I am wanting to track DOWNTIME from our PLC’s. I will have 6-8 PLC’s that trigger alarms using SQLtags. So i will have an active_time and clear_time. I can do a simple query to tell me how long each alarm lasted, but this does not ultimately help me on TOTAL downtime.
As you can imagine, we might have multiple alarms CURRENTLY active at the same moment in time, but the active_time and clear_time could be different.
So, here is my ultimate question:
Say Alarm1 becomes active at 12:00:00 and clears at 12:05:30
Alarm2 becomes active at 12:02:30 and clears at 12:00:06
and Alarm3 becomes active at 12:03:00 and clears at 12:04:00
How could I determine ELAPSED time from the EARLIEST active to the LATEST clear?
I would also be totalling downtime by shift(12hrs), day, week, month and year.
So in conclusion, I need to GRAPHICALLY represent this on a chart with a timeline, which is why i chose the Gannt chart, and ALSO show the total downtime (based on filtering).