Hi i am stuck in some process of tag change script.
First thing first, We don’t have any PLC and want to control the process on memory tags.
So i have one tank filled which i need to empty and transfer it to other tank. so there are some steps which need to be satisfied for the production process to complete which i am attaching below. So when i click on prod transfer start button, process start to step 1 checks the condition for step1 and goes to step2 check again step2 condition and goes on till step6.
I am controlling this from one tag of prod transfer start button but i am stuck in between on how to control the process based on steps. I have attached process image.
If you want to control like a PLC, you should execute like a PLC: Use a relatively fast timer event that checks all state every cycle and makes any necessary tag writes.
No, I don’t have any PLC right now so i am controlling through memory tag.
You misunderstood, I think. Phil is saying to execute like a PLC would.
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I dont have any idea on fast timer event. can you elaborate more on this and some solution.
They’re probably talking about a script running on Scripting>Gateway Events>Timer so it runs periodically and checks your current step and executes the necessary procedures, kinda like a PLC would
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Hi All, thanks for the inputs. I am able to solve the issue from timer tag. However i am stucking in write value to tag on read condition. can anyone solve this.
read = system.tag.readBlocking([’[default]FB_process/Test_tags/Finalised’])[0]
print read.value
print read.quality
print read.timestamp
if read == 1:
system.tag.writeBlocking([’[default]FB_process/Test_tags/prechecks’], [‘TRUE’])
I am able to read value but not able to write to it based on condition
Maybe change
if read ==1:
to
if read.value == 1:
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Still not worked. but when i change the condition to
if read != 0:
then write function works but for equal to operator it is not working.
Weird way to to work, what do you get on your print read.value ?
Hi leonardo, it is done on read.value. Thanks for this
I assume that this prechecks tag is intended to either have a value of 'TRUE' or 'FALSE', if so you should make it a booleen type and just write either True or False to it.
system.tag.writeBlocking(['[default]FB_process/Test_Tags/prechecks'],[True])