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MELSEC-Q
7 DATA COMMUNICATIONS USING BIDIRECTIONAL PROTOCOL
7.2.2 Arrangement and contents of the transmission area and the transmission data
This section explains the arrangement and contents of the transmission area and the
transmission data for performing data transmission using the bidirectional protocol.
For details on the contents of transmission data, see Section 7.1.2 (3).
(1) Transmission area
The transmission area is a memory area for storing the data and the data count
that are transmitted from the PLC CPU to the external device via the Q series
C24. By default, the transmission area is assigned to addresses 400
H
to 5FF
H
(CH1 side) and 800
H
to 9FF
H
(CH2 side).
400
H
401
H
5FF
H
CH1 side
address
(Default)
to
Buffer memory
Transmission
area
Transmission data count
designation area
Transmission data
designation area
The unit of transmission data count
(words/bytes) is in accordance with the
word/byte units designation in GX Configurator-SC.
Transmission data count
The transmission data count designated with the
BIDOUT instruction is written, and sent as the
data length.
Transmission data
The transmission data designated with the
BIDOUT instruction is written and then sent.
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