Counting hours

Forum|Forum|6 years ago
March 5, 2020
2 replies
3238 views

hi community,

I want to calculate the sum of time during a variable is equal to true , we can simulate this by a lamp and we want to calculate how many hours that lamp is on;

thanks in advance

Coding

P

PaiChung

22-Sapphire I

You can use the On DataChange event.

When a data change happens, the subscription receives Old and New VTQ (Value Time Quality)

this allows you to determine what state the lamp changed into and what the time delta was.

(Make sure to set the DataChange to Value so you aren't capturing unnecessary triggers)

A

anassNasser

Author

1-Visitor

Thank you @PaiChung ;

I don't know how to use eventData.newValue.time; or eventData.oldValue.time, to calculate delta between the start and the end.

I need more detail please,

thank you

P

PaiChung

22-Sapphire I

If you look in the snippets there is a date functions library which has dateadd available.

the result returned will be milliseconds.

R

rjanardan

16-Pearl

I am assuming your data would look something like ON, Timestamp and OFF, Timestamp. If you are storing it in a value stream and using InfluxDB as persistent provider then an approach would be to use InfluxDB API /query HTTP endpoint through a service and use its ELAPSED function(calculates the difference between subsequent timestamps) and sum it, to obtain the total uptime between a specified interval. Please note that, I have not tested this approach.