Thanks to input from the forum I have now been able to improve my dynamic block for data extraction. As yet I have only used the old version on a couple of drawings so this is not a big issue but I would like to know if it can be done.
I inserted the "updated version" of the block saying yes to redfine the block when asked. however I found that the visability state changed on them to all being the same as the initial one in the block.
What I would like to do is re-insert the block but retain the visability state currently chosen for each instance of the block in the drawing.
2 smoke detectors are shown as heat
3 detectors are shown as Optilcal
After re-insering all blocks are now shown as heat.
If this has to go down the route of lisp routines I will hold my hands up & say sorry I'm lost!
Thanks for any replies