| 摘要 |
<p>The invention relates to a method and control arrangement to secure an alarm system in a site to be monitored. The alarm system's readiness of forwarding an alarm out of the site is being monitored with a control arrangement belonging thereto, by which at least data transmission connections of the alarm system to outside the site are being repetitively checked in order to enable sending the alarm via one or more secondary alarm connections in case the primary alarm connection is prevented. The control arrangement comprises at least two controlling devices (1, 1 ') that monitor continuously the site's (K) electric connection/readiness to at least two communication channels.</p> |
