Event Log type function needed

[PCSControls]

I would like to add the capability to log 'events' such as when selective items are turned ON/OFF or values changed by the operator etc. Does this functionality exist and I have not found it?

[Joe Tauser]

You can do this pretty easily with a single data table reporting the state of all parameters when one changes or multiple data tables for each parameter. If you post more detail I can hack an example together.

Joe T.

[PCSControls]

What I need to to have is an event log that can be displayed with a timestamp to indicate when things happened in the process or operator action. Typically would like to store last 200 events.

For example:

Display Triggered by

07:46:10 Flow Loop mode change to Auto mode (Indicates Operator changed modes, driven by mode change)

07:49:10 Irrigation Zone 1 ON (Started irrigation cycle, driven from state of a digital output)

08:15:12 Irrigation Zone 1 OFF (digital output shut off)

23:45:11 Zone 1 High Temperature Alarm (Alarm condition detected)

[Joe Tauser]

I'm guessing you want to display all this on the PLC screen. That's a bit more work.

Two solutions come to mind-

1. Use the built-in Alarms function and configure all your events as "alarms" with no reset or acknowlege. The time-stamping and logging take care of themselves. The only downside is it will look hokey.

2. Use two tables - one stores all your event descriptions and an index pointer. When an event happens, look up the description with the index pointer and stuff it into a second table with a timestamp, bumping all the rows down and putting the newest event at row 0. Then build a screen that will display the table rows of ASCII strings of the time and the descripton. You could use the arrow keys to increment/decrement a pointer that will retrieve selected groups of rows and update your ASCII variables.

It's really not as complicated as it sounds. Take a swing at it and let us know if you get stuck.

Joe T.