AbstractTagDriver with Ignition 8 - create new items when subscribed

Module Development
1

@Kevin.Herron
I have a module driver based on the AbstractTagDriver for Ignition 7.9
I convert it to Ignition 8.0

In this driver, DriverTag are added in AbstractTagDriver::itemsAdded when the ignition subscribe for new items.
I have too a few driverTags created when the module start.

I use Ignition 8.0.2-rc1 for my test.

For all the tag created when ignition subscribe, I have the status “Bad_NotConnected”.
It’s ok for the few tag created when the module start.

Note : In this case, the items can’t be browsed in the opc-ua server device.
So I directly put in the designer the string for the OPCItemPath. For example : ns=1;s=[my_device]my_address

I’ve tested with a Subscribed or Polled TagGroup, but I have the same result.

Is it a normal behavior in Ignition 8.0 ? is there a workaround ?

2

That this worked in 7.9 seems to be by accident; the driver wasn’t meant to handle adding tags dynamically after startup.

You might be able to work around this by overriding buildNode in your driver like this:

@Override
public void buildNode(String address, NodeId nodeId) throws AddressNotFoundException {
    // if address represents a tag that should exist in your driver, call addDriverTag
    ...

    super.buildNode(address, nodeId);
}
1 Like
3

Thanks a lot !
This has solved my issue.