Is it possible to configure one of Plesk servers as master DNS only and without any hosting and other Plesk servers with slave DNS.
In case if you need to configure the slave DNS server for Plesk server you need follow the steps in official documentation at:
If you need to use a Plesk server which has customer's data as slave DNS server for other Plesk instances I would recommended you to check our product PPA which has desired functionality: http://sp.parallels.com/products/plesk-automation/
It will allow to use separate service nodes (i.e. DNS servers) according your needs.