BS 4505-2: BRITISHSTANDARD 1990 ISO 1177:1985 Digital data transmission- Part2Characterstructurefor start/stopandsynchronous transmission NOCOPYINGWITHOUTBSIPERMISSIONEXCEPTASPERMITTEDBYCOPYRIGHTLAW BS4505-2:1990 Committeesresponsibleforthis British Standard The preparation of this British Standard was entrusted by the Information SystemsTechnology StandardsPolicy Committee (IST/-)to Technical Committee IST/6,upon which the following bodies were represented: AssociationforPaymentClearingServices British Computer Society British Telecommunications plc Business Equipmentand InformationTechnologyAssociation Department of Trade and Industry (Information Technology Standards Unit) Department of Tradeand Industry (National Physical Laboratory) ElectricitySupplyIndustryin Englandand Wales ElectronicEngineeringAssociation HM Treasury (Central Computer and Telecommunications Agency) Institute of Data Processing Management Inter-UniversitiesComputing Committee Joint Network Team National Computing Centre Ltd. National Health Service OFTEL(Office ofTelecommunications) PostOffice Telecommunication Engineering and Manufacturing Association Telecommunications Managers Association This British Standard, having been prepared under the direction of the Information Systems Technology Standards Policy Committee, was published under the authority ofthe Board of BSI and eomes intoeffecton 30 June 1990 BSI 03-1999 Amendments issued sincepublication First published in September1969 Amd, No. Date Comments Second edition June 1990 The following BSI references relate to the work on this standard: Committee reference IST/6 Draftfor comment 89/62747DC ISBN0580182088 BS4505-2:1990 Contents Page Committeesresponsible Inside front cover National foreword i 1 Scopeandfieldofapplication 1 2. References 1 3 Bit sequencing-Start/stop and synchronous operation 1 4 Parity bit-Start/stop and synchronous operation 1 5 Parity sense-Start/stop and synchronous operation 1 DTEreactiontoparityerror 1 6 Character framing 7 2 Publicationsreferredto Inside back cover CBSI03-1999