@yoluko
At first glance, I'd say your plugin call looks fine, and the issue is that you have it in a parallel event that doesn't appear to stop itself. The command is being run on every frame, so it is continually adjusting the timer to be one second later than the current time. There's no pause there where the timer is just allowed to run on its own.
What is turning on switch 19? What is turning it off?
If this is something you want to do in a loop, I would do it this way:
Have one event that's going to kick the whole thing off. That will call the plugin command to turn on switch 19.
In your common event, set to parallel and conditioned by switch 19, do a Control Variables to add 1 to your time variable, then call the same plugin command to turn on switch 19 in 1 second, and then a Control Switches to turn OFF switch 19.
That means the common event will only run ONCE each second (or however long you set the timer for), and will only run again when the timer has expired.