Freepbx limit concurrent inbound calls in a queue

I have 7 hard-phones in one queue and I’d like to limit the max amount of concurrent inbound calls to 1.

So all phones ring if someone calls inbound, but if one call is active any other caller will be queued.

Anyone know if there is a setting for this in Freepbx?

Info:
FreePBX 2.6.0.0
Asterisk 1.6.1.12

Thanks in advance.