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MELSEC-F
COMMUNICATION USING MC PROTOCOL8
8 - 4
8.1.4 PLC setting for performing data communication
Data communication via MC protocol is enabled by adjusting the following settings
using FX Configurator-EN-L and writing the parameters to the Ethernet module.
1) Operational settings (see Section 4.6.)
2) Initial settings (see Section 5.2)
3) Open settings (see Subsection 5.5.2)
8.1.5 Precautions on Data Communication
This section explains some precautions that should be observed when performing
data communication between an external device and the Ethernet module.
(1) Precautions that should be observed when performing data communication via the Ethernet module
(a) Perform read/write only when the buffer memory status of Ethernet module
is the following.
If the initial normal completion signal (BFM# 27 [0001H]) and the open
completion signal (BFM#20480 corresponding bit) of the used connection is
ON (open completion status), it is possible to communicate from an external
device using MC protocol without regard to the existence of a sequence
program. (Only connections No. 3 and 4 are available in communication
using MC protocol.)
(b) Use the UDP connection set to "Always wit for OPEN (BFM #24 b8: ON)" in
the initial timing setting in the operation settings. Or use the passive open
connection in the case of TCP.
(c) Communication using MC protocol is enabled only when the communication
parameter for an open connection is set to "MC protocol usable" in
"Connection usage" as described in the table in Subsection 5.5.2.
To set this using FX Configurator-EN-L, select the open settings from the
initial screen, and when a protocol is TCP, select [Unpassive(MC)] or
[Fullpassive(MC)] in [Open system].
(d) Replacing the Ethernet module
The Ethernet address (MAC address) differs depending on the device.
When the Ethernet module is replaced due to breakdown, reboot any
external devices also.
Similarly, reboot the Ethernet module even when an external device is
replaced (such as a personal computer).