Table of Contents
Advertisement
16 COMMUNICATION BETWEEN CPU MODULES IN MULTIPLE PLC
SYSTEM
16.3.2 Reading and writing device data
16 - 12
It is possible to read and write device data into the Motion CPU/PC CPU module from
the High Performance model QCPU with the the communication dedicated instructions
between multiple PLCs listed in the table below.
(Reading or writing can not take place from the High Performance model QCPU to the
High Performance model QCPU, Motion CPU to the High Performance model QCPU,
or Motion CPU to Motion CPU.)
Instruction name
S.DDWR
Writes host CPU device data into other CPU devices.
SP.DDWR
S.DDRD
Reads other CPU device data into the host CPU.
SP.DDRD
S.GINT
Requests start up of other CPU interruption programs.
SP.GINT
For example, High Performance model QCPU device data can be written into the
Motion CPU's device data with the S.DDWR instruction of the communication
dedicated instruction between multiple PLCs.
High Performance model QCPU
S.DDWR instruction
Reads the device
memory
Device memory
POINT
One High Performance model QCPU can operate up to 32 " Motion dedicated PLC
instructions " and "communication dedicated commands between multiple PLCs
(omitting the S (P).GINT instruction)" at one time. However, if the Motion dedicated
PLC instructions and communication dedicated instructions between multiple PLCs
(omitting S (P).GINT instruction) are made at the same time, the instructions will be
executed in order from the first instruction accepted. If there are 33 or more
unexecuted instructions, an "OPERATION ERROR (error code: 4107)" will be
triggered.
REMARK
Refer to the Motion CPU Programming Manual for details on and the necessity of
use of the communication dedicated instructions between multiple PLCs.
Description
Writes in the
device memory
Device memory
MELSEC-Q
CPU module
Motion
PC CPU
CPU
module
Motion CPU
16 - 12
Advertisement
Table of Contents
