Mitsubishi Electric MELSEC-L Series - Communication Type of Protocols

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11.2 Communication Type of Protocols
Receive and send packets from/to the connected device for the process execution are registered in a protocol. Packet
elements set using the predefined protocol support function correspond to the data part of the send/receive packets.
The following shows an example of packet configuration. For details on the packet elements, refer to Page 346,
Appendix 8.3.
(1) TCP/IP
(2) UDP/IP
Communications with the connected device using the predefined protocol function are performed with the
following procedure (communication types).
For the operations of each communication type, refer to Page 339, Appendix 8.1.
Communication type name Description
Send Only Sends a send packet once.
Receive Only Receives a packet if it matches any of up to 16 defined receive packets.
Send&Receive
Sends a send packet, then receives a packet if it matches any of up to 16 defined
receive packets.
Maximum data length: 1514 bytes
Header
Ethernet header TCP/IP header
40 to 1500 bytes
Destination
MAC address:
6 bytes
Sender's MAC
address:
6 bytes
Type:
2 bytes
IP:
20 bytes
TCP:
20 bytes
Data
Maximum data length: 1514 bytes
Header
Ethernet header UDP/IP header
28 to 1500 bytes
Destination
MAC address:
6 bytes
Sender's
MAC address:
6 bytes
Type:
2 bytes
IP:
20 bytes
UDP:
8 bytes
Data