Valcom V-2904 audio intercom system

4 Door Answering Device - Activates Door Locks - Four zone/talkback door entry control for handsfree communication with remote call in. Provides background music input with volume control, door unlock contact closure, built-in ring generator with on/off switch, alarm function input, places simultaneous calls in queue.

- Provides Handsfree Talkback Communication Between Up To 4 Entryways And A Telephone.
- Transmit And Receive Volume Controls.
- Built In 90 V 30 Hertz Ring Generator With On/Off Switch.
- Integral Battery Backup Input.
- Distinctive Ringing Option.
- Programmable Number Of Ring Cycles.
- Ringing Automatically Discontinues After Programmed Number Of Cycles Or Upon Answer.
- Compatible With All Valcom Doorbox Speakers.
- Interfaces With Telephone System Via Loop Start Or Ground Start C.O. Line Position.
- May Be Accessed From A Dedicated Single Line Telephone Set.
- Supports Call Buttons At All Speaker Locations.
- Tone At Door Speaker When Call Button Activated.
- Standard 66 Block Used For Connections.
- Normally Open And Normally Closed Door Unlock Relay Contacts.
- Door Unlock Relay Available On A Per Door Basis.
- Programmable Door Unlock Codes.
- Alarm Functions.
- Simultaneous Calls Placed In Queue.
- Background Music Input.
- One Way All Call To All Speakers.
- Optional Alert/Repeated Alert Tone.