and after the unit is down, with a duration of 0 seconds, as displayed in the capsule pane.

Method 2 :

Use beforeStart() and afterEnd() functions as shown below. You will need to specify the duration of the capsule, and in this example, the duration is 1 minute before and after the unit down. 

$before_down = $unit_down.beforeStart(1min)
$restart = $unit_down.afterEnd(1min)
$before_down.combineWith($restart)

 

Give these methods a try, and let me know if you encounter any issues or you can also join our Seeq Office Hours (https://info.seeq.com/office-hours) for further discussion. 

Edited July 24, 2023 by Siti Tay