This part of IEC 60839 specifies the Open supervised device protocol (OSDP) for electronic 
access control systems. This includes communication settings, commands and replies 
between the ACU and the peripheral devices. It also includes a mapping of mandatory and 
optional requirements as per IEC 60839-11-1:2013 as covered by Annex F. 
This document applies to physical security only. Physical security prevents unauthorized 
personnel, attackers or accidental intruders from physically accessing a building, room, etc. 
This document does not in any way limit a manufacturer to add other commands to the 
protocol defined here.dition 1.0 2020-07 INTERNATIONAL STANDARD Alarm and electronic security systems – Part 11-5: Electronic access control systems – Open supervised device protocol (OSDP) IEC 60839-11-5:2020-07(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright ？ 2020 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or