OPC Items not showing value from Siemens PLC

I have setup a transaction group with OPC items to a siemens PLC. the values for the items say waiting. i can see values for the addresses when I view them in sqltags. attached is a log with trace turned on for the siemens driver.

SiemensPLCLog.gz (922 KB)

Are the values coming through in the database? Is the group triggered?

I would check Status>OPC to see if the items are properly subscribed and have values there. I suspect it could be a problem with the addressing in some way. The “waiting” would indicate that the items simply aren’t getting any type of value update.


The database table is being filled with NULLs.

I do not have a trigger set.

The problem was the addresses. I thought they were the same as the address used in my SQLTags, but come to find out they did not match the addresses used in SQLTags.

Thank you,

quick follow up. how come i cannot see the current value of the items in the group when the group is disabled?

You can’t right now, the values only come in when the group is running.

Right, unfortunately this was something that was lost when going from FSQL to SQL Bridge. We hope to get it back in in the next version of the SQL Bridge (maybe Q4-Q1 '12).