Sandman has a couple devices that may work. http://www.sandman.com/
24VDC latching relay controlled by a couple Modular Ring Relays.
Wire latching relay to select one of two lines, and Modular Ring Relays on each line ahead of the latching relay.
From: Barry Walters [mailto:Barry.Walters@SalemMedia.com]
Sent: Thursday, August 16, 2018 6:55 AM
Subject: [CRTech] Phone Line Selection
Hello Brain Trust…Looking for a way to have a Burk remote control answer two separate incoming POTS (think main/backup). Wanna keep it as simple as possible. Found one device online from Malaysia ($35.00) that should work, but their website ordering is broken: http://www.mycomsolutions.com/ax520/ax520.htm. Thought about relay driven by ringing voltage on “line two”. Needs to be pretty foolproof.
Barry Walters | Director of Engineering- Dallas | Salem Media Group, Inc.
6400 N. Beltline Rd, Irving TX, 75063
Phone: (972) 707-6905 | Mobile: (303) 549-1009 / Email: Barry.Walters@SalemMedia.com