Frame Settings; Jumbo Frame; Communication Speed - Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual

Frame Settings

Set parameters for the Ethernet frame.
Item
Send Frame
*1

Jumbo Frame

*1 This setting is not available when the RJ71EN71 network type is set to "Q Compatible Ethernet".
Jumbo Frame
The following describes the precautions for using jumbo frames.
• In TCP/IP communications, the setting is enabled when the external device supports jumbo frames. If the external device
does not support jumbo frames, the Ethernet-equipped module sends data in normal frame size even though the "Jumbo
Frame" is enabled.
• In TCP/IP communications, data sending from the external device may fail when "Jumbo Frame" of the Ethernet-equipped
module is set to "Invalid (MTU 1500 byte)" and that of the external device is enabled. When communicating in jumbo
frames, enable the jumbo frame setting for both of the Ethernet-equipped module and external device.
• In UDP/IP communications, the Ethernet-equipped module sends data in jumbo frames according to the "Jumbo Frame"
even though the external device does not support jumbo frames.
• When the hub on the communication path does not support jumbo frames, the Ethernet-equipped module cannot
communicate with the external device because the hub discards the packets even if the module sends data in jumbo frame.
• Data can be sent in jumbo frames only when the transmission speed is 1Gbps. When "Automatic Negotiation" in
"Communication Speed" is set to "Jumbo Frame" and the Ethernet-equipped module communicates at a speed less than
1Gbps, the module sends data in the standard frame size.
• When the item other than "Automatic Negotiation" or "1Gbps/Full-Duplex" is set in "Communication Speed" of "Application
Settings", "Jumbo Frame" cannot be set to other than "Invalid (MTU 1500 byte)".

Communication Speed

Select the communication speed and communication mode from the following. (Default: Automatic Negotiation)
When "Automatic Negotiation" is selected, communication speed will be automatically set to be the same as that of another
device connected to the network.
• Automatic Negotiation
• 1Gbps/Full-Duplex
• 100Mbps/Half-Duplex
• 100Mbps/Full-Duplex
• 10Mbps/Half-Duplex
• 10Mbps/Full-Duplex
*1 This setting is not available when the RJ71EN71 network type is set to "Q Compatible Ethernet".
Select "Automatic Negotiation" to use 1Gbps/full-duplex.
2 PARAMETER SETTINGS
250
2.3 Application Settings
Description
Set the frame of the Ethernet header for the data link layer to be sent
by the RJ71EN71 or the RnENCPU (network part) to the Ethernet
(V2.0) frame.
Set the frame size of the data to be sent over Ethernet.
Set when the data transmission speed is 1Gbps and communication is
not efficient because the frame size is too small.
*1
Setting range
Ethernet (V2.0) Frame (fixed)
• Invalid (MTU 1500 byte)
• 2KB (MTU 2034 byte)
• 3KB (MTU 3058 byte)
• 4KB (MTU 4082 byte)
• 5KB (MTU 5106 byte)
• 6KB (MTU 6130 byte)
• 7KB (MTU 7154 byte)
• 8KB (MTU 8178 byte)
• 9KB (MTU 9004 byte)
(Default: Invalid (MTU 1500 byte))