SFC Transition Timeout delay Expression examples

Ignition
1

In SFC, in a transition, as a Timeout Delay, we can specify expressions

I know that I can specify a number or basic expressions with tag, but I can't find a way to have a variable as a base path for my tag.

{[default]full/path/to/tag} # Working
{chart.basePath + "/to/tag"} # Not working
tag({chart.basePath} + "/to/tag") # Not working
{{chart.basePath} + "/to/tag"} # Not allowed
2

This would be the syntax I would expect to work. What if you evaluate {chart.basePath} + "/to/tag" separately (and dump it out as a string to the logs) to be sure it's what you think it is?

3

to avoid any confusion, mistake, typo, and so on, I just did the following, but it is still not working

tag("[default]full/path/to/tag") # Not working

Edit: For info, I'm on Ignition 8.1.35

1 Like
4

Huh, well. That's definitely not what I would expect. I'll dig in a little more later today.

6

In my case, I am not interested in the cause. I already know the SFC is waiting for a machine to execute a task. If the task is not executed fast enough, SFC have some other action to execute (slow down another process).

I want to use a tag value as the timeout delay, with a calculated value based on machine setup, and recipe requirement. This way, the timeout would be optimized even if the machine setup is changed. Unfortunately, it is not possible at the moment