Viking Door Intercom Connecting to ATA-190

Question

I have a analog Viking W-1000 intercom connected to Cisco ATA-190 box, then into Cisco Unify Call Manager. Partition, CSS, etc have been set up, and for testing purpose, when an analog phone is connected to the ATA, once the handset is offhook, it immediately places a call to a specific number (front desk). And two-way voice communication is established.

However, when connected the W-1000 to the ATA, when the call button of the intercom is pressed (offhook), it rings (generates standard ring condence) and places a call to front desk. But the problem is, the call drops between each ring. And when the front desk phone is picked up, the W-1000 keeps ringing. It seems like Call Manger or the ATA considers each ring as a separate call instead of a tone of waiting for pick up.

Any idea what's wrong?

Answer 1

The W-1000 doorbox is designed to be connected to a Foreign Exchange Office (FXO or trunk input) of a phone system, or an ordinary telephone. It generates line voltage and AC ringing signal to call the phone system or ordinary telephone.

It is designed to interface directly with an unused analog telephone line input of phone system. ... When the “Call” button is pressed, the W-1000 generates a standard or custom ring cadence of an adjustable number of rings.

https://www.vikingelectronics.com/products/w-1000/

I think it's likely that you have connected it to a Foreign Exchange Station (FXS) or extension port on the ATA which is intended to connect to a standard phone with loop connect, and which also generates line voltage AC ringing to ring that phone.

In effect, you've created two phone lines together, not a line and a phone. You probably need to connect the W-100 to a FXO or 'line' input on the ATA, and not the 'phone' connection, then set the 'line' connection to forward the call over IP when it receives an incoming ringing call.

Every time the W-1000 sends a burst of AC ringing voltage to the ATA, the ATA is probably registering that as a hang-up and new call request.

If you can't change the ATA, you probably need to change the W-100 doorbox to a model that mimics a plain old telephone eg

https://www.vikingelectronics.com/products/e-10a/

The E-10A is a telephone line powered door entry phone designed to provide two-way handsfree communication. When the “Call” button is pressed, the E-10A will come off-hook and will remain off-hook until a CPC signal is detected, the programmed timeout has elapsed, a busy signal is detected, or the call goes silent, making the unit automatically disconnect.

The E-10A can be used with a Viking K-1900-5 or K1900-30 dialer, or connected directly to a CO line or analog PABX / KSU station when programmed as a ringdown circuit.

This video explains the difference:

https://www.vikingelectronics.com/fxo-vs-fxs-ports-know-the-difference/

Alternatively, you can use a Viking C-1000B controller between the W-1000 and the phoneline/ATA.

https://www.vikingelectronics.com/wp-content/uploads/documents/product_manual/W-Series.pdf