Vijeo Citect Scada Trend Display

1. For how long period the trend shall be kept in history to be displayed on graph?
2. How to increase the trend graph history to be displayed for long time? for example, currently I could able to see the trend graph for past 3 days, but I would like to see for 10 days. How to change the settings?

Also, the history files gets deleted every three days. What could be the reason?

charzree said:

Also, the history files gets deleted every three days. What could be the reason?

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You just need to change the history settings on the trend tag, it's all detailed in the Citect help files (copy and paste below)

No. Files

The number of history files stored on your hard disk (for this tag) (4 characters maximum). The maximum number of files you can specify per trend tag is 999. Performance and storage will be severely impacted by having a large number of history files per trend.

By default, 2 history files are stored on your hard disk.

Period

The period of the history file, in hh:mm:ss (32 characters maximum). Alternatively, you can:
•Specify a weekly period by entering the day of the week on which to start the history file, for example Monday, Tuesday, Wednesday, etc.
•Specify a monthly period by entering the day of the month on which to start the history file, for example 1st, 2nd, 3rd, 4th, 5th, etc.
•Specify a yearly period by entering the day and the month on which to start the history file, for example 1st January, 25th February, etc. The day and month needs to be separated by a space.

If you do not specify a period, the period defaults to Sunday (weekly).

When deciding on a period setting, be aware that the performance of a trend viewer (be it the existing CitectSCADA or Process Analyst) may be impacted by the size of a trend file. This is particularly true when displaying event-based trend data.


Note: If you edit this property in an existing project, delete or move the associated trend files before you run the new runtime system. (For location of the trend files, see File Name.)

No. Files

The number of history files stored on your hard disk (for this tag) (4 characters maximum). The maximum number of files you can specify per trend tag is 999. Performance and storage will be severely impacted by having a large number of history files per trend.

If you do not specify the number of files, 2 history files are stored on your hard disk.


Note: If you edit this property in an existing project, delete or move the associated trend files - before you run the new runtime system. (For location of the trend files, see the File Name.)

Time

The time of day to synchronize the beginning of the history file, in hh:mm:ss (32 characters maximum). If you do not specify a time, the file is synchronized at 0:00:00 (i.e. midnight). The time needs to be specified in Greenwich Mean Time, not the local time zone.


Note: If you edit this property in an existing project, delete the associated trend files - before you run the new runtime system. (For location of the trend files, see the File Name.)

Tragically1969 is absolutely correct. I have a project where we keep trend files for 12 months and it works fine.

The period also works hand in hand in determining how long your trends are kept for, after this period the data is rolled over.

So if you have No. Files = 2 and period 24:00:00. Then the data is rolled over in each file every 24 hours and you would only save 2 days worth of data in the 2 files.

If you have No. Files = 2 and period = 1st. Then the data is rolled over each month and you would have 2 months of data in the 2 files.

You can have the period set as anything you want, day, week, month, year.

Storage method and sample period settings above this will impact the size of the files.

When you say 2 files are they named .000 and .001 ? Also is there a corresponding .HST file? And also let us know the trend tag setting for No. Files and period.