OSDP (Open Supervised Device Protocol)

An open, bidirectional, SIA-standardized reader-to-controller protocol — the modern replacement for the one-way wiegand reader protocol. OSDP runs over RS-485 and supports OSDP Secure Channel (AES-128 encrypted command + response), tamper detection, configurable LED/buzzer feedback, and remote firmware updates.

OSDP is the right answer for new enterprise deployments — Wiegand is unsupervised, plaintext, and vulnerable to wire-tapping attacks. SIA OSDP versions: v2.1.7 (2015), v2.2 (2022). v2.2 added more granular Secure Channel session key rotation.

AE Guardian and the PACS connectors don't directly drive readers — the PACS panel handles that — but the reader-protocol choice affects what AE can expect to surface in soc-insights. OSDP readers report richer diagnostic data than Wiegand readers (tamper status, link health), which Guardian can ingest into SOC dashboards if the upstream PACS captures it.