Defines link procedures which are restricted to message transmission sequences operating with size 1 windows. It is one of a series of Standards applicable to telecontrol equipment systems. This Standard is identical with and has been reproduced from IEC 60870-5-2:1992.RECONFIRMATION NOTICETechnical Committee EL-050 has reviewed the content of this publication and inaccordance with Standards Australia procedures for reconfirmation, it has been determinedthat the publication is still valid and does not require change.Reconfirmed documents cannot be amended, but may be formally revised and a new editionpublished.Certain documents referenced in the publication may have been amended since the originaldate of publication. Users are advised to ensure that they are using the latest versions ofsuch documents as appropriate, unless advised otherwise in this Reconfirmation Notice.Approved for reconfirmation in accordance with Standards Australia procedures forreconfirmation on 31 May 2015.Reconfirmed documents cannot be amended, but may be formally revised and a new editionpublished.The following are represented on Technical Committee EL-050:Australian Industry GroupChamber of Commerce and Industry QueenslandEnergy Networks AssociationVictoria University