Open Supervised Device Protocol (OSDP) is an access control communications standard developed by the Security Industry Association (SIA) to improve interoperability among access control and security products.
OSDP based on RS-485 communication lines and provides high performance and stability to Access control system.
AC-825IP support OSDP communication while the supported devices are x-805 expansions units (R/S/D/P) and 3 OSDP reader.
All devices connected to the OSDP bus have to be connected as a daisy chain and addressed accordingly, here is a diagram that explain the connection on AC-825IP access control panel:
The AC-825IP also support 2 reader connected to the OSDP bus, the readers have to be set to address 13 and 14 addresses.
The maximum distance between the AC-825IP and last OSDP unit is 1000 meters.
Please note that a 120 Ohms resistor need to be installed on the last X-805\ Reader on the OSDP line in parallel to the OSDP A/B
Please note that the cable must be 2 pairs – twisted and shielded 18-AWG