S7-300透過MPI連結S7-200

剛好有案子需要使用S7-300向S7-200捉取資料

透濄MPI的通訊埠，S7-300可以直接向S7-200捉取資料，不需要再S7-200上另外編寫程式，程式直接寫在S7-300上即可，透過SFC67(X_GET)與SFC68(X_PUT)即可完成資料的傳送。

官方也列出了每種型號支援的連線數

S7-300的部份

The table below gives you information about the maximum number of connections available for S7 basic communication in the S7-300 CPUs.

CPU	Max. number of connections for S7 basic communication
CPU 312, CPU 312C	2
CPU 313	4
CPU 313C, CPU 313C-2DP, CPU 313C-2PtP	4
CPU 314	8
CPU 314C-2DP, CPU 314C-2PtP	8
CPU 315	8
CPU 315-2DP, CPU 315F-2DP	12
CPU 315-2PN/DP, CPU 315F-2PN/DP	14
CPU 316	8
CPU 316-2DP	8
CPU 317-2DP, CPU 317F-2DP	30
CPU 317-2PN/DP, CPU 317F-2PN/DP	30
CPU 318-2DP	30
CPU 319-3PN/DP, CPU 319F-3PN/DP	30
CPU 614	8

S7-400的部份

The table below gives you information about the maximum number of connections available for S7 basic communication in the S7-400 CPUs.
 

CPU	Max. number of connections for S7 basic communication
CPU 412-1 < FW V5.0	14
CPU 412-1 from FW V5.0	30
CPU 412-2DP < FW V5.0	14
CPU 412-2DP from FW V5.0	30
CPU 413-1	14
CPU 413-2DP	14
CPU 414-1	30
CPU 414-2DP	30
CPU 414-3DP	30
CPU 414-3PN/DP	30
CPU 416-1	42
CPU 416-2DP, CPU 416F-2DP	42
CPU 416-3DP	42
CPU 416-3PN/DP, CPU 416F-3PN/DP	42
CPU 417-4	42

詳情可參考西門子官方說明
How does data communication work between S7-300/S7- 400 and S7-200 via MPI using S7 basic communication?

這裡可以下載範例程式
System Software for S7-300/400 System and Standard Functions  ID:1214574 

或可以升級成Profibus通訊 (來源:bob的網站)
如果使用者想要有更快的通訊速度，可將S7-300升級到PROFIBUS DP，S7-200外掛EM277。關於S7-200 EM277的用法，請連結到 ID: 1109582


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參考資料  鮑伯的PLC事件