Which formats are used most in US monitoring stations?

• A. CID
• B. SIA
• C. CID and SIA
• D. NEMA

Answer: (C)

Two formats dominate US monitoring stations: CID (Contact ID) and SIA (Security Industry Association) format. CID has been a longtime workhorse, giving central stations a standardized way to interpret alarm events and identify accounts. SIA was developed to provide a flexible, extensible alternative as panel technology and monitoring networks evolved, offering broader event types and options. Because many panels can output either CID or SIA, and central stations often accept both, most monitoring facilities effectively handle these two formats. NEMA, while important as an industry standards body, is not a primary reporting format used for transmitting alarm events, so it isn’t among the formats used most.