Yaskawa MP920 Communications Module - Manual (Page 267)

Appendix B 218IF Messages
B.2.1 Message Configuration
B-18
B.2 MEMOBUS Messages
B.2.1 Message Configuration
The message configuration shown below is for messages used by the 217IF and the 218IF.
For details, refer to the MEMOBUS Document: MEMOBUS Descriptive Information (SIE-
C815-13.60).
When data is transferred with the MEMOBUS protocol, each message consists of two ele-
ments: A header and application data. Unlike the Extended MEMOBUS protocol, there is no
EIF header.
The TCP/IP header shown by the dotted lines can be handled only by the 218IF. Only appli-
cation (MEMOBUS) data is transmitted and received by the 217IF.
The header is used for TCP/IP and UDP/IP. The user program need not be aware of this
header because it is automatically added or deleted by the 218IF.
The actual data for the MEMOBUS protocol is stored in the application data.
The application data has the parameter structure shown below, according to the remote sta-
tion handling code that is set in the connection parameter.
No. Communications
Protocol
Code Reference
1 MEMOBUS messages RTU B.2.2
2 MEMOBUS messages ASCII B.2.3
Header
TCP/IP header
(218IF only)
MEMOBUS messages:
Only this part is handled by the application program.
Application (MEMOBUS) data