Helixnet: How do I wire up the extra buttons a on HRI-12B unit
1. The extra connectors for keys 13-40 are on Phoenix connectors on the inside of the inside of the unit. There is no extra board although you should note that the connectors are not supplied.2. We do not sell mounts or backboxes for these units.3. The HRI-12M is physically smaller than the HRI-12B and IKB-12PKeep in mind that the HRI and IKB systems are a single channel partyline system where the user of the station is placed on the partyline when the handset is taken off-hook, with call signalling on the keys.Make sure to include in your system an HMS-4X, HLI-ET2, HCS v2.1 firmware, and HS-6's for the stations.