control output for 4621SW IP

[eokerb]

My department uses 4621SW IP phones and AWH55 headsets. We have the phone programmed to show when there is a call in que on the display. Is there any sort of device/accessory for this phone that will give an external output when a call is in que?

We used to supplement the call in que light with a external flashing light controlled by a Sonic Alert TR50.

http://www.sonicalert.com/Lamp-Flash-Telephone-Signaler-p/tr50.htm

However, that deviced depended on a separate analog line which we do not have at the new office.

Can any one suggest a device that will accomplish the same thing without requiring an analog line?

Thanks.