Studio 5000 Trends - How do they function?

[Mullet]

Hey guys. First post, sorry if I'm doing this wrong.

Some of us were wondering about building trends in Studio 5000 for Compact or ControlLogix controllers.

Can you setup a trend to run locally on the controller and come back to collect data later, or does it only work while you're Online with the controller and only for you in that instance?

I haven't used trends much in Studio (as you can tell) and I tried doing some Google searching but didn't find too much. I even went onto RAU and tried to search for any courses related to "Trend" and got zip. If anybody had in-depth information on how they work that would be great.

Thanks for any information you guys have.

 

[Cheeseface]

The trends are a function of Studio 5000, not the PLC.

You need some sort of data logging software to do what you want. There are many, IBA and Ignition the easiest. There's also the pylogix module for python, which I recently found out about.

 

[Operaghost]

The trend in RSLogix/Studio 5000 can log to your hard drive. But as mentioned, it is a function of the software so your PC has to remain connected with the trend window opened (doesn't have to be visible) in order for it to log data.

That really isn't the intent of the tool. It is meant more for real-time viewing rather than historical viewing. If you need to log data you need to use another tool. Most HMIs have this capability.

OG

 

[Mullet]

Thanks guys I appreciate the responses! That helps!

 

[Peter Nachtwey]

The trends are a function of Studio 5000, not the PLC.

It is the PLC that gathers the data and the PLC should gather the data at consistent intervals and the shorter the interval the better.

Trends don't get used as much as they should. Trends are essential for debugging/tuning motion control applications.

A trick that I used to plot variables like a state number or some other thing important like a temporary value in a calculation that may change rapidly if looking at in in ladder.

 

[kekrahulik]

The other nice option in the trend setup is that you can trigger it to start based on a certain condition, stop on a certain condition, and run a short time after the stop trigger.

I have used this to capture those nagging events that happen randomly. I give the trend a stop trigger, then start the trend running and go home for the night. In the morning I come in to a nice trend capture of the event.

 

[JeremyAdair87]

PLC Trends are used for seeing extremely fast scan times. We need them at the PLC level because the HMI is polling at around 500mS. Those trends don't let us see coding issues. Its a different use case compared to an HMI or Scada Trend. On the PLC you can see the data every 10mS. You can see a bit turn on and off in a single scan. Think of it like your own personal Oscilloscope for bits. Do not think of it as an HMI trend.

Use studio 5000 trends for debugging, and creating timing diagrams for bits/logic. They are typically super high resolution but don't cache data for any substantial length of time. Its a debug tool, not a heavy data collection tool.

I've used trends at the airport going to a site with an issue. I created 4 or 5 troubleshooting trends, and exported them. I showed up to site, I imported my trends quickly and found the issue very quickly because I had played compiler waiting on the plane to take me to the plant.

I've set trends up on a super slow polling speed over 30 min. I went and hit every estop in the plant (the polling speed was 1 bit of data every 2 seconds).

You can run multiple trends at once. I've had 7 or 8 going at a time. (I ran out of room on the screen to start and stop them all)

You can export the data from a trend to a CSV file and manipulate the data in a less clunky environment like excel.

There is a way to leave your PC on and store the data to your PC, I never fooled too much with it.. Correction, I couldn't get it to work. (yes you must be online to trend. Its in studio 5000 on your pc. Its not inside the PLC)

There is a way to make your trend start and stop based on a bit. Again this is a troubleshooting application.

Here is a guide on using trends. https://www.solisplc.com/tutorials/...g-trends-in-allen-bradley-rslogix-studio-5000

IMO the easiest way to get permanent trend data is to use ignition. I would set up ignition, Attach a database, then I would use a transaction group. Full tutorials are here. https://www.inductiveuniversity.com/courses/ignition/transaction-groups-in-ignition/8.1 it could cost around a grand or 2 just for the database drivers, AB drivers and the transaction group stuff. Their system is modular so you can buy it in pieces. If you bought everything including the MES 3rd party stuff, the whole thing is around 30k

If you enjoy troubleshooting, scripting and the plant can't afford anything, a rasberry Pi and the pylogix library will get plc data pulled into python for you. then you would have to poke around to get your own trends made.
https://github.com/dmroeder/pylogix (dmroeder is on this forum and the reddit forums)

I've also seen HMI scripts for recording data to an SD card. Here is a link if you are using Factorytalk.

I've also seen people max out a PLCs memory creating arrays and their own homebrew data collection.... don't do that by choice. I can't recommend it.