Specifications

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(2) Open processing
(a) The open processing is a processing which enables data communication with
external devices.
1) In TCP/IP communication
• The Ethernet module system communicates with an external device
using a connection after establishing the connection (connection of logic
circuit).
• The users can send and receive data using the connection after
completing the open processing normally.
2) In UDP/IP communication
• The Ethernet module system performs the internal processing.
• The users can send and receive data through the open connection after
completing the open processing normally.
(b) In order to perform the open processing, the initial processing must have
been completed normally.
(c) Connections can be opened for up to 16 external devices.
Note that two fixed buffers are required when communicating with the same
external device using the fixed buffer communication. Because of this, the
number of the external devices may be reduced.
POINT
Note the following when performing the communications using the MC protocol
and the random access buffer.
• To continue data communication even after turning the PLC CPU of the
Ethernet-module-installed station to STOP, set "Initial timing" to "Always wait for
OPEN (Communication possible at STOP time)".