Alarm systems - Alarm transmission systems and equipment - Part 2-4: Requirements for equipment used in systems with voice communicators using the public switched telephone network; German version EN 50136-2-4:1998
报警系统.报警传输系统和设备.第2-4部分:使用公共交换电话网络的语音通信系统中使用的设备要求;德文版EN 50136-2-4:1998