Yaskawa MP940 - Manual (Page 106)

4.2 Serial Communications Function
4-13
4
Message Flow
All standard MEMOBUS messages are exchanged between the MP940 and the SERIAL
Module.
The SERIAL Module communicates with the MELSEC Controller and performs standard
MEMOBUS and MELSEC message conversion processing. There is no need for the
MELSEC message configuration to be recognized by the user application. The user can eas-
ily communicate with the MELSEC Controller by using the MSG-SND and MSG-RCV
functions and specifying MELSEC as the transmission protocol in the SERIAL parameter
settings.
Due to MELSEC protocol-specific restrictions or MELSEC sequencer-specific restrictions
in MEMOBUS to MELSEC format conversion, there are stricter restrictions than in the
MEMOBUS protocol, such as the number of words read from a register. Carefully read the
manuals relating to the devices being connected.
Also be sure to refer to the manual relating to MELSEC protocol type 1 commands.
MP940
CPU
SERIAL MELSEC
Serial
MELSEC
messages
Protocol
conver-
sion
Local
station
Standard
MEMOBUS
command
Messages
Remote
station