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2] data link (save memory function), 2] data link (save memory function) -2 – Sharp JW-21MN User Manual

Page 34

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9-2

(2) Register link

Mainly used for sending and receiving numerical data.

[Example] In the case of sending 1 byte data from a master station and slave station 01 and 02.

Register

Register

Register

Register

Register

Register

- The register link of the sending station may be used as D (Destination) side of the application

instruction of the PC program.

- The register link of the receiving station may be used as S (Source) side of the application

instruction of the PC program.

[2] Data link (Save memory function)

The save memory function is to provide a part of the data link area in the slave station data memory as
a receiving area. A slave station can receive only the required area by relay link/register link so that the
slave stations can save on use of the memory area.
As this function can unify the receiving area address and the sending area address of each slave
station, the same program can be used for each slave station. Mixed allocation of the addresses with
the data link (standard function) is also possible.

- Top address of receiving area in a slave station shall be set by the number of offset bytes from

the link area's top. (0

£

Number of offset bytes

£

total number of bytes of link area)

* When JW-21MNs without 30Hn mark and 30H mark are used, these cannot set each slave

station.
Automatically allocated with the same number of the sending bytes of the slave station.

Master station 00

Send

Receive

Number of offset bytes of
slave station "n"

Top address of slave station
"n" link area

Number of sending bytes
of slave station "n"

Top address of
slave station
"n" link area

Slave station "n" (JW-21MN: Set to save memory function)

Addresses are allocated as
receiving and sending alternately

Memory inside
control module

Memory inside
JW-21MN

V2

Number of sending
bytes of slave
station "n"

Available setting
each slave station

*

Top address of
master station
link area

Number of
sending bytes of
the master station

Receiving area
from slave station
1 to (n to 1)
Receiving area
from slave station
"n"

Top address of master station link area

Number of sending bytes of the master station

Number of offset bytes of slave station

Number of sending bytes of the slave station

Top address of slave station link area

Number of receiving bytes of slave station V2

*

Master station’s parameter

Set location

Setting item

Module No. switch of slave station

Slave station's parameter