$blob_id = ibase_blob_create();
ibase_blob_add($blob_id, "test"); 
$blob_id_str = ibase_blob_close($blob_id);
$st = "INSERT INTO bltable (NUMMER,OPMERKING) VALUES (1,?)";
$result = ibase_query($st,$blob_id_str);

This gives an access violation.
the table bltable contains two fields
NUMMER, integer
OPMERKING, blob