Get SQL error from stored-procedure transaction group

I’m inserting data into a 3rd party MySQL database using a stored procedure they created and maintain. I’d like to get the error that is generated by their stored procedure if I have an error logging data so I can flag the operator.

They are using the SIGNAL SQLSTATE code and then a message. Is there any way I can capture that to a tag? It shows up in the event area of the transaction group. I’ve tried to shove the return and output param to a string but I can’t seem to do it.

An example of what they are doing is here:

SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'There are not any active Storage Unit with the specified name';

I’d like to capture the MESSAGE_TEXT part of it. Any possible way to grab it?