发表于:2004-02-10 08:54:00
7楼
硬件:CP 341 or CP 441-2
下面是西门子手册里面一些
The transmission protocol used is the GOULD - MODBUS Protocol in RTU
Format. Data transmission is carried out in accordance with the Master-Slave
principle.
The Master (SIMATIC S7) has the initiative during the transmission.
Function Codes 01, 02, 03, 04, 05, 06, 07, 08, 11, 12, 15, and 16 can be
used for communication between the CP and the host system.