Displaying text based on a tag value

Ignition
1

I’m looking to display text of my step description based on a tag value for the current step my machine is in using a text field.

For example, if the tag RXStep (which is bound to a PLC tag reading in an integer for the step a specific machine is in) reads 0 then print “Step: 0 Idle”.

I tried using If statements in Expression tab of the text field property binding window but keep getting errors no matter how I formatted them.

if ({Reactor_Status.RXStep} = 0, “Step: 0 Idle”)
if ({Reactor_Status.RXStep} = 1, “Step: 1 Pressurize”)
if ({Reactor_Status.RXStep} = 2, “Step: 2 Leak Test”)
if ({Reactor_Status.RXStep} = 3, “Step: 3 Calculate Product Qty”)
etc…

I have about 40 different steps. Is there a away to do this with a text field or better way to do this? I’ve looked at several forums but found nothing similar. Thanks!

1 Like
2

Is this Vision, or Perspective? Do you expect to need to add additional step labels frequently/ever?

3

Vision. No, these steps will likely never change.

4

You could use nested if statements but you’d need commas at the end of each line and closing brackets. Something like,

if ({Reactor_Status.RXStep} = 0, "Step: 0 Idle"),
if ({Reactor_Status.RXStep} = 1, "Step: 1 Pressurize"),
if ({Reactor_Status.RXStep} = 2, "Step: 2 Leak Test"),
if ({Reactor_Status.RXStep} = 3, "Step: 3 Calculate Product Qty"),
etc., etc.,
"Step: 40 Last step"
))))))))))))))))))))))))))))))))))))))))))))))))

The case function would be much easier:

case({Reactor_Status.RXStep}
  0, "Step: 0 Idle",
  1, "Step: 1 Pressurize",
  2, "Step: 2 Leak Test",
  3, "Step: 3 Calculate Product Qty",
  etc., etc.,
  "Step: 40 Last step"    // default
)

https://docs.inductiveautomation.com/display/DOC81/case

Tip: When posting code, select the block of code and press the </> button to format it. It will preserve indentation and do some syntax highlighting for you. It also prevents the forum engine putting in fancy “ ” inverted commas which have to be edited out when copying your post.

5

So, if you’re only doing this once, I like the case statement, or if you might want additional customization with each step, you can use the Style Customizer to bind arbitrary component properties (including text) to a driving property.

You could also store a dataset on a tag/client tag somewhere and use the lookup expression; that would allow you to update the text in one place (if you’re using this label in multiple windows).

6

Thanks so much! I will try these.

7

I tried the case statement just to test. I copied it exactly as shown below in the Expression tab of the property binding: text field window. I keep getting “Syntax Error on Token: ‘LONG CONST’ (Line 2 , Char 3)” error. Any ideas what could cause this? Are you able to use a tag as the value to inspect? I couldn’t find any examples using a tag instead of a constant.

case({Reactor_Status.RXStep}
0, “Step: 0 Idle”,
1, “Step: 1 Pressurize”,
2, “Step: 2 Leak Test”,
3, “Step: 3 Calculate Product Qty”,
“Bad!”
)

I also tried the style customizer, the only thing with the is that I would like one line of text to show if possible. The style customizer shows all the steps at once and takes up too much room.

Thanks again!

8

You haven't formatted your code properly again. (Re-read the tip in my previous post.) As a result we don't know if you have got “Step: 0 Idle” with "66 - 99" quotation marks or (what you should have) "Step: 0 Idle" with plain ASCII double-quotes.

Please edit both posts with the 🖉 edit link and then select any code blocks and press the </> button to format it. Check that the quote characters are the actual ones in your expression. Someone should be able to find the problem then.

1 Like
9

You’re missing the first comma

2 Likes
10

I had made a template for such things. Feel free to use if you find it helpful.

Step Indicator Example.zip (4.8 KB)

2 Likes