Busy Lamp for Entrance Door

Unanswered Question
Nov 7th, 2007

Dear experts,

we need a solution for one of our customer. We change a Siemens PBX and customer now gets a Cisco CCM (we are happy that we kicked them out) but we have now a little problem. What Siemens did for customer is the following.

.) If customer is making a phone call, a red lamp outside the room is going on, so that people outside recognize, that the person inside is busy and on the phone and do not enter the room.

How can we realise this with CCM? What we should also think of is that the wiring to this lamp is from where the phone is now to the lamp directly and not somewhere centralized (lets think of busy indication from CCM)

Need help,



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I have this problem too.
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Paolo Bevilacqua Wed, 11/07/2007 - 09:04


this is not easy to do. Some 79xx phones have an RS-232 to which you con connect a device to do things, but the communication protocol is not documented and may required substantial reverse-engineering.

The alternative is to modify a phone and hook a relay to the line button.

Hope this helps, please rate post if it does!


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