# How to create a report when a process of unknown duration finishes?

**URL:** <https://forum.inductiveautomation.com/t/how-to-create-a-report-when-a-process-of-unknown-duration-finishes/116677>\
**Category:** Ignition\
**Tags:** reporting\
**Created:** [August 5, 2026, 7:50pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-report-when-a-process-of-unknown-duration-finishes/116677 "2026-08-05T19:50:53Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![dfox37](https://avatars.discourse-cdn.com/v4/letter/d/bc79bd/32.png) [@dfox37](https://forum.inductiveautomation.com/u/dfox37)\
**Post date:** [August 5, 2026, 7:50pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-report-when-a-process-of-unknown-duration-finishes/116677/1 "2026-08-05T19:50:53Z")

</div>

This is a two-part question, one on triggering a report and the other on how to grab just the data I need. I've been asked to setup a historical trend on a report that starts when the process starts and ends when the process ends. I then need to trigger it to print or save when the process ends. I could use some help figuring out how to trigger the report when the process ends. I have a simple bit in the PLC that's high when the process is running and low when the process isn't running. I see I can also use this bit to trigger a transaction group to start and stop, my only problem is then how do I query just that timeframe of data? I've triggered that bit several times and all I have is one big table with jumps in the date range (t\_stamp), and I could also add this bit as a pointer in the data but again it's just one big table. Let's say the process ran yesterday am, then yesterday pm, then today am, all at random times. How would I print a report of just today's data if the start times and end times are completely variable? Is this even possible? I know by hand I could do it by just manipulating a historical trend and then printing it out when I'm done but is there a way to automate this. Any help would be great.

---

<div class="post-metadata">

**Author:** ![Chris\_Bingham](https://avatars.discourse-cdn.com/v4/letter/c/e5b9ba/32.png) [@Chris\_Bingham](https://forum.inductiveautomation.com/u/Chris_Bingham)\
**Post date:** [August 5, 2026, 8:04pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-report-when-a-process-of-unknown-duration-finishes/116677/2 "2026-08-05T20:04:18Z")

</div>

Can you create a ring buffer in the PLC which stores relevant data for the last ## processes? Include start time, end time, and any other summaries for that 'batch'. You can then read the most-recent index to generate a report for the most-recent process (or read entire array to generate reports / summaries for last ## processes).

---

<div class="post-metadata">

**Author:** ![lane.duncan](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lane.duncan/32/83700_2.png) [@lane.duncan](https://forum.inductiveautomation.com/u/lane.duncan)\
**Post date:** [August 6, 2026, 6:41am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-report-when-a-process-of-unknown-duration-finishes/116677/3 "2026-08-06T06:41:46Z")

</div>

I would assign each production run a unique identifier (production\_id) and record this value along with a start time and end time in a separate database table.

Then query this table to fill in the start time and end time of your report parameters.