YASKAWA MP3000 Series User Manual

Also see for MP2000 Series: User manual User manual User manual User manual Driver manual

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YASKAWA MP3000 Series User Manual Manual pdf 420 page image

2.16 Details on ProtocolsMEMOBUS Protocol2-402MEMOBUS ProtocolMessage StructureThe following message structure is used in communications with 217IF and 218IF Modules. Refer to thefollowing manual for details.MEMOBUS Descriptive Information Industrial Communication System (Manual No. SIE-C815-13.60)When the MEMOBUS protocol is used to send and receive data, each message consists of two fields: aheader field and the application data field. The 218 header that is used for the Extended MEMOBUS pro-tocol is not used.The header is for TCP/IP and UDP/IP connections and is used only for Ethernet communications. Userprograms do not need to be aware of this header because it is automatically appended and removed in the218IFD.When communicating using the 217IF, only the MEMOBUS application data field is sent and received.The structure for parameters in the application data field is given below. The actual data for the MEMO-BUS protocol is stored in the application data field.Communications Protocol Code ReferenceMEMOBUS message communications RTU MEMOBUS RTU Mode (page 2-404)MEMOBUS message communications ASCII MEMOBUS ASCII Mode (page 2-409)Whether RTU or ASCII is used for Ethernet communications depends on the code setting for theremote station in the connection parameters. When communicating with a 217IF Module, this is deter-mined by the communications mode setting in the communications parameters.When a message is received in Ethernet communications, neither the CRC-16 in RTU Mode nor theLRC in ASCII Mode are checked. Error checking for received messages is performed using errordetection in the TCP, UDP, and IP headers. It is therefore not necessary to calculate the CRC-16 orLRC when sending a message.Header MEMOBUS application dataMEMOBUS MessageApplication will use onlythis field.TCP/IP header(only for Ethernetcommunications)Note