標準號：SIS SS-ISO 7809-1988
中文標準名稱：信息處理系統．數據通信．**數據鏈接控制程序．各級程序合并
英文標準名稱：Information processing systems — Data communication — High-level data link control procedures — Consolidation of classes of procedures
發布日期：1988/6/25 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：This International Standard describes the HDLC unbalanced classes of procedures and the HDLC balanced dass of pro-cedures for synchronous data transmission.Balanced operation is intended for use in circumstances which require equal control at either end of the data link. Operational requirements are covered in accordance with the overall HDLC architecture. The procedures use the HDLC frame structure defined in ISO 3309T and the HDLC elements of procedures described in ISO 43352).For the unbalanced classes, the data link consists of a primary station plus one or more secondary stations and operates in either the normal response mode or the asynchronous response mode in a point-to-pomt or multipoint configuration. For the balanced dass, the data link consists of two combined stations and operates in the asynchronous balanced mode in a point-to-point configuration. In each dass, a basic repertoire of com-mands and responses is defined, but the capability of the data link may be modified by the use of optional functions.