Null values on datatypes after restore

Ignition
1

Hi guys,

I have a question regardin tags on datatypes. I just restored a project (including datatypes and tags) from a gateway backup that used to work fine.

The problem is that half of my pressure sensors don’t transmit data anymore (null value - pic1).

ex2
ex2277×513 32.5 KB

I already verified the registers address to be correct in the UDT’s and check if the values appear on the PLC Local HMI, and there they show the values.

ex1
ex1728×153 38 KB

ex3
ex3780×591 51.5 KB

Does anyone have an ideea on what the problem should be?

Thank you in advance!

2

Just compared the OPCItemPath too, and are identical.

EX5
EX51542×681 130 KB

3

Use the OPC client in the gateway to manually read the values, this way you can rule out the possibility that the formatting changed for the OPC server.

Also, if your datatype has any empty values that the path relies on you need to be careful with that. With version 8 a bug came back that initializes empty tags in a datatype as “NULL” instead of a 0 if it is a number or an empty string “” if it is a string. This is why we can’t go to 8 yet.

1 Like
4

Thank you!