UDT values "NoneType" when vision page internalFrameActivated

Ignition
1

Hi All.

Ignition 8.1.1 (b2020120808)

I have a strange thing happening when running a script in the internalFrameActived event of my window

When I open the window I get:-

Traceback (most recent call last):
  File "<event:internalFrameActivated>", line 23, in <module>
TypeError: unsupported operand type(s) for &: 'NoneType' and 'int'

The code is pretty straight forward

headers = ["Device Name","Status"]
data = []

window = system.gui.getParentWindow(event).getComponentForPath('Root Container')

indevs = system.dataset.toPyDataSet(window.inputdevices)

for row in indevs:
	id = row["value"]
	desc = row["DeviceName"]
	#read the status of the associated tag index
	if id < 32:
		ok = window.safetyfunction_hmi.SDI_OK_0_31
		fp = window.safetyfunction_hmi.SDI_FP_0_31
	else:
		ok = window.safetyfunction_hmi.SDI_OK_32_63
		fp = window.safetyfunction_hmi.SDI_FP_32_63
		id = id - 32
	#make the bit
	id_mask = 2 ** id
	#see if this bit is on
#	try:
	ok_bit = (ok & id_mask)
	fp_bit = (fp & id_mask)
	#set the text
	if fp_bit > 0:
		data.append([desc,"Fault"])
	elif ok_bit > 0:
		data.append([desc,"OK:"])
	else:
		data.append([desc,"Tripped:"])
#	except:
#		data.append([desc,"Pending:"])
#		pass	
	
system.gui.getParentWindow(event).getComponentForPath('Root Container.Table').data = system.dataset.toDataSet(headers,data)

safetyfunction_hmi is a UDT parameter and line 23 where the error occurs is “ok_bit = (ok & id_mask)”

Any reference to the UDT returns a NoneType including the meta data.

Now it gets pretty strange, if I add a system.gui.messageBox(“Test”,“Test”) before the for loop. The code works perfectly fine.

(similarly adding the code to a button on the window works perfectly fine too)

Any info greatly appreciated

Regards
Dave

2

Tag data arrives asynchronously. You are simply accessing that property before the data arrives. Consider moving this code to a propertyChange event that notes when the UDT parameter populates.

3

Thanks pturmel

You learn something new every day.
I hadn’t realised that parameters were asynchronous.

Does that mean I shouldn’t use any parameters in window and internalframe events? or is it purely a UDT issue? (my table and string parameters have never suffered NoneType)

I will look to move the code elsewhere.

Regards
Dave

4

Not sure. I never use UDT parameters, whether for windows or for templates. I always pass tag paths and indirect bind from that.

1 Like
5

Thanks pturmel.

I will try passing in the path instead of the UDT.

regards
Dave