怎样看modbus规约报文

01 03 02 BC 00 38 84 44 //召唤YM

设备地址功能码（YM）协议地址(700) 寄存器数量CRC校验码

注意：一个遥脉占用两个寄存器数量，所以00 38表示28个遥脉

01 03 70 00 00 00 00 00 00 00 00 00 00 00 02 00 00 00 05 00 00 00 设备地址功能码（YM）字节数数据区

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0没0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 49 14

//4个字节表示1个YM 高字节在前低字节在后应答YM召唤

01 01 00 32 01 12 1C 58

设备地址功能码（YX）协议地址YX数量CRC校验码

01 01 23 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 设备地址功能码（YX）字节数数据区

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 F9 CB

//1个字节表示8个YX 应答yc召唤

01 03 02 58 00 2C C4 7C //召唤YC

设备地址功能码（YC）协议地址(600) YC数量CRC校验码

01 03 58 0D CB 0D C6 00 00 00 00 00 00 00 00 00 00 00 设备地址功能码（YC）字节数数据区

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 63 6D

//2个字节表示1YC 高字节在前低字节在后应答yc召唤

01 0f 01 90 00 0a 02 00 01 cd 01 //遥控令

设备地址功能码协议地址控制数量字节数数据区CRC校验码

01 0f 01 90 00 0a ce 02 //遥控令应答

01 0f 01 90 00 0a 02 00 00 cd 01 //遥控复归令

设备地址功能码协议地址控制数量字节数数据区CRC校验码

01 0f 01 90 00 0a ce 02 //遥控令应答

成功发完遥控令后，必须发遥控复归令清零。否则，这一遥控点下次不允许遥控。

注意：遥控令与遥控复归令的区别在于：遥控令的数据区不为0，遥控复归令的数据区为0。判断遥控不能成功的原因，就可以看遥控令的报文是否发到ecs方的中央控制单元，如果已经发出来了正确的报文，遥控不成功，原因在ecs方。如果遥控令没有发出来，或者发出的遥控令错误，则原因在dcs方。

判断通讯是否正常是同样的道理。