# How to Create a Sequence of Events view in Perspective

**URL:** <https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [September 23, 2024, 5:32am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293 "2024-09-23T05:32:39Z")\
**Posts on this page:** 17\
**Page:** 1

<div class="post-metadata">

**Author:** ![Aaron\_Stinson](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Aaron\_Stinson](https://forum.inductiveautomation.com/u/Aaron_Stinson)\
**Post date:** [September 23, 2024, 5:32am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/1 "2024-09-23T05:32:39Z")

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Is it possible to make a view that will display the most recently updated tags in order of when they were updated?

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [September 23, 2024, 6:29am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/2 "2024-09-23T06:29:52Z")

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Edit: _ **For changed configuration** _  
Yes. You'll need to have auditing turned on, and then you can just run a query on the audit log, filtering to `tag edit` actions.

E.g. (for MS SQL Server)

```python
SELECT TOP 100
	*
FROM
	AUDIT_EVENTS
WHERE
	ACTION = 'tag edit'
ORDER BY EVENT_TIMESTAMP DESC

```

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [September 23, 2024, 7:30am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/3 "2024-09-23T07:30:29Z")

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I think he meant updates of values, not edits.  
I guess you could use the historian and fetch the n last historized values ?

Depending on what tags you want to monitor (all of them ? Some specific subset ?), You could add a table in your database, and a "tag change" gateway event. Add the tags your want to monitor, and script an insert into the database. Prune regularly.  
Or use a memory dataset tag instead of a db table.

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [September 23, 2024, 7:45am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/4 "2024-09-23T07:45:15Z")

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Ah, that might make more sense. In that case, I don't know ~~the best~~ a good method...

> [@pascal.fragnoud](#):
>
> I guess you could use the historian and fetch the n last historized values ?

This wouldn't work for unhistorised tags

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<div class="post-metadata">

**Author:** ![victordcq](https://avatars.discourse-cdn.com/v4/letter/v/f6c823/32.png) [@victordcq](https://forum.inductiveautomation.com/u/victordcq)\
**Post date:** [September 23, 2024, 11:52am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/5 "2024-09-23T11:52:27Z")

</div>

There is a timestamp in the Qualified tag values... (Altho this value might reset if gateway restarts)  
With browse you could go over all of them. This works, but there is probably a more efficient method.  
(example readblocking them all at once)  
Im sure @pascal.fragnoud will improve this 🙂

```python
browsedTags = system.tag.browse(path = '[default]', filter = {})

def getTime(tagName):
  return system.tag.readBlocking(tagName)[0].getTimestamp()

sortedPaths = sorted([str(x['fullPath']) for x in browsedTags.getResults()], key=getTime, reverse=True)

```

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [September 23, 2024, 12:04pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/6 "2024-09-23T12:04:50Z")

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Keep in mind that the timestamps Ignition gets from an OPC UA server, or generates in its own drivers, is almost always the timestamp of the _ **poll** _, when the change was detected by OPC, not the actual timestamp when the signal changed in the real device. This means the ordering will be pseudo-random for signals that changed close in time, less than the poll interval.

If you really need sequence of events, you **must** timestamp **precisely** in the PLC and then buffer transfer to Ignition.

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [September 23, 2024, 12:08pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/7 "2024-09-23T12:08:22Z")

</div>

Here's how I'd write that:

```python
paths = [str(tag['fullPath']) for tag in system.tag.browse(path='[default]', filters={'recursive': True})]

sorted_tags = sorted(system.tag.readBlocking(paths), key=lambda qv: qv.timestamp, reverse=True)

```

Mainly to avoid reading tags individually, but I'd probably stick with a gateway event tag change script to maintain a list of the n most recent tags. I wouldn't want to have to browse a full tag provider, then sort all of them, just to get a few of them.

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<div class="post-metadata">

**Author:** ![victordcq](https://avatars.discourse-cdn.com/v4/letter/v/f6c823/32.png) [@victordcq](https://forum.inductiveautomation.com/u/victordcq)\
**Post date:** [September 23, 2024, 12:40pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/8 "2024-09-23T12:40:06Z")

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> [@pascal.fragnoud](#):
>
> `'full_Path']`

Pretty sure it was `fullPath`. Otherwise much better than mine 😛

And yeah i wouldnt really do this either, but you can filter some more on the browse i guess if its only a couple of tags you want to do

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [September 23, 2024, 12:51pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/9 "2024-09-23T12:51:43Z")

</div>

> [@victordcq](#):
>
> Pretty sure it was `fullPath`.

It is, I mistyped it.

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<div class="post-metadata">

**Author:** ![Aaron\_Stinson](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Aaron\_Stinson](https://forum.inductiveautomation.com/u/Aaron_Stinson)\
**Post date:** [September 24, 2024, 2:01am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/10 "2024-09-24T02:01:01Z")

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Hi all, Ive come up with a solution  
First ive created these global functions

This function creates a list of all tags in my project

```python
*def browse_tags_recursive(path):*
* # Browse the tags at the given path*
* results = system.tag.browse(path)*
* tag_list = []*

* for result in results.getResults():*
* # If the result is a folder, recurse into it*
* if result['hasChildren']:*
* sub_folder_tags = browse_tags_recursive(result['fullPath'])*
* tag_list.extend(sub_folder_tags)*
* else:*
* # If the result is a tag, add it to the list*
* tag_list.append(result['fullPath'])*
* *
* return tag_list*

```

this function sorts the dataset by date

```python
*def sort_dataset_by_column(dataset, column_index, ascending=True):*
* # Extract rows as lists*
* rows = []*
* for i in range(dataset.getRowCount()):*
* row = []*
* for j in range(dataset.getColumnCount()):*
* row.append(dataset.getValueAt(i, j))*
* rows.append(row)*
* *
* # Sort the rows based on the specified column index*
* sorted_rows = sorted(rows, key=lambda x: x[column_index], reverse=not ascending)*
* *
* # Rebuild the dataset with sorted rows*
* headers = [dataset.getColumnName(i) for i in range(dataset.getColumnCount())]*
* sorted_dataset = system.dataset.toDataSet(headers, sorted_rows)*
* *
* return sorted_dataset*

```

this funtion trims the historian data to only display changes

```python
*def filter_dataset_on_column_change(dataset, column_index):*
* # Initialize an empty list to store the filtered rows*
* filtered_rows = []*
* *
* # Get the value of the first row's specified column*
* previous_value = None*
* *
* # Iterate through the dataset rows*
* for i in range(dataset.getRowCount()):*
* current_value = dataset.getValueAt(i, column_index)*
* *
* # If the current value is different from the previous value, keep the row*
* if current_value != previous_value:*
* row = [dataset.getValueAt(i, col) for col in range(dataset.getColumnCount())]*
* filtered_rows.append(row)*
* *
* # Update the previous_value to the current value*
* previous_value = current_value*
* *
* # Rebuild the dataset with only the filtered rows*
* headers = [dataset.getColumnName(i) for i in range(dataset.getColumnCount())]*
* filtered_dataset = system.dataset.toDataSet(headers, filtered_rows)*
* *
* return filtered_dataset*

```

I then use this script attached to a refresh button to generate a dataset which i display in an table.

```python
*def runAction(self, event):*
*	# Start browsing from the root of the default provider*
*	all_tags = myFuncs.browse_tags_recursive('[default]')*

*	datasets=[]*
*	endTime = system.date.now()*
*	startTime = system.date.addMinutes(endTime, -30)*
*	#poll historian for each tags recent data*
*	for tag_path in all_tags:*
* data =system.tag.queryTagHistory(*
* paths=[tag_path],*
* returnFormat="Tall", *
* aggregationMode="MinMax",*
* returnSize=0,*
* startDate=startTime, *
* endDate=endTime*
* )*
* filtered_data = myFuncs.filter_dataset_on_column_change(data, 1)*
* if filtered_data.getRowCount()>0:*
* datasets.append(filtered_data)*
*	if datasets:*
* combined_dataset = datasets[0]*
* for ds in datasets[1:]:*
* combined_dataset = system.dataset.appendDataset(combined_dataset, ds)*
* *
*	# Example: Ordering the combined dataset by the 4th column (most recent date first)*
*	ordered_dataset = myFuncs.sort_dataset_by_column(combined_dataset, 3, ascending=False)*
*	self.view.custom.dataset=ordered_dataset*

```

This appears to work - ill be looking into making a similar function that does not use the tag historian

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<div class="post-metadata">

**Author:** ![Aaron\_Stinson](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Aaron\_Stinson](https://forum.inductiveautomation.com/u/Aaron_Stinson)\
**Post date:** [September 24, 2024, 2:39am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/11 "2024-09-24T02:39:03Z")

</div>

> [@pascal.fragnoud](#):
>
> ```python
> paths = [str(tag['fullPath']) for tag in system.tag.browse(path='[default]', filters={'recursive': True})]
> 
> sorted_tags = sorted(system.tag.readBlocking(paths), key=lambda qv: qv.timestamp, reverse=True)
> 
> ```

This works but wont display if a tag eg. Gate\_01\_state changes multiple times and will only show the most recent change

Is this avoidable?

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [September 24, 2024, 4:03am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/12 "2024-09-24T04:03:28Z")

</div>

> [@Aaron\_Stinson](#):
>
> ```python
> *def browse_tags_recursive(path):*
> * # Browse the tags at the given path*
> * results = system.tag.browse(path)*
> * tag_list = []*
> 
> * for result in results.getResults():*
> * # If the result is a folder, recurse into it*
> * if result['hasChildren']:*
> * sub_folder_tags = browse_tags_recursive(result['fullPath'])*
> * tag_list.extend(sub_folder_tags)*
> * else:*
> * # If the result is a tag, add it to the list*
> * tag_list.append(result['fullPath'])*
> * *
> * return tag_list*
> 
> ```

Don't do this, `system.tag.browse` has a `recursive` option within its `filter` arg for this. Recursive browsing manually is magnitudes slower.  
e.g.

```python
system.tag.browse(..., filter={'recursive': True, ...})

```

It looks like you can create a Gateway Tag Change script using a tag path with wildcards, so you could use this perhaps... no idea how this would scale...  
e.g.  
Tag paths: `[default]*`

If you're adding these changes into a dataset tag, you most certainly will need to manage this, otherwise you _absolutely_ will end up overwriting the dataset with missing added values if you simply try to read the dataset and write back to it with the inserted value. I would probably keep the data as a list of dicts in memory in a script library and write that into the dataset tag periodically.

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [September 24, 2024, 7:12am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/13 "2024-09-24T07:12:30Z")

</div>

No, not on its own. I wasn't suggesting you do this. My suggesting was, and still is, that you use a gateway event to monitor tag changes and maintain a dataset tag or the most recent changes.

It would look something like this

```python
history = system.tag.readBlocking(["path/to/dataset_tag"])[0].value

if history is None:
	history = system.dataset.toDataSet(['tag_path', 'value', 'timestamp'], [])

history = system.dataset.addRow(history, 0, [event.tagPath, newValue.value, newValue.timestamp])

if history.rowCount > MAX_ROWS:
	history = system.dataset.deleteRow(history, MAX_ROW_COUNT)

system.tag.writeBlocking(["path/to/dataset_tag"], [history])

```

Every time one of the monitored tag changes, it will add its path, value and timestamp at the top of the dataset, then if there are too many rows, remove the last one.

Haven't tried to run it, so there might be typos and such, but that's pretty much what I had in mind.

Now all you have to do is bind a table to that tag and you'll have the data you want.

Note that if your tags change very quickly, or if you have a LOT of tags, then I'd switch to a timer script that would run every 5 or 10 secs, pull the data from the dataset, make a tag browse, sort them by timestamp, then pop values from both the history dataset and the tags, taking the most recent one, to put it into a new dataset.  
something like

```python
tags_paths = [tag['fullPath'] for tag in system.tag.browse('', filters={'recursive': True})]
tags = system.tag.readBlocking([HISTORY_PATH] + tags_paths)
history = system.tag.toPyDataSet(tags[0].value)
tags = sorted(zip(tags[1:], tags_paths), key=lambda v: v[0].timestamp)

new_history = []
for i in xrange(MAX_NUM_OF_ROWS):
	if len(history) > 0 and len(tags) > 0 and history[0]['timestamp'] > tags[0][0].timestamp:
		new_history.append(history.pop(0))
	elif len(tags) > 0:
		tag = history.pop(0)
		new_history.append([tag[1], tag[0].value, tag[0].timestamp])

new_history = system.dataset.toDataSet(['tag_path', 'value', 'timestamp'], new_history)
system.tag.writeBlocking([HISTORY_PATH], [new_history])

```

Completely untested and absolutely optimizable (use queue types for starters), so treat this like pseudo code to get you started.

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [September 24, 2024, 8:28pm UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/14 "2024-09-24T20:28:59Z")

</div>

> [@pascal.fragnoud](#):
>
> It would look something like this
> 
> ```python
> history = system.tag.readBlocking(["path/to/dataset_tag"])[0].value
> 
> if history is None:
> history = system.dataset.toDataSet(['tag_path', 'value', 'timestamp'], [])
> 
> history = system.dataset.addRow(history, 0, [event.tagPath, newValue.value, newValue.timestamp])
> 
> if history.rowCount > MAX_ROWS:
> history = system.dataset.deleteRow(history, MAX_ROW_COUNT)
> 
> system.tag.writeBlocking(["path/to/dataset_tag"], [history])
> 
> ```
> 
> Every time one of the monitored tag changes

This won't work if multiple tags change at once _ **Edit: if these are in tag change events** _, as the dataset tag will be read for all potentially at the same time and then the new row will be added into the local variable, and then this will be written to the dataset tag for each change, but they will all overwrite each other in the process. Only the last to execute will actually make it into the dataset

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<div class="post-metadata">

**Author:** ![Aaron\_Stinson](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Aaron\_Stinson](https://forum.inductiveautomation.com/u/Aaron_Stinson)\
**Post date:** [September 25, 2024, 5:07am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/15 "2024-09-25T05:07:14Z")

</div>

Thanks

I used this in combination with a query to the alarm journal to produce a sequence of events that captures all tag changes and all alarm changes

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [September 25, 2024, 5:27am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/16 "2024-09-25T05:27:26Z")

</div>

Are you sure about that ? I thought gateway events were queued.

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [September 25, 2024, 9:12am UTC](https://forum.inductiveautomation.com/t/how-to-create-a-sequence-of-events-view-in-perspective/96293/17 "2024-09-25T09:12:49Z")

</div>

Ah, I think you're right. I had tag change scripts on the brain!