DL/T 860.91(IEC 61850-9-1) 变电站通信网络和系统第9-1 部分： 特定通信服务映射(SCSM) 通过单向多路点对点串行通信链路的采样值 -DL/T 860.91 (IEC 61850-9-1) communication networks and systems in substations Part 9-1: Specific communication service mapping (SCSM) by one-way multi-point serial c