ID #1215 May an internal siren be connected to the signaling device output on the GM/A? Carolina Bachenheimer-Schaefer 06.10.2016 11:00 0 Comments An Electronic Solid-State Siren for interior mounting can fundamentally be operated on the external siren output. It must be suitable for 12 V DC.However, a monitoring function by the GM/A 8.1 is not possible in this case. Tags: Alarm, APP, Security